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Pfizer Covid vaccine 39% efficient in Israel, prevents extreme sickness

Pfizer Covid vaccine 39% effective in Israel, prevents severe illness

People will be given a dose of the Pfizer BioNTech Covid-19 vaccine at a Covid-19 mass vaccination center on Rabin Square in Tel Aviv, Israel on Monday January 4, 2020.

Kobi Wolf | Bloomberg | Getty Images

Pfizer and BioNTech’s Covid-19 vaccine is only 39% effective in Israel, where the Delta variant is the dominant strain, but still offers strong protection against serious illness and hospitalization, according to a new report from the country’s health ministry.

The efficacy figure, based on an unspecified number of people between June 20 and July 17, is down from a previous estimate of 64% two weeks ago and is in conflict with data from the UK that showed the Vaccination was 88% effective against symptoms, disease caused by the variant.

However, the two-dose vaccine still works very well in preventing serious illness, showing 88% effectiveness against hospitalization and 91% effectiveness against serious illness, according to Israeli data released Thursday.

“We have to keep in mind that these vaccines can become less effective over time,” said Dr. Isaac Bogoch, professor of infectious diseases at the University of Toronto.

He stressed that the syringes are still highly effective in preventing serious infections and helping hospital systems not get overwhelmed in the colder months. “We are still in the Covid era and anything can happen,” he said.

“We have to be prepared and we have to be agile that at some point people will need a booster,” he added. “This close monitoring, which is happening in places like Israel, the UK and other parts of the world, will be very helpful in moving policy forward when and when we need boosters.”

The Delta variant, which is already present in more than 104 countries, worries US health officials as they detect more breakthrough infections in fully vaccinated people, even though they are milder.

The Chief Medical Officer of the White House, Dr. Anthony Fauci said people who are fully vaccinated should consider wearing masks indoors as a precaution against the rapidly spreading variant in the US

“Of course we don’t want to see that,” said Fauci on Wednesday, referring to the so-called breakthrough infections. “This virus is very different from the viruses and variants that we have previously experienced. It has an exceptional ability to transmit from person to person.”

Dr. Paul Offit, who advises the FDA on Covid vaccines, said that while the vaccines still offer great protection against serious illness and death, they may not work as well against mild cases or the transmission of the disease to others.

He urged more Americans to get vaccinated, saying Delta was a highly contagious virus and the vaccinations would help people get seriously ill. Currently, less than half of the US population is fully vaccinated, according to data compiled by the CDC.

“This is rich and fertile soil for the virus to continue to reproduce and keep creating variants that may become increasingly resistant to vaccines or natural infections,” he said.

The report from Israel, which began vaccinating its people before many other countries, is likely to back up the arguments made by drug manufacturers that people will eventually need to be given a booster to protect themselves from new variants.

Pfizer said earlier this month that immunity is waning from its two-dose vaccine and is now planning to seek approval from the Food and Drug Administration for a booster dose. However, federal officials say that fully vaccinated Americans do not currently require additional vaccinations.

In a statement to CNBC, Pfizer said it remains confident that its two-dose regimen will protect against the coronavirus and its variants.

Still, it said a third dose might help after analysis from its Phase III study showed a decrease in effectiveness against symptomatic infections after four to six months.

“Initial data from a third dose of the current vaccine shows that a booster dose given at least 6 months after the second dose induces high neutralization titers against wild-type and beta that are 5 to 10 times higher than after two primary doses. “Said the company.

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Pfizer to make case to U.S. officers Monday

Pfizer to make case to U.S. officials Monday

Long Beach City Department of Health & Human Services is hosting an evening COVID-19 Vaccination Clinic on Long Beach City College Pacific Coast Campus. on Tuesday, July 6, 2021 in Long Beach, CA.

Francine Orr | Los Angeles Times | Getty Images

Pfizer meets with federal health officials on Monday to discuss the need for Covid-19 vaccine booster vaccinations as the drug company prepares for U.S. approval for a third vaccination, the company confirmed.

The meeting comes amid a public dispute between the drug maker and U.S. officials as to whether and when Americans will need additional doses of the Covid vaccines. Pfizer announced on Thursday that its two-dose vaccine, developed with German partner BioNTech, has seen a decrease in immunity and is now planning to apply for approval for a booster dose.

But shortly after Pfizer’s announcement, the Centers for Disease Control and Prevention and the Food and Drug Administration issued a joint statement condemning the company’s comments saying that Americans who were fully vaccinated against Covid are currently do not need a booster vaccination.

The debate about booster vaccination comes as the public becomes increasingly concerned about the highly communicable Delta variant – which is already the predominant form of the disease in the US – and whether current regimens of approved vaccines provide adequate protection.

Invitees include White House Chief Medical Officer Dr. Anthony Fauci, Dr. Francis Collins, Director of the National Institutes of Health, CDC Director Dr. Rochelle Walensky and Acting FDA Commissioner Dr. Janet Woodcock.

The White House and the Department of Health declined to comment.

