BCG Vaccine Can it Prevent COVID-19?

BCG (Bacille-Calmette-Guerin)vaccine which is used in several Asian countries to give protection against tuberculosis and is still recommended by WHO in countries with a high incidence of this disease. There is some evidence that BCG vaccination has nonspecific effects on the immune system, although these effects are not very well characterized by an unknown clinical relevance. There is also some evidence that it gives nonspecific protection against influenza and also reduces the risk of sepsis and hospitalizations for children for causes other than TB.In an attempt to find out the incidence of COVID 19 in countries where the BCG vaccine is still used in neonates routinely versus those countries where it is not used. The observations were that COVID 19 cases were lower in countries with routine vaccination. There could be an element of bias in such ecological studies, the methodology used, and the testing rates.

Currently, there is no peer-reviewed scientific evidence that BCG vaccination protects people against COVID-19. However, the concept is being tested in two large trials that have begun in Europe, and Australia and WHO would evaluate the evidence when available. In these studies, the BCG vaccine would be given to high-risk health care workers and contacts of patients with COVID.

In contrast in India and South Asia where BCG vaccination in infancy is mandatory, it would be interesting to see the effect of revaccination in boosting their immunity and seeing the effects on getting a COVID 19 infection in a prospective study. Our department at Batra Hospital, New Delhi is participating in this study sponsored by Serum Institute of India and have contributed 50 high-risk individuals with a COVID 19 RT PCR test negative, to begin with. The trial has completed recruitment of 5500 cases in approximately 30 Indian hospitals. The follow up will be for 5 months, during which immunogenicity will be evaluated by antibody response, cytokine assay, and tests to evaluate innate immunity. The results should be available by the year-end. Hopefully, the study would help in blunting the response of COVID-19 in our country, which is currently badly hit.

(The author is a Cardiologist and Scientist, Recipient of Dr. B C Roy award and Padamshri.)

{Prof Upendra Kaul, MD, DM, FCSI, FSCAI, FAPSIC, FACC, FAMS

Awarded Padmashiri and Dr B C Roy Award

Chairman Cardiology and Dean Academics and Research

Batra Hospital and Medical Research Center}