US top health officials on Tuesday released the fourth dose of Covid vaccine for older adults amid uncertainty over whether an even more contagious version of Omicron will spark another wave of infections in the US like it has in Europe and China.
The FDA has approved fourth doses of Pfizer and Moderna for everyone ages 50 and older, and a fifth dose for certain younger people weakened immune system. Those 12 and older with a compromised immune system are eligible for a fifth dose of Pfizer, and those 18 and older with the same condition are eligible for Moderna.
The Centers for Disease Control and Prevention quickly undertook the decision, paving the way for those eligible to receive a new round of boosters. The CDC also recommended that all adults who have received two doses of Johnson & Johnson’s vaccine receive a third dose of either Pfizer or Moderna. Adults who received the J&J vaccine and a second injection of Pfizer or Moderna are not yet eligible for a third dose unless they are 50 years of age or older or have a compromised immune system.
All new booster vaccinations should be given no earlier than four months after the last vaccination.
The FDA and CDC made the decision to without convening meetings of their vaccine advisory committees, a rare step that agencies have taken more frequently over the course of the pandemic to expand the use of already approved Covid vaccines. The drug agency’s approval comes just two weeks after Pfizer and Moderna asked the FDA to approve a second booster shot based on data from Israel.
The FDA’s Vaccine Advisory Committee is scheduled to meet on April 6 to discuss the future of booster shots in the US. Vaccine experts are expected to have a broad discussion on booster shots and not vote on a specific recommendation.
dr Peter Marks, head of the FDA’s office responsible for vaccine safety and efficacy, said the drug agency did not call an advisory meeting because the decision was “relatively straightforward.”
“This fourth booster dose is something that evidence we now have from Israel suggests it may reduce the risk of hospitalization and death in this elderly population,” Marks said while speaking to reporters after the decision.
dr Paul Offit, a member of the committee, criticized the drug regulator for moving forward without a public meeting where the American public can hear experts weigh the data and give the FDA a recommendation on the best way forward. The recommendations of the Vaccination Advisory Board are non-binding, but contribute to transparency for the public.
“It’s just kind of a fait accompli,” Offit said of the FDA approval. “So that’s how it works? We talk endlessly about following the science – it doesn’t seem to work that way.”
The FDA hasn’t asked committee members to make a recommendation on booster shots since last fall, when they voted for a third dose of Pfizer or Moderna for people age 65 and older and younger at risk of severe Covid.
Health experts are divided on whether a fourth dose of vaccine is currently needed, although the debate is nuanced. There is broader agreement that the elderly or those with compromised immune systems may benefit from additional protection. Another booster shot for young, healthy adults is more controversial as they are less susceptible to serious illness from Covid.
dr Peter Hotez, a vaccines expert at Baylor College of Medicine in Houston, said some scientists believe the shots’ sole purpose was to keep people away from the hospital. However, Hotez said vaccination policy should also aim to prevent infection and long Covid. The effectiveness of Omicron’s third dose against hospital admissions has also decreased over time, he said.
The CDC published a study in February showing that the effectiveness of the third dose decreased in ER visits from 87% to 66% in ER visits and from 91% to 78% in hospital admissions four months after receiving the injection.
“This gives me concern that the boosters aren’t necessarily holding up as well as we would like,” said Hotez, who strongly advocates a fourth dose based on Israeli data showing that another booster could protect people increased above 60.
israeli scientists, in a study published last week, found that the mortality rate from Omicron in seniors ages 60 to 100 who received a fourth dose of Pfizer was 78% lower than those who received only three shots. The study, which was not peer-reviewed, examined the medical records of more than 500,000 people at Clalit Health Services, Israel’s largest healthcare provider, from January to February.
The FDA’s decision to allow fourth doses for people age 50 and older was broader than Pfizer’s requirement and narrower than Moderna’s. Pfizer had asked the FDA to clear fourth doses for people 65 and older, while Moderna asked the drug agency to approve them for all adults 18 and older. Moderna CEO Stephane Bancel told CNBC last week that the biotech had filed a broader application to give the FDA the flexibility to decide which age group now needs a fourth dose.
John Moore, a professor of microbiology and immunology at Weill Cornell Medical College, criticized Moderna’s call for a fourth dose for all adults as aggressive, blanket use that fails to differentiate between the different needs of older and younger people.
“The old and frail person needs an additional dose of vaccine much more than a young healthy athlete,” Moore said.
The approval of the fourth vaccination comes as a more contagious Omicron subvariant, BA.2, has caused new waves of infection in major European countries and China, which is grappling with its worst outbreak since 2020. BA.2 has been gaining ground in the US since February and looks set to become the dominant variant here in the coming weeks. White House medical adviser Dr. Anthony Fauci said infections in the US could increase due to BA.2, although he doesn’t expect another wave.
“We hope that by taking this action, we’ll help people take steps to protect themselves in case we have another wave that comes through this country,” Marks said.
BA.2 does not generally make people sicker than Omicron’s earlier version, BA.1, and the vaccines have the same efficacy against both types of the variant, according to studies from South Africa and Qatar, among others. None of the studies were peer-reviewed.
It’s unclear if the FDA will eventually allow fourth doses for younger adults as well, as there is currently less data to support such a decision. Marks said the US may need a more generalized under-50s refresher campaign in the autumn when Covid is likely to pick up again and immunity has waned. He also said the US may need to switch to a vaccine that targets a specific variant, like Omicron. The current vaccines were developed against the Wuhan strain.
A Israeli study of February among health workers aged 18 and older reported that a fourth dose does not boost immunity but restores it to the peak strength of the third dose. Many people in the study who received a fourth dose still became infected, even though they were either asymptomatic or had mild symptoms.
“A fourth shot of healthy young health workers may only have marginal benefits,” wrote Drs. Gili Regev-Yochay and a team of scientists from Sheba Medical Center and the Israel Ministry of Health who conducted the study, in a letter to the New England Journal of Medicine this month.
The FDA advisory committee voted overwhelmingly last September against a third dose for everyone ages 16 and older because experts felt there was insufficient data to support such a decision. Two months later, the FDA approved Moderna and Pfizer boosters for all adults without holding an advisory committee meeting, and then lowered the eligibility in December and January to include everyone 12 and older.
https://www.cnbc.com/2022/03/29/fda-authorizes-fourth-pfizer-covid-vaccine-dose-for-people-age-50-and-older-.html CDC recommends fourth doses of Pfizer and Moderna Covid vaccines for people age 50 and older