“It’s very unusual and frustrating,” said Dr. Paul Offit, who advises the FDA on Covid vaccines, about the meeting on Monday. “Pfizer is a pharmaceutical company. You are not a public health agency. It is not up to them to determine how this vaccine will be distributed in terms of booster doses. That depends on the epidemiological work of the CDC. “

Offit said there is currently no data to suggest that most Americans still need booster doses. If officials see an increase in the percentage of fully vaccinated people who go to hospital or die, it could be time for the booster, he said.

“Right now that percentage is less than 1%,” he said. “Maybe over a year it’s 5% and a year later it’s 10-20%” of hospital admissions and deaths are fully vaccinated people.

Pfizer has cited data from Israel showing that its vaccine continues to be highly effective in serious illness and death, but wears off in mild cases.

Last week, Israeli officials reported a decrease in the effectiveness of the Pfizer BioNTech vaccine in preventing infections and symptomatic diseases, but said it remained highly effective in preventing serious diseases.

Dr. Isaac Bogoch, professor of infectious diseases at the University of Toronto, called Israel’s report on vaccine effectiveness “flawed” because it was an observational study from a single source.

People want to say, “Delta is going into vaccines,” he said. “That is not the case. This is quickly becoming the disease of the unvaccinated. We have to learn to differentiate between infection and disease.”

He said the vaccines in the US offer “excellent protection against” variants, including Delta.

“There may be a need for boosters in select populations, such as the immunocompromised, and we should be receptive to the need for boosters in the general population. But there doesn’t seem to be a need right now, ”he said hey.

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Citing the Delta Variant, Pfizer Will Pursue Booster Pictures and a New Vaccine

Citing the Delta Variant, Pfizer Will Pursue Booster Shots and a New Vaccine

Pfizer and BioNTech announced Thursday that they are developing a version of the coronavirus vaccine that will target Delta, a highly contagious variant that has spread to nearly 100 countries. The companies expect to begin clinical trials of the vaccine in August.

Pfizer and BioNTech also reported promising results from studies of people who received a third dose of the original vaccine. A booster shot six months after the second dose of the vaccine increases the effectiveness of the antibodies against the original virus and beta variant by five to ten-fold, the companies say.

The vaccine’s effectiveness could decline six months after immunization, the companies said in a press release, and booster doses may be needed to fight off virus variants.

The data were neither published nor peer-reviewed. The vaccine manufacturers said they expected to submit their results to the Food and Drug Administration in the coming weeks, a step toward approval for booster shots.

But the companies’ claims contradict other research, and several experts dismissed the claim that boosters are needed.

“Given the variants currently circulating, there is really no evidence of a third booster or a third dose of an mRNA vaccine,” said Dr. Celine Gounder, an infectious disease specialist at Bellevue Hospital Center in New York. “In fact, many of us wonder if you’ll ever need boosters.”

Federal authorities also sounded dubious on Thursday night. In general, Americans who have been fully vaccinated currently do not need a booster vaccination, the FDA and the Centers for Disease Control and Prevention said in a joint statement.

“We are prepared for booster doses when science shows they are needed,” the authorities said.

The Delta variant, first identified in India, is believed to be about 60 percent more contagious than Alpha, the version of the virus that ripped through the UK and much of Europe earlier this year, and perhaps twice as contagious as the original coronavirus.

The delta variant is now causing outbreaks among unvaccinated populations in countries like Malaysia, Portugal, Indonesia and Australia. In the USA, too, Delta is now the dominant variant, the CDC reported this week.

Until recently, infections in the US were at their lowest level since the pandemic began. Hospital stays and deaths related to the virus have continued to decline, but new infections could increase.

It is not yet clear to what extent the variant is responsible for this; A slower vaccination campaign and quick reopenings also play a role.

Citing data from Israel, Pfizer and BioNTech suggest that the effectiveness of their vaccine “in preventing infections and symptomatic illnesses decreased six months after vaccination.” Given the surge in Delta and other variants, the companies said “a third dose may be required within 6 to 12 months of full vaccination”.

Updated

July 11, 2021 at 1:57 p.m. ET

Health officials in Israel have estimated that full vaccination with the Pfizer BioNTech is only 64 percent effective against the Delta variant. (It is more than 90 percent effective against the original virus.)

But Israel’s estimates have been disproved by a number of other studies which found the vaccine to be very effective at preventing infection – against all variants. For example, a recent study showed that mRNA vaccines like those from Pfizer trigger a sustained immune response in the body that can protect against the coronavirus for years.

“Pfizer is looking opportunistic by putting an announcement on the back of very early and undigested data from Israel,” said John Moore, a virologist at Weill Cornell Medicine in New York. “When the time comes to use boosters here, the decision is not up to you.”

The companies described their plan to develop a new vaccine against Delta as a kind of backup measure in case the original vaccine replenishment fails. The new vaccine targets all of the spike protein, not a portion, and the first batch has already been made.

