What does this mean for SA, where the BCG vaccine has been mandatory for several decades?
According to Prof Greg Hussey, who leads Vaccines for Africa at the University of Cape Town (UCT), the vaccine first came about in 1921 and was distributed to “a number of laboratories worldwide”.
Different forms of the vaccine were then created, and evidence emerged suggesting that BCG vaccinations for newborns could improve general protection against certain respiratory infections by the mechanism of “trained immunity” (meaning the immune system is “trained” by the vaccine to recognise a respiratory infection later in life and respond more quickly as a result).
What we do know is that the BCG vaccine can provide protection against diseases that it doesn’t specifically target.
In SA, it was first used in the early 1950s, but Hussey said it was “sporadic” at that time and given to schoolgoing children. This means if you were born in the 1940s or earlier, there is a small chance you were vaccinated, but it is not a given.
It was “only from 1973 that BCG has been given universally to all newborn infants, with very high coverage in SA”.
Therefore, said Hussey, only adults in their mid-40s and younger could say they probably received the BCG vaccine. These will include large numbers of our health workforce, while those between 47 and 65 years old “possibly received BCG”.
However, it is “unlikely that those older than 65 years received the BCG vaccine”.
Furthermore, said clinicians and epidemiologists, it may flatten the Covid-19 curve but does not prevent the pandemic from spreading like wildfire.
SA has recorded more than 520,00 Covid-19 cases, and the official death toll is close to 9,000.