Waiting for the fourth dose

Israel was the first country to introduce the fourth dose, announcing in December that adults 60 years of age and older, medical workers, and people with weakened immune systems were eligible if at least four months had passed since the third dose was given. doses. Recently, the Swedish Public Health Agency announced that a second booster dose is recommended for all people aged 80 and over.

In the United States, in turn, health experts emphasized at the end of last year that the fourth dose was not yet needed and decided that it was too early to discuss giving it to most social groups. Now the US Food and Drug Administration is analyzing data on the pandemic and virus variants at home and abroad to assess the potential efficacy and composition of booster doses. As Dr. Peter Marks, director of the FDA's Center for Biological Assessment and Research, emphasized, there is still a lot of uncertainty about the further development of the pandemic, and again the autumn period may turn out to be decisive.

The United States has recently seen significant improvements in the number of recorded COVID-19 cases, hospitalizations and deaths. According to data from Johns Hopkins University, the number of cases fell by 44% on Friday. Compared to the previous week, hospitalizations fell by 26% and deaths by 13%. "Vaccination and supplemental doses will be critical to maintaining this downward trend, especially when it comes to severe disease leading to hospitalization," said Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases.

Meanwhile, drug makers continue to study the effects of the fourth dose of the vaccine in wider populations. Pfizer announced in January that it was investigating the safety and effectiveness of a second booster dose in an ongoing study in healthy adults aged 18 to 55 years. “Recent studies show that booster doses continue to provide a high level of protection against hospitalization for Omicron infection. We understand that you need to be prepared in case this protection wears off over time, ”commented Kathrin Jansen, head of vaccine research and development at Pfizer.

How is vaccine efficacy today in the US, where the dominant Omicron variant is? On average, it is at the level of 78 percent. to the fourth month after the administration of three doses. According to Dr. Fauci, this is still a high level of protection.

Dr. Christopher Murray of the University of Washington said giving a fourth dose now makes little sense, but will likely need to be revived in the fall.
"As Omicron goes away," he said, "the third dose of immunity is waning, so the fourth dose is likely to go away as well. So we'd like to schedule a fourth dose when a new variant becomes available or for next winter. So I guess now, unless you are immunocompromised or older, unless you have some personal risk, it doesn't make much sense. " The timing of the fourth dose depends not only on the decline of immunity, but also on whether more coronavirus variants are visible on the horizon. What really is a problem among local health officials is the fact that the rate of intake of the third dose is slowing down. About 65 percent. of the US population are fully vaccinated with at least the first series, and about 28 percent. of the population received a booster dose (CDC data). Suddenly, it may turn out that a significant proportion of Americans will not be up to date with vaccinations, and failure to do so may again bring up the dark scenarios of previous waves.

Source: CNN