The delta variant poses challenges for the immune system. In the journal Nature on Thursday, French researchers reported new evidence that the delta variant can partially bypass the body’s immune response, as changes to the spike protein on its surface make it difficult for antibodies to attack.

The team analyzed blood samples from 59 people after they received the first and second doses of the vaccine. Blood samples from just 10 percent of those immunized with a dose of the AstraZeneca or Pfizer-BioNTech vaccines were able to neutralize the Delta and Beta variants in laboratory tests.

“A single dose of Pfizer or AstraZeneca was either poorly effective or not effective at all against beta and delta variants,” the researchers concluded. Data from Israel and the UK largely support this finding, although those studies also suggested that one dose of vaccine was still enough to prevent hospitalization or death from the virus.

But a second dose increased the effectiveness to 95 percent. There was not much difference in the levels of antibodies produced by the two vaccines.

“When you receive two doses of an mRNA vaccine, you are very well protected against serious illness, hospitalization and death for each of the variants,” said Dr. Gounder.

The researchers also looked at blood samples from 103 people infected with the coronavirus. Delta was much less sensitive than Alpha to samples from unvaccinated individuals in this group, the study found.

One dose of vaccine increased sensitivity significantly, suggesting that people who have recovered from Covid-19 may still need to be vaccinated to fight off some variants.

Taken together, the results suggest that two doses of the vaccine provide strong protection against all variants, as does one dose for people who have recovered from Covid-19 and have some natural immunity.

Some experts also questioned discussions about boosters for Americans while much of the world has not yet received a single dose.

“It’s impossible to ignore the global situation,” said Natalie Dean, biostatistician at Emory University in Atlanta. “I find it hard to imagine getting a third dose when there are front line workers treating Covid patients who have not yet been vaccinated.”

Every unvaccinated person offers the virus additional opportunities to mutate into dangerous variants, said Dr. Gounder feast.

“If we are concerned about variants,” she said, “our best protection is to get the rest of the world vaccinated, and not to hoard more doses to give people here in the US third doses of mRNA vaccines. “

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Pfizer says it’s growing a Covid booster shot to focus on the extremely transmissible delta variant

Pfizer says it is developing a Covid booster shot to target the highly transmissible delta variant

Pfizer and BioNTech announced Thursday that they are developing a Covid-19 booster vaccine that will target the Delta variant amid concerns about the highly communicable strain that is already the predominant form of the disease in the United States.

The companies said that while they believe a third vaccination of their current two-dose vaccine has the potential to maintain the “highest level of protection” against all currently known variants, including Delta, they are “vigilant” and are developing an updated version of the Vaccine.

“As evidenced by real evidence from the Israeli Ministry of Health, the effectiveness of the vaccine has declined six months after vaccination, while at the same time the Delta variant is becoming the dominant variant in the country,” the companies said in a written statement.

“These results are consistent with an ongoing analysis of the companies’ Phase 3 study,” they said. “This is why we have said, and continue to believe, that all of the data we have, it is likely that a third dose may be required within 6 to 12 months of full vaccination.”

Clinical trials could begin as early as August, subject to regulatory approvals, the companies said.

The announcement comes on the same day the Olympic Games organizers said they would be banning all viewers from the Games this year after Japan declared a state of emergency designed to stem a wave of new Covid-19 infections that are partly due to the Delta variant is due.

Delta is estimated by the World Health Organization to be about 55% more transmissible than Alpha, the variant first found in the UK that once dominated the US, didn’t do as well at protecting against mild illnesses and the spread of the disease to others, scientists say.

On Monday, Israeli officials reported a decrease in the effectiveness of the Pfizer BioNTech vaccine in preventing infections and symptomatic diseases, but said it remained highly effective in preventing serious diseases.

In the US, health officials are urging all eligible Americans to get vaccinated as soon as possible, especially before the fall season when Delta is expected to lead to a further surge in new coronavirus cases, especially in places with the lowest vaccination rates.

There are about 1,000 counties in the U.S. with a Covid vaccination rate of less than 30%, mostly located in the Southeast and Midwest, said CDC Director Dr. Rochelle Walensky recently. In these areas, the authority already sees increasing infection rates due to the further spread of the delta variant.

Pfizer and BioNtech executives have repeatedly said that people will likely need a booster vaccination or a third dose within 12 months of full vaccination, as they expect vaccine-induced immunity to wear off over time. They also said that people are likely to have to take extra shots every year.

Pfizer and BioNTech are developing booster vaccines and are expected to apply for US approval for a third dose of their vaccine shortly.

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Pfizer and Moderna Vaccines Prone to Produce Lasting Immunity, Research Finds

Pfizer and Moderna Vaccines Likely to Produce Lasting Immunity, Study Finds

The vaccines from Pfizer-BioNTech and Moderna trigger a sustained immune response in the body that can protect against the coronavirus for years, scientists reported on Monday.

