Another boost for Pfizer and Biontech
Data are in from the first randomised, controlled Covid-19 vaccine booster trial, from Pfizer and Biontech, and the topline efficacy has come out at an excellent 95.6%. All 10,000 patients in the phase 3 trial had been fully vaccinated with Comirnaty; around 11 months later half received a third shot of the vaccine and half placebo. Only five of those given the booster jab came down with the virus, whereas there were 109 cases in the placebo group. But the 95.6% figure was measured only in those patients who had not previously had Covid-19, the population analysed for just one of the co-primary endpoints. The other primary efficacy measure concerns Covid-19 incidence among participants with and without evidence of past infection. On this measure Pfizer and its partner are, so far, silent. Also missing from the release was any information on severe disease, hospitalisation or death. The FDA authorised a booster dose of Comirnaty a month ago for old and high-risk people, and yesterday it permitted mix-and-match regimes. Pfizer and Biontech have been winning the rollout so far, and seem likely to lead the booster effort too.