Yet another study has established that BCG (Bacille Calmette-Guerin) vaccine increases the ability of the immune system to fight off Coronavirus disease (Covid-19).

According the preprint study available on medRxiv, an open access server for health sciences, some staff members of the Emirates International Hospital in United Arab Emirates was administered a booster BCG vaccine at the beginning of March. By the end of June, the hospital staff was tested for Covid-19 using the reverse transcription polymerase chain reaction (RT-PCR) test.

The participants were divided into two groups: booster vaccinated, and unvaccinated members.“…Results: 71 subjects received the booster vaccination. This group had zero cases of positive Covid -19 infection. 209 subjects did not receive the vaccination, with 18 positive PCR confirmed Covid -19 cases. The infection rate in the unvaccinated group was 8.6% versus zero in the booster vaccinated group…,” says the research paper that has not yet been peer reviewed.

“Our findings demonstrated the potential effectiveness of the booster BCG vaccine, specifically the booster in preventing Covid-19 infections in an elevated-risk healthcare population,”the paper adds.

This is at least the fifth study to show the possible benefits of the BCG vaccine, which has been administred to most Indian children for decades.

BCG protects against childhood tuberculosis (TB) in countries such as India, where it is administered to newborn babies as part of the immunisation programme.

India’s low Covid-19 case load has been partly attributed to BCG vaccination that is a part of the National immunisation programme for about 50 years.

India is conducting its own study on the vaccine’s efficacy.

“One of the reasons for low mortality due to Covid-19 in India is said to be the BCG vaccine which is being given at birth to all children since 1962-63. ICMR study is to establish that and is being conducted among elderly population. AIIMS, Delhi, is one of the trial sites. The work has started and ethics committee clearance is also in place. The vaccine will be given on OPD basis especially in people from hotspot areas,” said Dr AB Dey, head, geriatrics department, AIIMS, Delhi.

The Indian Council of Medical Research- National Institute for Research in Tuberculosis (ICMR- NIRT) has initiated a multi-centric study to see if BCG can reduce the severity of Covid-19 among individuals aged 60 years and above residing in hotspots.

About 1000 healthy volunteers above 60-years of age are being recruited in six states with high Covid-19 disease burden, and will be followed up for six months.“The process has begun at NIRT, which is identified the nodal institute to spearhead the study. It is too early to comment on the results, but we will share information when there is an update,” said Dr Rajnikant Srivastava, spokesperson, ICMR.

The states where the study has been planned are Tamil Nadu, Maharashtra, Gujarat, Madhya Pradesh, Rajasthan and Delhi.

The researchers of the medRxiv study, however, do acknowledge there were certain limitations that could somewhat impact the results.

“…such as lack of clear understanding and documentation of any confounding factors between the two groups that could have influenced the transmission and infection rate, sample size, and discrepancy between the number of subjects in the two groups. Staff comorbidity as well as any over the counter supplements that the staff could have taken in attempts to prevent Covid-19 infection was not documented. Despite the limitations of this study, we feel that our findings of 8.6% versus zero percent infection rate is significant enough to suggest the promising effectiveness of an up-to-date BCG booster vaccine in prevention of Covid19 infection,” they said in the paper.