The results add to the growing evidence that most people immunized with the mRNA vaccines may not need a booster dose as long as the virus and its variants do not progress much beyond their current forms – which is not guaranteed. People who have recovered from Covid-19 before they were vaccinated may not need a booster vaccination, even if the virus goes through a significant transformation.

“It’s a good sign of how persistent our immunity to this vaccine is,” said Ali Ellebedy, an immunologist at Washington University in St. Louis who led the study, which was published in the journal Nature.

The study did not take into account the coronavirus vaccine manufactured by Johnson & Johnson, but Dr. Ellebedy said he believed the immune response was less permanent than that of mRNA vaccines.

Dr. Ellebedy and colleagues reported last month that in people who survived Covid-19, immune cells that recognize the virus remain dormant in the bone marrow for at least eight months after infection. A study by another team showed that so-called memory B cells continue to mature and strengthen for at least a year after infection.

Based on these results, the researchers suggested that immunity in people infected with the coronavirus and later vaccinated could last for years, possibly a lifetime. However, it was unclear whether vaccination alone could have a similar long-lasting effect.

Dr. Ellebedy addressed this question by examining the source of memory cells: the lymph nodes, where immune cells train to recognize and fight the virus.

After an infection or vaccination, a specialized structure forms in the lymph nodes, the germinal center. This structure is sort of an elite school for B cells – a boot camp in which they become increasingly sophisticated and learn to recognize a multitude of viral genetic sequences.

The greater the range and the longer these cells have to practice, the more likely they are to thwart any virus variants that may appear.

“Everyone is always focused on developing the virus – this shows that the B cells are doing the same,” said Marion Pepper, an immunologist at the University of Washington in Seattle. “And it will protect against the continued development of the virus, which is really encouraging.”

After an infection with the coronavirus, the germinal center forms in the lungs. But after the vaccination, the cells are formed in the lymph nodes in the armpits that researchers can reach.

Updated

July 2, 2021, 5:06 p.m. ET

Dr. Ellebedy and colleagues recruited 41 people – including eight with a history of infection with the virus – who were immunized with two doses of the Pfizer BioNTech vaccine. The team collected lymph node samples from 14 of these people three, four, five, seven and 15 weeks after the first dose.

This meticulous work makes this a “heroic study,” said Akiko Iwasaki, an immunologist at Yale. “This kind of careful time history analysis in humans is very difficult.”

Dr. Ellebedy found that 15 weeks after the first dose of the vaccine, the germinal center was still highly active in all 14 participants and that the number of memory cells that recognized the coronavirus had not decreased.

“The fact that the reactions lasted almost four months after the vaccination – that’s a very, very good sign,” said Dr. Ellebedy. Sprouting centers typically peak one to two weeks after vaccination and then decrease.

“Usually there isn’t much left after four to six weeks,” said Deepta Bhattacharya, an immunologist at the University of Arizona. But germinal centers that are stimulated by the mRNA vaccines “still go in, months, and most people don’t go back much”.

Dr. Bhattacharya noted that most of what scientists know about the persistence of germinal centers is based on animal studies. The new study shows for the first time what happens to people after vaccination.

The results suggest that the vast majority of those vaccinated will be protected in the long term – at least against the existing coronavirus variants. But older adults, people with weak immune systems, and those taking drugs that suppress immunity may need boosters; People who survived Covid-19 and were later vaccinated may not need it at all.

It is difficult to predict exactly how long protection against mRNA vaccines will last. In the absence of variants that bypass immunity, immunity could theoretically last a lifetime, experts said. But the virus is clearly evolving.

“Anything that would actually require a refresher would be variant-based, not immunity waning,” said Dr. Bhattacharya. “I just don’t see it.”

People who have been infected with the coronavirus and then immunized see a sharp spike in their antibody levels, likely because their memory B cells – which produce antibodies – had many months to develop before vaccination.

The good news: a booster vaccine is likely to have the same effect on people who have been vaccinated as a previous infection, said Dr. Ellebedy. “If you give them another chance to get involved, they’ll have a massive response,” he said, referring to memory B cells.

In terms of boosting the immune system, vaccination is “probably better” than recovering from the actual infection, he said. Other studies have shown that the repertoire of memory B cells produced after vaccination is more diverse than that produced by infection, suggesting that the vaccines protect against variants better than natural immunity alone.

Dr. Ellebedy said the results also suggest that these signs of sustained immune response could be caused by mRNA vaccines alone, as opposed to those made by more traditional means like Johnson & Johnson’s.

But that’s an unfair comparison because the Johnson & Johnson vaccine is given as a single dose, said Dr. Iwasaki: “If the J&J had a booster, they might get the same kind of reaction.”

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Las vacunas de Pfizer y Moderna podrían generar una inmunidad duradera, según científicos

Las vacunas de Pfizer y Moderna podrían generar una inmunidad duradera, según científicos

Las vacunas fabricadas por Pfizer-BioNTech y Moderna generan una reacción inmunitaria persistente en el organismo que puede proteger contra el coronavirus durante años, informó el lunes un grupo de científicos.

