The US FDA on November 19 decided to approve booster doses of Pfizer and Moderna vaccines for all adults, instead of limiting the audience as before.
The move expands eligibility for the booster dose to all US citizens 18 years of age and older, fulfilling an earlier pledge by President Joe Biden. The program is implemented in 10 states. If the Centers for Disease Control and Prevention (CDC) also approves, all adults in the US who have received two doses of Moderna and Pfizer vaccines at least 6 months ago will receive a booster dose.
The US Food and Drug Administration (FDA) made this decision because of concerns that the vaccine’s effectiveness in the winter would weaken, leading to a breakthrough wave of nCoV infections. Previously, the US only accepted booster doses for people aged 50-64 years old with underlying medical conditions, people aged 18 years or older with underlying medical conditions, who were living in concentrated care facilities or working in the environment. high risk of infection.
Based on the results of a phase 3 trial with more than 10,000 volunteers, Pfizer said the vaccine dose increased 95% effectiveness in preventing symptomatic nCoV infection in the context of the Delta variant spreading. The company has asked the regulator to authorize a booster dose of the vaccine for all adults. Moderna made a similar move.
Over the past month, Dr. Anthony Fauci, America’s leading infectious disease expert, has repeatedly defended his views on booster vaccination for adults. He noted that antibody levels in fully vaccinated people decline over time.
A study in September by the US CDC showed that the vaccine’s effectiveness against nCoV infection decreased from 92% to 75% between 5 and 7 months after injection. The November study, published in the journal Science, found that the effectiveness of fighting the virus in military veterans dropped from 88% to 48% between February and October of this year.
Citing data from Israel, Eric Topol, director of the Scripps Research Institute in La Jolla, California, said the booster dose of the vaccine reduces the risk of symptomatic nCoV infection and reduces the likelihood of death in people 40 years of age and older. . “Highly effective booster dose prevents infection. That’s how we break the chain of nCoV transmission,” he said.
However, many experts still believe that the US should focus on the main vaccination program, ie give two doses of the vaccine to as many people as possible, instead of rushing to deploy booster doses. They point out that the current community infections are mostly unvaccinated people.
“The goal is to reduce severe infections, hospitalizations and deaths. We’re not even there yet. That’s what to focus on,” said Celine Gounder, infectious disease specialist at the Hospital Center Bellevue in New York, commented.
Despite the arguments of the scientific community, many localities have actively expanded the conditions for booster vaccination even without the approval of the management agency to prevent the Covid-19 wave in the autumn and winter.
Thuc Linh (Follow NY Times, WSJ)