AstraZeneca vaccine 100pc effective against severe Covid

WASHINGTON: The Oxford/AstraZeneca vaccine is 79 per cent effective at preventing Covid-19 and offers 100 per cent protection against severe disease, new data from a US-led trial has shown.

The jab, which has been the subject of controversy in Europe over concerns about links to very rare blood clots, is also 100 per cent effective at keeping people out of hospital with severe illness.

Some 32,449 people across all age groups took part in the phase three trial in the US, Chile and Peru, with a total of 141 cases of symptomatic Covid-19 reported.The results showed that among people aged 65 and over, there was 80 per cent protection against developing Covid-19. The degree of effectiveness against symptomatic Covid-19 was even higher than observed in the Oxford-led clinical trials.

An independent data safety monitoring board (DSMB) also identified no safety concerns relating to the vaccine. It conducted a specific review of thrombotic events, as well as cerebral venous sinus thrombosis (CVST) – the specific type of brain blood clot that has been troubling Europe.

The DSMB found no increased risk of thrombosis among the 21,583 participants receiving at least one dose of the vaccine. The specific search for CVST found no cases in this trial.