Los hallazgos se suman a la creciente evidencia de que la mayoría de las personas inmunizadas con las vacunas de ARNm podrían no necesitar refuerzos, siempre y cuando el virus y sus variantes no evolucionen mucho más allá de sus formas actuales, algo que no está garantizado. Es posible que las personas que se recuperaron de COVID-19 antes de ser vacunadas no necesiten refuerzos incluso si el virus realiza una transformación significativa.

“Es una buena señal de lo durable que es nuestra inmunidad proveniente de esta vacuna”, dijo Ali Ellebedy, inmunólogo de la Universidad de Washington en Saint Louis que dirigió el estudio, publicado en la revista Nature.

El estudio no incluyó a la vacuna fabricada por Johnson & Johnson, sin embargo, el doctor Ellebedy dijo que esperaba que la respuesta inmunitaria sea menos durable que la que producen las vacunas de ARN mensajero.

Ellebedy y sus colegas reportaron el mes pasado que en quienes sobreviven a la COVID-19, las células inmunitarias que reconocen al virus permanecen inactivas (durmientes) en la médula ósea durante al menos ocho meses después de la infección. Un estudio de otro equipo indicó que las llamadas células B de memoria siguen madurando y fortaleciéndose durante al menos un año tras la infección.

Los investigadores, con fundamento en esos hallazgos, sugirieron que la inmunidad podría durar por años y tal vez toda la vida en las personas que contrajeron el coronavirus y luego fueron vacunadas. Pero no quedó muy claro si es posible conseguir un efecto tan duradero solo con la vacunación.

El equipo de Ellebedy buscó resolver esa pregunta al examinar la fuente de las células de memoria: los nódulos linfáticos, donde las células inmunitarias se entrenan para reconocer y combatir el virus.

Después de una infección o la vacunación, se forma una estructura especializada llamada centro germinal en los ganglios linfáticos. Esta estructura es una suerte de escuela de élite para las células B, un campo de entrenamiento donde se vuelven cada vez más sofisticadas y aprenden a reconocer un conjunto diverso de secuencias genéticas virales.

Es más probable que estas células logren frustrar a las variantes del virus que puedan surgir si disponen de más tiempo y rango para practicar.

“Todos se enfocan siempre en la evolución del virus; esto muestra que las células B están haciendo lo mismo”, dijo Marion Pepper, inmunóloga de la Universidad de Washington en Seattle. “Y va a proteger contra la evolución en curso del virus, lo cual es realmente alentador”.

Después de contraer el coronavirus, se forma el centro germinal en los pulmones. Pero después de la vacunación, la educación de las células sucede en los nódulos linfáticos de las axilas, al alcance de los investigadores.

Ellebedy y sus colegas reclutaron a 41 personas, incluidas ocho con antecedentes de infección por el virus, que fueron inmunizadas con dos dosis de la vacuna Pfizer-BioNTech. De 14 de estas personas, el equipo extrajo muestras de los ganglios linfáticos a las tres, cuatro, cinco, siete y 15 semanas después de la primera dosis.

Ese laborioso trabajo es lo que hace que este sea un “estudio heróico”, comentó Akiko Iwasaki, inmunólogo de Yale. “Este tipo de análisis cuidadoso de series de tiempo en humanos es muy difícil de realizar”.

El equipo de Ellebedy encontró que a las 15 semanas de recibir la primera dosis de la vacuna, el centro germinal seguía altamente activo en los 14 participantes y que la cantidad de células de memoria capaces de reconocer al coronavirus no había disminuido.

“Que las reacciones continuaran casi cuatro meses después de la vacunación, es una señal muy muy buena”, comentó Ellebedy. Los centro germinales suelen tener su máxima expresión una o dos semanas después de la inmunización y luego declinan.

“Por lo general no suele quedar mucho después de cuatro a seis semanas”, dijo Deepta Bhattacharya, inmunólogo de la Universidad de Arizona. Pero los centros germinales estimulados por las vacunas de ARNm “siguen activas a los meses y no declinan mucho en la mayoría de las personas”.

Bhattacharya indicó que la mayor parte de lo que los científicos saben sobre la persistencia de los centros germinales proviene de la investigación con animales. El nuevo estudio es el primero en mostrar lo que sucede en las personas después de la vacunación.

Los resultados sugieren que una gran mayoría de las personas vacunadas estarán protegidas a largo plazo, al menos contra las variantes de coronavirus existentes. Pero los adultos mayores, las personas con sistemas inmunitarios débiles y aquellos que toman medicamentos inmunosupresores puede que necesiten refuerzos; Es posible que las personas que sobrevivieron a la COVID-19 y luego fueron inmunizadas nunca los necesiten.

Es difícil predecir con exactitud cuánto durará la protección de las vacunas de ARN mensajero. Si no existieran las variantes que esquivan a la inmunidad, esta podría durar en teoría toda la vida. Pero el virus claramente sigue evolucionando.

