Pfizer Inc and BioNTech SE have asked the US health regulator to relax requirements for their COVID-19 vaccine to be stored at ultra-low temperatures.

South Africa was ravaged by a second wave caused by a more contagious variant that has jammed up casualty wards

A laboratory study suggests that the South African variant of the coronavirus may reduce antibody protection from the Pfizer Inc/BioNTech SE vaccine.

These findings were also similar to the first-dose efficacy of 92.1% reported for Moderna Inc's mRNA-1273 vaccine

Britain on Wednesday became the first country in the world to allow volunteers to be exposed to the COVID-19 virus.

The World Health Organization has alerted six countries to watch out for potential Ebola cases.