Covid booster effectiveness wanes after 4 months, CDC study shows
A health worker administers a Covid-19 vaccine dose. Although protection decreases with time, a booster shot is still highly effective at preventing moderate and severe illness as well as hospitalisation. PHOTO | FILE | NMG
Booster shots of the Pfizer-BioNTech and Moderna vaccines lose substantial effectiveness after about four months, but still provide significant protection against hospitalisation, a new study has shown.
In the first study on the effectiveness of third dose of mRNA vaccines, results show that immunity against severe Covid-19 disease begins to wane after four months.
