The effectiveness of COVID-19 vaccines dropped dramatically after six months, according to a large study. The new study of U.S. military veterans found that vaccine efficacy against COVID-19 infection plummeted as much as 73% in six months.
The study – published in the journal Science – found that protection from COVID-19 infection provided by the three vaccines approved in the U.S. fell from 87.9% in February to 48.1% in October.
The study examined data from the Veterans Health Administration of 498,148 fully vaccinated veterans. Moderna’s two-dose COVID-19 vaccine went from being 89% effective in March to 58% effective in September. The Pfizer/BioNTech vaccine had an 87% efficacy against coronavirus in March and dropped to only 45% in September. In the same six-month period, the Johnson & Johnson vaccine plummeted from 86% effectiveness to a mere 13%.
