HealthNovavax coronavirus vaccine found 89 per cent effective in trials Clinical trials show that a new covid-19 vaccine developed by Novavax is highly effective against a variant of the coronavirus vaccine circulating widely in the UK, but less effective against a variant in South Africa 51¶¯Âþ
HealthCovid-19 outbreak in Manaus suggests herd immunity may not be possible Though 76 per cent of people in Manaus, Brazil have covid-19 antibodies, the virus is spreading quickly – potentially fuelled by a new variant – which may mean herd immunity by infection is not possible 51¶¯Âþ