How advanced are COVID booster vaccines?

With ATAGI flagging that third doses and booster shots could soon be used to further protect against COVID, newsGP assesses preliminary results from Moderna and Pfizer’s ongoing clinical trials. Questions regarding vaccine-induced immunity and booster shots have become particularly pertinent following the emergence of new variants of concern. Reports from overseas indicate there is some reduction in long-term protection against symptomatic disease caused by the Delta variant, particularly among older cohorts. These real-world experiences are also being increasingly supported by new studies, such as a recently published interim analysis of Moderna’s vaccine, which reports that the neutralising antibody response for variants such as Beta, Gamma and Delta can be so low that they are undetectable. And while existing COVID strains are already proving challenging to contain, epidemiologists have predicted it is only a matter of time before yet another variant of concern emerges that further limits the efficacy of currently available vaccines. But there is...