Americans should receive COVID-19 booster shots to “maximize vaccine-induced protection,” a group of top U.S. health officials said Wednesday. The decision follows an analysis of new data by U.S. health officials, who believe protection may diminish over time, enough to warrant a booster.
According to The New York Times, the Centers for Disease Control and Prevention’s (CDC) data released on Wednesday shows that, while “the vaccines remain highly effective against hospitalizations, the bulwark they provide against infection with the virus has weakened” over the past few months. Stat News, a medical news website, reports that the U.S. health officials pointed to data showing that the Pfizer and Moderna vaccines were “no longer protecting as well against mild and moderate Covid-19 infections as evidence that ‘could’ signal a decline in protection against serious disease.”
It’s not exactly clear from the data, however, why vaccine efficacy would be dropping. The Times notes that the drop could be “the result of waning immunity, a drop in precautions like wearing masks, or the rise of the highly contagious Delta variant.” According to The Washington Post, officials have pointed to a loss of efficacy over time and to the spread of the Delta variant, which now accounts for more than 98% of sequenced U.S. COVID-19 cases.
The group of health officials, which includes CDC Director Dr. Rochelle Walensky and Dr. Anthony Fauci, said they are prepared to offer boosters to “all Americans” beginning the week of September 20, if boosters receive FDA recommendation. The boosters would be given 8 months after a second dose.