Experts argue COVID-19 vaccine boosters should be delayed
A new article published in The Lancet is arguing against broadly administering COVID-19 vaccine booster shots at this point in time. The article is co-authored by two of the US Food and Drug Administration’s top vaccine advisors, both of whom recently announced they were stepping down from their positions.
The succinct but thorough review article outlines the evidence for COVID-19 vaccine booster shots. The article explains there may be a need for vulnerable and immunocompromised populations to receive a third vaccine dose right now, but in otherwise healthy individuals the data currently indicates vaccines remain highly protective against severe COVID-19.
“Current evidence does not, therefore, appear to show a need for boosting in the general population, in which efficacy against severe disease remains high,” the article states. “Even if humoral immunity appears to wane, reductions in neutralizing antibody titre do not necessarily predict reductions in vaccine efficacy over time, and reductions in vaccine efficacy against mild disease do not necessarily predict reductions in the (typically higher) efficacy against severe disease.”
The review article is authored by a large international team, including researchers from the University of Oxford and the World Health Organization. But two specific co-authors on the article are generating the most attention – Philip Krause and Marion Gruber.
Krause and Gruber, director and deputy director of the FDA’s Office of Vaccines Research & Review, both controversially announced they were stepping down from their positions two weeks ago. Between them they have decades of experience regulating and reviewing vaccine safety at the FDA.
Their unexpected resignations came soon after the US government made a formal announcement for a broad COVID-19 vaccine booster program commencing in late September. The unusual booster announcement preceded any formal decisions made by the FDA or CDC, and it has been reported this played a notable role in Krause and Gruber’s ultimate decision to step down.
The new review article in The Lancet summarizes the current booster debate, which hinges on growing evidence showing vaccine effectiveness waning against mild symptomatic disease. Current data indicates vaccines are still profoundly effective at protecting individuals from severe COVID-19, hospitalization and death up to six months after immunization.
However, increasing numbers of mild breakthrough infections are being observed, particularly in relation to the now dominant Delta variant. Instead of deploying booster programs right now, the article argues the focus should be on getting more unvaccinated individuals immunized. The article also argues for the development of variant-specific boosters to be administered if, or when, current vaccine protection from severe disease begins to wane.
“Although vaccines are less effective against asymptomatic disease or against transmission than against severe disease, even in populations with fairly high vaccination rates the unvaccinated are still the major drivers of transmission and are themselves at the highest risk of serious disease,” the article states. “The effectiveness of boosting against the main variants now circulating and against even newer variants could be greater and longer lived if the booster vaccine antigen is devised to match the main circulating variants. There is an opportunity now to study variant-based boosters before there is widespread need for them.”
The FDA's Vaccines and Related Biological Products Advisory Committee is set to meet this coming Friday, September the 17th. Here they will decide on whether or not to recommend the booster program previously announced by the White House.
Ahead of the FDA meeting later this week new research is set to be published in The New England Journal of Medicine offering the first real-world data on COVID-19 vaccine boosters from Israel’s recent landmark third dose program. The research, previously published on a pre-print server, indicates a third vaccine dose can significantly reduce risk of COVID-19 infection and also reduce risk of severe disease.
Lead author on the new Lancet review article, Ana-Maria Henao-Restrepo, a researcher working with the World Health Organization, says the primary goal of vaccination is to prevent severe disease. And she says current vaccine supplies should be used to fulfill that primary goal, reiterating recent calls from the WHO for countries with high vaccination rates to hold off on administering booster shots until the end of the year.
“The limited supply of these vaccines will save the most lives if made available to people who are at appreciable risk of serious disease and have not yet received any vaccine,” says Henao-Restrepo. “Even if some gain can ultimately be obtained from boosting, it will not outweigh the benefits of providing initial protection to the unvaccinated. If vaccines are deployed where they would do the most good, they could hasten the end of the pandemic by inhibiting further evolution of variants.”
The new review article is published in The Lancet.
Source: The Lancet