An international group of vaccine experts, including two former US Food and Drug Administration (FDA) officials, said today that scientific evidence doesn’t yet support the broader rollout of COVID-19 boosters.
No drop in protection against severe disease
The group, which also includes experts from the World Health Organization (WHO), based its findings on a review of randomized clinical trials and observational studies. The experts reported their findings today in a Viewpoint piece in The Lancet.
Later this week, FDA advisors will discuss Pfizer-BioNTech’s application for COVID-19 vaccine booster doses, and last week, the head of the WHO pushed for an extension of a moratorium on booster doses until the end of the year to allow more people in low- and middle-income countries to be vaccinated.
In the new Lancet review, the authors said observational studies consistently show that the vaccines are still highly effective against severe disease, including severe disease from all variants, with efficacy averaging 80% against any disease.
Though they note that vaccine efficacy is greater against severe disease than against mild illness, even in highly vaccinated populations, those who are unvaccinated are still the main drivers of transmission and are at most risk for severe disease.
In a Lancet news release, Ana-Maria Henao-Restrepo, MD, senior author and head of the WHO research and development blueprint, said that, taken together, the studies don’t show credible evidence of declining protection against severe disease—vaccination’s main goal.
“Even if some gain can ultimately be obtained from boosting, it will not outweigh the benefits of providing initial protection to the unvaccinated,” she said. “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 experts note one study, however, that shows strong benefit of a booster COVID vaccine dose in Israel. They cite preliminary data posted Aug 27 that show an 11.4-fold decrease in the risk of confirmed infection and a greater than 10-fold decrease in the risk of severe illness 12 are more days after receipt of a booster dose. Israeli officials rolled out booster doses on Aug 1, reaching about 2 million people by month’s end.
The Lancet authors say more long-term Israeli booster-dose data are needed. The study from the Israeli team with more complete data is slated to be published this week.
More global headlines
- In China, an outbreak in the Fujian province city of Putian—home to 2.3 million people—has resulted in a partial closure and other COVID restrictions, according to Reuters. The country reported 42 local cases from the province over the last few days.
- Elsewhere in Asia, Vietnamese officials extended restrictions in the country’s Ho Chi Minh City hot spot until the end of September, and South Korea is transitioning to a more relaxed COVID-19 response by allowing more people with milder infections to recover at home.
- Australia on Sep 11 reported a record daily high of more than 2,000 cases, as officials in Queensland state considered a circuit-breaker lockdown after a family cluster of cases was detected in Brisbane.
- The global total today climbed to 225,014,163 cases, and 4,635,805 people have died from their infections, according to the Johns Hopkins online dashboard.