“Cualquier necesidad de un refuerzo sería a causa de una variante, no de un declive de la inmunidad”, dijo Bhattacharya. “No veo que eso llegue a suceder”.

Las personas que se infectaron con el coronavirus y luego se inmunizaron experimentan un aumento importante en sus niveles de anticuerpos, muy probablemente porque sus células B de memoria, que producen anticuerpos, tuvieron muchos meses para evolucionar antes de la vacunación.

La buena noticia: la vacuna de refuerzo probablemente tendrá el mismo efecto que una infección previa en personas inmunizadas, dijo Ellebedy. “Si les brindas otra oportunidad de participar, responderán de forma masiva”, dijo, refiriéndose a las células B de memoria.

En lo que respecta a reforzar el sistema inmunológico, la vacunación es “probablemente mejor” que recuperarse de la infección real, dijo. Otros estudios han sugerido que el repertorio de células B de memoria que se producen después de la vacunación es más diverso que el generado por la infección, lo que sugiere que las vacunas protegen mejor contra variantes que la inmunidad natural por sí sola.

Ellebedy dijo que los resultados también sugieren signos de una reacción inmunitaria persistente producidos por las vacunas de ARNm, en lugar de por aquellas más tradicionales, como la de Johnson & Johnson.

Pero esa es una comparación injusta, ya que la vacuna de Johnson & Johnson se administra en una sola dosis, dijo Iwasaki: “Es probable que si la J & J tuviera una segunda dosis, podría inducir el mismo tipo de respuesta”.

Apoorva Mandavilli es reportera del Times y se enfoca en ciencia y salud global. En 2019 ganó el premio Victor Cohn a la Excelencia en Reportaje sobre Ciencias Médicas. @apoorva_nyc

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Mixing Pfizer, AstraZeneca Vaccines Provides Sturdy Covid Safety, Research Finds

Mixing Pfizer, AstraZeneca Vaccines Gives Strong Covid Protection, Study Finds

Initial results from a UK vaccine study suggest that mixing different brands of vaccine can produce a protective immune response against Covid-19. In the study, volunteers produced high levels of antibodies and immune cells after receiving a dose of the Pfizer BioNTech vaccine and a dose of the AstraZeneca Oxford shot.

Giving the vaccines in any order will likely provide effective protection, said Dr. Matthew Snape, a vaccines expert at Oxford University, at a news conference Monday. “Any of these schedules I think could be argued and expected to be effective,” he said.

Dr. Snape and his colleagues began the study called Com-COV in February. In the first wave of the study, they gave 830 volunteers one of four vaccine combinations. Some received two doses from Pfizer or AstraZeneca, both of which have been shown to be effective against Covid-19. Others got a dose of AstraZeneca, followed by one from Pfizer, or vice versa.

With the first wave of volunteers, the researchers waited four weeks between doses. Studies have shown that the AstraZeneca vaccine offers greater protection when the second dose is delayed for up to 12 weeks. Therefore, the researchers are also conducting a separate 12-week study that should provide results over the next month.

The researchers found that volunteers reported more chills, headaches, and muscle aches than people who received two doses of the same vaccine. But the side effects were short-lived.

Dr. Snape and his colleagues then took blood samples to measure the immune response in the volunteers. They found that those who received two doses of Pfizer-BioNTech produced antibody levels about 10 times higher than those who received two doses of AstraZeneca. Volunteers who received Pfizer followed by AstraZeneca showed antibody levels about five times higher than those who received two doses of AstraZeneca. And volunteers who received AstraZeneca followed by Pfizer achieved antibody levels about as high as those who received two doses of Pfizer.

Dr. Snape said the differences would most likely decrease in the volunteers who received a second dose after 12 weeks when the AstraZeneca vaccine had more time to intensify its effects.

The study also found that using different vaccines produced higher levels of immune cells prepared to attack the coronavirus than when giving two doses of the same vaccine. Dr. Snape said it was not yet clear why mixing had this advantage. “It’s very fascinating, let’s say so much,” he said.

Dr. Snape and colleagues have started a similar study, adding Moderna and Novavax vaccines to their list of possibilities.

For now, he said, the best course of action remains to get two doses of the same vaccine. Large clinical studies have clearly shown that this strategy reduces the likelihood of developing Covid-19. “Your default should be what has been shown to work,” said Dr. Snape.

But there are many cases where that is not possible. Vaccine deliveries are sometimes delayed due to manufacturing issues, for example. Younger people in some countries have been advised not to receive a second dose of AstraZeneca due to concerns about the low risk of blood clots. In situations like this, it’s important to know if people can switch to another vaccine.

“This provides reassuring evidence that should work,” said Dr. Snape.

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FDA provides warning of uncommon coronary heart irritation to Pfizer, Moderna vaccines

CDC group says there isn't enough data yet to recommend booster shots

Vials with Pfizer-BioNTech and Moderna coronavirus disease (COVID-19) vaccine labels are seen in this illustration picture taken March 19, 2021.

