Scientists are investigating the possible benefits of BCG vaccination in the fight against coronavirus
The BCG benefit assumption may explain the low mortality rate in some poor countries.
A team of scientists from the New York University of Technology reported that mortality from Covid-19 infection is inversely correlated with the prevalence of tuberculosis vaccination (BCG vaccine).
According to Naked Science, this article is posted in the MedRxiv preprint archive.
Researchers have drawn attention to different patterns of the COVID-19 pandemic in different countries. In the paper, they hypothesize that differences can be influenced, among other things, by national BCG vaccine policies.
It is noted that BCG is an inexpensive and safe anti-tuberculosis vaccine made from a weakened strain of live bacteria Mycobacterium Bovis, which has proven effectiveness in the fight against other diseases caused by mycobacteria: in particular, with leprosy and ulcer Buruli.
According to American scientists, BCG vaccination gives the body some benefits in the fight against COVID-19. Comparing anti-TB vaccination policies in different countries, researchers found that countries without a universal vaccination policy (such as the Netherlands, Italy, and the United States) are much more affected by the pandemic than those countries where such a vaccine is used long and regularly.
Among the latter, researchers mention Brazil, where general tuberculosis vaccination has been used since 1920, and Japan: BCG has been widely used there since the late 1940s. However, states where universal vaccination policies were formed relatively recently (for example, Iran, where widespread BCG use began only in 1984), have an especially high mortality rate among the elderly.
The assumption made in the article may explain the low mortality rate in some poor countries – for example, in the post-Soviet space and in Eastern Europe.
However, the authors took into account the fact that this may be due to poor quality of diagnosis or deliberate underestimation of statistics, so excluded such “anomalies” from their study.
The definitive conclusion about the effectiveness of the BCG vaccine is too early to make. First, the article has not yet been reviewed and has not been accepted by any reputable scholarly publication. Secondly, clinical trials need to be conducted to confirm the effectiveness of the anti-TB vaccine. Such research is now being conducted by scientists at the Murdoch Children’s Research Institute in Melbourne.
Possible biochemical mechanisms for the protection of the BCG vaccine against coronavirus have also not been determined.
The work of US researchers also does not explain why the correlation between ubiquitous BCG vaccination and reduced coronavirus mortality has not been observed in China, where universal immunization has long been used. Many scientists have questioned the fact that vaccinations made as a child can help older people get the disease. Tuberculosis protection is fully effective for 10-15 years, and its efficacy is not well-defined at the end of this term.
Source: unian.ua
