Research on Covid booster injections is contradictory



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Food and Drug Administration advisers on Friday questioned a key claim by researchers in Israel and pharmaceutical company Pfizer: that its coronavirus vaccine is declining in terms of protection not only against infection, but against disease. serious and hospitalization.

The advisers met to assess Pfizer’s request for approval of booster doses of vaccine for all Americans over 16 years of age. Among the details that have surfaced during the heated debate: Israel and the United States define critical illness differently.

In Israel, anyone with an accelerated respiratory rate and an oxygen level below 94% is seriously ill. In contrast, the Centers for Disease Control and Prevention considers people sick enough to be hospitalized as seriously ill, CDC scientist Dr. Sara Oliver said at the advisory committee meeting.

The gap could help explain why the two countries reported very different results in people who were fully immune.

Israeli researchers said they had seen a large number of hospital patients who had received two doses months earlier. But in the United States, the CDC has reported that vaccinated patients represent only 2% of people hospitalized for Covid-19.

This is just one of many scientific differences that have come to light this week.

In the journal The Lancet on Monday, an international team of scientists analyzed dozens of studies and concluded that boosters are not yet needed by the general population, and that the world would be better served by using doses of the vaccine for protect the billions of people who remain unvaccinated.

FDA scientists on Wednesday released an assessment online suggesting that they are also not convinced that there is enough evidence that boosters are needed.

“Overall, the data indicates that the Covid-19 vaccines currently licensed or authorized in the United States still provide protection against serious Covid-19 illness and death in the United States,” according to their executive summary.

But some FDA officials have publicly approved the booster shots. “The need for an additional dose at six months to provide longer term protection shouldn’t come as a surprise, as it is likely necessary for the generation of a mature immune response,” said Dr Peter Marks, the ‘one of the agency’s top officials, said at Friday’s meeting.

Alarmed by the increase in cases, Israeli officials have offered third doses of the vaccine to anyone over the age of 12. Israeli researchers published the first results of the deployment in the New England Journal of Medicine on Wednesday – but few outside scientists found the study convincing.

The team collected data on the effects of booster injections from the medical records of more than 1.1 million people over the age of 60. At least 12 days after the booster, infection rates were eleven times lower – and rates of severe illness nearly twenty times lower – among them. who received a booster compared to those who received only two doses, the researchers found.

The results are not surprising, according to experts, and do not indicate long-term benefit.

Credit…Amr Alfiky / The New York Times

“We have known for some time that vaccines cause less robust immune responses in the elderly,” said Dr Celine Gounder, infectious disease specialist at Bellevue Hospital Center and former advisor to the Biden administration. “Recommending additional doses of vaccine for the elderly is not controversial. “

Vaccination remains powerfully protective against serious illness and hospitalization in the vast majority of people in all studies published so far, experts said. But the vaccines appear to be less potent against infections in people of all ages, especially those exposed to the highly contagious Delta variant.

Cumulative data so far suggests that only the elderly will need boosters, a view underscored by the FDA advisory committee, which voted Friday to approve the recalls only for Americans aged 65 and older and those who are at risk of serious illness.

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