Dado Ruvic | Reuters

The U.S. Food and Drug Administration on Friday added a warning to patient and provider fact sheets for the Pfizer and Moderna Covid-19 vaccines to indicate a rare risk of heart inflammation.

For each vaccine, the fact sheets were revised to include a warning about myocarditis and pericarditis after the second dose and with the onset of symptoms within a few days after receiving the shot.

Myocarditis is the inflammation of the heart muscle and pericarditis is the inflammation of the tissue surrounding the heart. Health officials said the benefits of receiving the vaccine still outweigh any risk.

“The risk of myocarditis and pericarditis appears to be very low given the number of vaccine doses that have been administered,” Janet Woodcock, acting FDA commissioner, said in a statement.

“The benefits of Covid-19 vaccination continue to outweigh the risks, given the risk of Covid-19 diseases and related, potentially severe, complications,” she said.

The FDA update follows a review and discussion by the Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices meeting on Wednesday. 

There have been more than 1,200 cases of a myocarditis or pericarditis mostly in people 30 and under who received the shots, according to presentation slides from the CDC meeting.

About 300 million shots had been administered as of June 11, according to the CDC. There have been just 12.6 heart inflammation cases per million doses for both vaccines combined.

— CNBC’s Berkeley Lovelace Jr. contributed reporting

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Biden to Ship Thousands and thousands of Pfizer Vaccine Doses to 100 Nations

Biden to Send Millions of Pfizer Vaccine Doses to 100 Countries

WASHINGTON – President Biden, under pressure to aggressively address the global coronavirus vaccine shortage, will announce Thursday that his government will buy 500 million doses of the Pfizer BioNTech vaccine and deliver them to about 100 countries next year The donation will be made by people familiar with the plan.

The White House reached the deal just in time for Mr Biden’s eight-day tour of Europe, which will be his first opportunity to assert the United States as world leader and to re-establish ties that have been badly frayed by President Donald J. Trump.

“We have to end Covid-19, not just at home we do, but everywhere,” Biden told American troops after landing at RAF Mildenhall in Suffolk, England. “There is no wall high enough to protect us from this pandemic or the next biological threat we face, and there will be others. It requires coordinated multilateral action. “

People familiar with the Pfizer deal said the United States would pay for the cans at a “not for profit” price. The first 200 million cans will be distributed by the end of this year, followed by 300 million by next June, they said. The doses will be distributed through Covax, the international vaccine exchange initiative.

Mr Biden is in Europe for a week to attend the NATO and Group of 7 summits and to meet with President Vladimir V. Putin in Geneva. He will likely use the trip to urge other nations to step up vaccine distribution.

In a statement Wednesday, Jeffrey D. Zients, White House official in charge of developing a global vaccination strategy, said Biden will “bring the world’s democracies together to resolve this global crisis, with America leading the way, the vaccine arsenal that will be of vital importance in our global fight against Covid-19. “

The White House is trying to highlight its success in fighting the pandemic – especially its vaccination campaign – and using that success as a diplomatic tool, especially as China and Russia are trying to do the same. Mr Biden has insisted that unlike China and Russia, who share their vaccines with dozens of countries, the United States will not attempt to extort promises from countries that receive US-made vaccines.

The 500 million doses are still well below the 11 billion the World Health Organization estimates to vaccinate the world, but well above what the United States has promised so far. Other nations have asked the United States to give up some of its ample vaccine supplies. In some African countries, less than 1 percent of people are fully vaccinated compared to 42 percent in the United States and the United Kingdom.

Global health advocates welcomed the news but reiterated their stance that it is not enough for the United States to simply give away vaccines. They say the Biden government needs to create the conditions for other countries to manufacture vaccines themselves, including transferring technology to make the cans.

“The world desperately needs new productions to produce billions more doses within a year, not just pledges to buy planned inadequate supplies,” Peter Maybarduk, director of the Citizens’ Access to Medicines Program, said in a Explanation. He added, “We have not yet seen a US government or G7 plan with the ambition or urgency to add billions more doses and end the pandemic.”

The Pfizer deal has the potential to open the door to similar agreements with other vaccine makers, including Moderna, whose vaccine, unlike Pfizer’s, was developed with US taxpayers’ money. In addition, the Biden government has negotiated a deal whereby Merck will help manufacture Johnson & Johnson’s vaccine, and those doses may be available for use overseas.

The United States has already signed a contract to purchase 300 million doses of the Pfizer BioNTech vaccine, which requires two vaccinations to be distributed in the United States; the 500 million cans are on top of that, according to people familiar with the deal.

Biden in Europe

Updated

June 9, 2021, 8:50 p.m. ET

Neither Pfizer nor administrators would tell what the company is charging the government for the cans. Pfizer is also offering the Biden government the option to purchase an additional 200 million cans at cost to be donated overseas.

For Pfizer, the decision to sell so much of the supply to the Biden government for no profit is a significant step.

