Johnson & Johnson’s long-awaited vaccine appears to protect against Covid-19 with just one shot – not as strong as some two-shot rivals but still potentially helpful for a world in dire need of more doses.
J&J said on Friday that in the US and seven other countries, the single-shot vaccine was 66 per cent effective overall at preventing moderate to severe illness, and much more protective – 85 per cent – against the most serious symptoms.
There was some geographic variation. The vaccine worked better in the US – 72 per cent effective against moderate to severe Covid-19 – compared to 57 per cent in South Africa, where it was up against an easier-to-spread mutated virus.
“Gambling on one dose was certainly worthwhile,” Dr Mathai Mammen, global research chief for J&J’s Janssen Pharmaceutical unit, said.