A new report in The Lancet medical journal claims that vaccines are effective enough at preventing severe COVID-19 that there is no current need for the general population to be given third doses.
Some countries, including Israel, have started offering booster shots over fears about the much more contagious Delta variant, causing the World Health Organization to call for a moratorium on third shots amid concerns about vaccine supplies to poorer nations, where millions have yet to receive their first.
But the Lancet report concludes that even with the threat of Delta, “booster doses for the general population are not appropriate at this stage in the pandemic.”
The authors, who reviewed observational studies and clinical trials, found that vaccines remain highly effective against severe symptoms of COVID-19, across all the main virus variants including Delta, although they had lower success in preventing asymptomatic disease.
“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,” says lead author Ana-Maria Henao-Restrepo, of the WHO.
The authors of the study argue that the current variants had not developed sufficiently to escape the immune response provided by vaccines currently in use, and if new virus mutations did emerge that were able to evade this response, it would be better to deliver specially modified vaccine boosters aimed at newer variants rather than those based on the existing vaccines.