A doctor draws a syringe of Moderna’s vaccine.
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A booster of Moderna’s Covid-19 vaccine triggered a promising immune response against variants B.1.351 and P.1, which were first identified in South Africa and Brazil, respectively, the company announced on Wednesday, citing early data from an ongoing clinical study.
In the study, Moderna is testing a 50 microgram dose of its vaccine in previously vaccinated people. The booster dose was found to increase neutralizing antibody responses against the original virus, as well as against B.1.351 and P.1, two variants that have since spread to other countries, including the United States
The company also said that a booster shot of its other vaccine, which it calls mRNA-1273.351, produced an even better immune response over its current vaccine against the B.1.351 variant from South Africa. The new vaccine is a variant-specific booster shot that targets B.1.351.
The preliminary results, which Moderna says will be published online, have not yet been peer-reviewed.
“As we seek to defeat the ongoing pandemic, we continue to seek to be proactive as the virus evolves,” said Stephane Bancel, CEO of Moderna, in a press release. “We are encouraged by this new data, which increases our confidence that our booster strategy should protect against these newly discovered variants.”
According to Moderna, the side effects were similar to those seen after the second dose of the vaccine in the previously reported studies. Side effects included injection site pain, fatigue and headache, and muscle and joint pain.
The new data comes as drug makers and scientists now say people will likely need a booster shot of Covid-19 vaccines and possibly additional shots each year, just like they did with seasonal flu.
Moderna’s vaccine requires two doses four weeks apart. As with Pfizer and Johnson & Johnson, the shot against Covid is very effective, although company executives and officials now say they expect this strong protection to wear off over time. Pfizer’s vaccine is also a two-dose therapy, while the J&J immunization is just one burst.
The Chief Medical Officer of the White House, Dr. Anthony Fauci, previously said that Americans may need booster vaccinations to better protect themselves from variants.
Earlier Wednesday, US health officials said highly contagious variants are still a “wild card” in their nationwide campaign to vaccinate most American adults by July 4th.
A report by the Centers for Disease Control and Prevention published on Wednesday predicted that Covid-19 cases will increase until May due to the highly contagious variant B.1.1.7 first identified in the UK, before declining sharply by July, because vaccinations reduce infections. Still, variants threaten to reverse the nation’s progress, officials said,
“We are seeing that our current vaccines protect against the pollutants circulating in the country. Put simply, the sooner more people are vaccinated, the sooner we will all get back to normal,” said CDC Director Dr. Rochelle Walensky during a Covid press conference at the White House.
Moderna is evaluating three approaches to increasing immunity. The first approach would use variant-specific booster vaccinations such as mRNA-1273.351, but at a lower dose than the original vaccine. The second would combine the original vaccine with a variant-specific vaccine into a single shot at 50 micrograms or less, Moderna said. The third would test a third shot of the original vaccine at a lower dose.
Bancel told CNBC last month that the company is hoping to have a booster shot for its two-dose vaccine in the fall.
