World
Johnson & Johnson’s single-dose vaccine 66% effective
Johnson & Johnson said on Friday that its single-dose vaccine was 66% effective in preventing Covid-19 in a large trial against multiple variants across three continents.
In the trial of nearly 44,000 volunteers, the level of protection against moderate and severe COVID-19 varied from 72 per cent in the United States, to 66 per cent in Latin America and just 57 per cent in South Africa, from where a worrying variant has spread.
A high bar has been set by two authorized vaccines from Pfizer/BioNTech and Moderna, which were around 95 per cent effective in preventing symptomatic illness in pivotal trials when given in two doses.
Those trials, however, were conducted mainly in the United States and before new variants emerged.
