Two Covid-19 vaccine candidates have proven safe for humans and produced strong immune reactions among patients involved in two separate clinical trials, doctors said on Monday.
The studies, published in The Lancet medical journal, constitute a major step on the road towards a Covid-19 vaccine that is effective and safe for widespread use.
The Oxford team found that among the 500 or so patients given a single dose of the vaccine – developed jointly with pharmaceutical giant AstraZeneca – their immune response peaked around 14 days and decreased slightly by day 56, the end of the study period.
The second trial, led by China’s Jiangsu Provincial Center for Disease Control and Prevention, used a weakened human cold virus modified to deliver genetic material that teaches cells to recognise the novel coronavirus.
More than 90 per cent of people in both groups showed either antibody or T cell immune responses between 14-28 days post-vaccine.
