Another booster shot of the Pfizer-BioNTech Covid vaccine provides additional short-term protection against oomerican infection and severe illness in older adults, according to a new Israeli study.
But the booster effect against the infection usually subsides after only four weeks and disappears after about eight weeks. The protection against acute illness did not decrease at six weeks after the additional dose, but the follow-up period was short enough to determine whether another booster provided better long-term protection against severe disease than single booster. General Chat Chat Lounge
The study focused on adults 60 years of age and older, and did not provide data on the effectiveness of second boosters in the young population.
The results, published on Tuesday in the New England Journal of Madison, suggest that additional advances are likely to provide immediate protection against Omicron infection in older recipients, and consistent with evidence suggesting the effectiveness of vaccine against infection faster. Becomes worse against severe illness.
“For confirmed infections, the fourth dose appears to provide only short-term protection and a modest absolute benefit,” the researchers wrote.
The result comes in the middle of a debate about what and when Americans need extra boosters. The Food and Drug Administration is bringing together a panel of outside consultants on Wednesday to discuss the US-wide booster strategy.
The rapid transfer of the rapidly-spreading oomericone type, which can withstand some of the body’s immune defenses, has sparked debate about whether second boosters are widely needed.
Last month, the FDA approved booster shots of both the Pfizer-BioNTech and Moderna vaccines for adults 50 and older, as well as the immune system for people 12 and older. The agency also adopted an mRNA booster for adults who have already received two doses of Johnson & Johnson’s vaccine.
This is likely to be a hard sell: while 66% of Americans have been vaccinated, only 30% have received a booster shot.
It is clear that the Omicron variant has eliminated the effectiveness of Covid vaccines, but data on the benefits of both boosters is limited. An earlier study from Israel, which has not yet been published in a scientific journal, found that older adults who received a second booster were 78 percent less likely to die of cod-19 than they were. Who had just received a booster shot.
But scientists have criticized the method of study, and the benefits of a second booster for young, healthy adults are less clear. Some experts note that most adults who have been vaccinated and once vaccinated are already more likely to be protected from serious illness and death.
On January 2, Israel adopted the fourth dose of the Pfizer-BioNTech vaccine for adults 60 years and older and for members of other high-risk populations who received at least four months before the third shot. Israel’s vaccination campaign relies heavily on the Pfizer-BioNTech vaccine.
The new study taxes the Israeli Ministry of Health’s record on more than 1.2 million older adults who were eligible for a fourth shot between January 10 and March 2, when Omicron was the dominant type in the country.
Researchers compared the confirmed virus infection rate and severe Covid-19 cases with those who received only the fourth dose among those who received the fourth dose.
Protection against infection appeared at the peak four weeks after the fourth shot: the confirmed infection rate was twice as high in the three dose group as in the four dose group. For the first eight weeks after the fourth shot, however, additional protection against the infection had almost disappeared, the researchers found.
Four weeks after the booster shot, the severe disease rate was 3.5 times higher in the three dose group compared to the four dose group, the researchers found. This protection did not appear to be abolished and actually increased slightly after six weeks post-shot, when the rate of severe disease was 4.3 times higher in the three-dose group.
But the studies cover a relatively short period, and whether the benefits of the disease have long-term benefits is unknown. The study did not report data on death.