The vaccine accounted for $ 3.5 billion in sales for the first three months of this year, nearly a quarter of Pfizer’s total sales. By some estimates, the company made approximately $ 900 million in pre-tax income from the vaccine in the first quarter.

However, the company has also been criticized for disproportionately supporting wealthy nations, despite Pfizer’s CEO Albert Bourla promising in January to ensure that “developing countries have equal access to the rest of the world.”

The 200 million Pfizer cans the Biden government plans to donate accounts for about 7 percent of the three billion cans the company is expected to produce this year. Pfizer expects to deliver an additional 800 million doses to lower and lower middle income countries through other agreements with individual countries or Covax, a spokeswoman said.

For Mr Biden, the deal shows that his government is ready to intervene deeper in the treasury to help poorer countries.

Last week, Mr Biden said the United States would be distributing 25 million doses to countries in the Caribbean and Latin America this month; South and Southeast Asia; Africa; and the Palestinian Territories, Gaza and the West Bank.

These cans are the first of 80 million that Mr Biden intended to send abroad by the end of June; three quarters of these are sold by Covax. The rest will be used to address urgent and urgent crises in countries like India, the West Bank and Gaza Strip, government officials said. Many of the 80 million cans were manufactured by AstraZeneca and are still subject to a complex review by the Food and Drug Administration.

Mr Biden has also pledged to support a waiver of an international intellectual property treaty that would make it difficult for companies to refuse their technology. But European leaders are blocking the proposed exemption, and pharmaceutical companies are firmly against it. The World Trade Organization’s Trade-Related Aspects of Intellectual Property Rights Council meets this week to review the derogation.

The president’s promise of vaccines for the world market comes as he prepares on Thursday for a meeting with British Prime Minister Boris Johnson, who has urged leaders to pledge to feed everyone in the world by the end of 2022 vaccinate. Mr Biden’s announcement is likely welcome news to Mr Johnson, whose critics have questioned where the money will come from to keep his promise.

“The truth is, world leaders have been stepping down the street for months – to the point where they ran out of streets,” Edwin Ikhouria, executive director for Africa at ONE Campaign, a nonprofit that dedicated to eradicating global poverty, said in a statement on Wednesday.

About 64 percent of adults in the United States are at least partially vaccinated, and the president’s goal is to increase that number to 70 percent by July 4th, following an accessibility strategy and incentives to reach Americans who have not yet received any injections.

Despite these efforts, there are unused doses of vaccine that could be wasted. Once thawed, cans have a limited shelf life and millions could expire within two weeks, according to federal officials.

Equal access to vaccines has become one of the most persistent challenges in containing the pandemic. Wealthier nations and private corporations have pledged tens of millions of doses and billions of dollars to sustain global supplies, but the disparities in vaccine allocations so far have been stark.

Dr. Tedros Adhanom Ghebreyesus, director general of the World Health Organization, warned this week that the world is facing a “two-pronged pandemic” with countries short of vaccines struggling with virus cases even as better-served countries return to normal.

These lower-income countries will largely depend on wealthier ones until vaccines can be distributed and produced on a more equitable basis, he said.

Daniel E. Slotnik contributed the coverage from New York and Michael D. Shear from Plymouth, England.

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Pfizer and Moderna Pictures Are Powerfully Efficient in opposition to Virus, Evaluation Says

Pfizer and Moderna Shots Are Powerfully Effective against Virus, Analysis Says

Pfizer-BioNTech and Moderna Coronavirus vaccines are 94 percent effective at preventing symptomatic Covid-19 disease, according to a new study of 1,800 US healthcare workers.

The research the Centers for Disease Control and Prevention published on Friday provides even more evidence that the vaccines work well outside of controlled clinical trials.

“This report provided the most compelling information yet that Covid-19 vaccines are working as expected in the real world,” said Dr. Rochelle Walensky, CDC director, in a statement Friday.

“This study, which was added to the many previous studies, was instrumental in changing the CDC’s recommendations for those fully vaccinated against Covid-19.”

The results are based on an ongoing study of healthcare workers in 25 states. This interim analysis included data on 1,843 healthcare workers who were routinely tested for coronavirus infection. More than 80 percent of the participants were female.

About 623 workers tested positive between January and mid-March. Those who were fully vaccinated were 94 percent less likely to develop symptomatic coronavirus infections than their unvaccinated counterparts, the researchers found. The numbers are consistent with the effectiveness estimates from the clinical studies.

The scientists also found that a single dose of the two-shot regimen was 82 percent effective in preventing symptomatic infection. This number is higher than reported in other studies and may be due to the relative youth of the study participants, who had an average age of 37 to 38 years. Less than 2 percent were 65 years of age or older.

CDC scientists had previously found that fully vaccinated health, frontline, and essential workers were 90 percent less likely to get coronavirus. These results helped allay fears that vaccinated people might even asymptomatically transmit the virus and spread it to others.

Concern was a major reason for asking vaccinated Americans to continue wearing masks, a recommendation the CDC overturned Thursday.