AstraZeneca vaccine gets positive US trial results

The US phase III trial of AZD1222, developed with Oxford University, showed 79% vaccine efficiency in preventing Covid-19 and 100% efficacy at preventing severe disease and hospitalisation, the company said.

Vaccine efficacy was consistent across ethnicity and age. Vaccine was 80% in participants aged 65 and over - an improved finding compared with other tests. An independent board found no safety concerns related to the vaccine.

The board found no increased risk of thrombosis or thrombosis-linked events among the 21,583 participants who received at least one dose of the vaccine and no cerebral venous sinus thrombosis incidents.

AstraZeneca's vaccine has faced scepticism in Europe after a small number of recipients were found to have blood clots, prompting more than a dozen countries to suspend its use. Politicians such as France's Emmanuel Macron questioned its effectiveness in older people.

On Friday the European Medicines Agency concluded the jab, the most easily produced and transported vaccine so far, was "safe and effective". AstraZeneca said on Monday the US results underlined its vaccine was "well tolerated and highly effective" in all groups.

Ann Falsey, co-lead principal investigator for the trial, said: "These findings reconfirm previous results observed in AZD1222 trials across all adult populations but it's exciting to see similar efficacy results in people over 65 for the first time. This analysis validates the AstraZeneca Covid-19 vaccine as a much-needed additional vaccination option, offering confidence that adults of all ages can benefit from protection against the virus."