United States President Joe Biden speaks in the East Room of the White House in Washington, DC on Wednesday, August 18, 2021.

Pete Marovich | Bloomberg | Getty Images

President Joe Biden again urged more Americans to get vaccinated against Covid-19 on Monday, saying the majority of deaths and hospitalizations in the United States from the virus are unvaccinated.

“Those who have been waiting for full approval should take their chance now,” Biden said during a press conference at the White House hours after the Food and Drug Administration completed the full Covid vaccine from Pfizer and BioNTech for people aged 16 and over Had granted approval.

He said the US agency had evaluated “mountains” of clinical study data and determined “without question” that the Covid syringe was safe and highly effective.

“The overwhelming majority of people hospitalized with Covid-19, or almost all of those who have died of Covid-19, are not vaccinated, not vaccinated,” he told reporters. “If you are fully vaccinated – both vaccinations plus two weeks – your risk of developing serious Covid-19 is very, very small.”

“Please get vaccinated now,” added Biden.

According to the agency, FDA scientists evaluated “hundreds of thousands of pages” of vaccine data from 40,000 study participants before granting approval. The two-dose vaccine was found to be 91% effective in preventing Covid – slightly lower than the 95% effectiveness rate study data shown when the vaccine was approved late last year and before the Delta variant prevailed in the USA

So far, the mRNA vaccine, marketed as Comirnaty, has been on the US market under emergency approval granted by the FDA in December. Since then, more than 204 million Pfizer shots have been administered, according to the Centers for Disease Control and Prevention.

Biden’s latest plea comes because coronavirus cases are still safe nationwide, filled by the highly contagious Delta variant. The president said U.S. health officials are beginning to see signs that new cases may decline in some regions of the nation. Still, he said, cases are increasing overall, especially among the unvaccinated.

US officials believe vaccination is the best way to stave off rising cases. According to the Centers for Disease Control and Prevention, about 51% of the entire US population will be fully vaccinated against Covid as of Sunday.

The US approval is expected to spark a new wave of vaccine mandates from American companies and schools. Large companies have already told some or all of their employees that they need to get a full Covid vaccination this fall. Still, despite having legal authority to do so, health experts say some private companies and other institutions may be reluctant to request the shots before full approval.

Earlier in the day, New York City officials said they are now requiring all 148,000 public school teachers and employees to receive their Covid-19 vaccine shots this fall. They had previously said that employees could avoid the vaccines if they had regular weekly Covid tests.

During his speech, Biden urged other schools and companies to prescribe the vaccine.

“All over the world people want these vaccines here in America,” he said. “They’re free, convenient, and waiting for you. So today please go for yourself, for your loved ones, for your neighbors, for your country.”

– CNBC’s Rich Mendez and Bob Towey contributed to this report.