Pretoria, June 26 (RHC)-- Volunteers in South Africa and Brazil have begun receiving injections of a potential vaccine against the coronavirus rolled out by Oxford University. 

The vaccine, developed together with pharmaceutical group AstraZeneca, is one of the most promising of the dozens that researchers worldwide are racing to test and bring to market. 

In South Africa, the trial will consist of 2,000 volunteers from 18 to 65 years of age, including some HIV positive patients, who will be monitored for 12 months after vaccination to assess how well the vaccine guards against COVID-19.  

Researchers in Brazil also began administering the vaccine -- known as ChAdOx1 nCoV-19 -- to health workers who are more likely to get infected, said the Federal University of Sao Paulo, which is coordinating the study.