The BCG vaccine does not protect frail older persons from contracting Covid-19. Medical researchers among whom Mihai Neta of Radboudumc, have come to this (preliminary) conclusion in a study among more than 6000 patients of age 60 and over.

The scientists had hoped that the BCG vaccination would also protect against Covid-19, aside from tuberculosis (for which it is actually intended). Such additional protection has previously been observed for other diseases such as yellow fever. The proposed mechanism behind this is that the BCG vaccine would boost the innate immune system.

This appears not to be the case for Covid-19, at least for frail older people. In the study, participants who received a shot with the BCG vaccine, had Covid-19 infections and symptoms just as often as a placebo group without a vaccination. A total of 6132 patients aged 60 years and older (from a total of twenty hospitals) participated in this so-called randomized, double-blind study. This is the ‘gold standard’ in medical research, which makes the results reliable.

Serious disease symptoms

The researchers are still analyzing whether the vaccine prevents serious symptoms of disease. ‘We will analyze that data in the coming weeks’, Netea says in a response. An official publication of the results is yet to follow, but the main findings have already been released due to the clinical implications for patients, according to the press release from UMC Utrecht, which led the study together with Radboudumc.

In addition to this so-called BCG-PRIME study, also several other studies are being conducted into the possible protective effect of the BCG vaccine at the moment, such as among healthcare workers. It could be that the vaccine does offer protection in this group, because the participants are younger and healthier.