While global attention is sharply focussed on the progress of COVID-19 vaccines going through various phases of clinical trials worldwide, some public institutions in India and a private player - Serum Institute of India - are attempting to see if a time-tested tuberculosis vaccine  - Bacillus Calmette Guerin (BCG) vaccine - can control the severity, or even delay or prevent, the novel coronavirus infection.  

The Clinical Trial Registry of India lists at least five clinical trial proposals sponsored by Indian Council of Medical Research (ICMR), Jawaharlal Institute of Post Graduate Medical Education and Research (JIPMER), Maharashtra Medical Education and Drugs Department and Serum Institute of India to see BCG vaccine's impact on COVID infection. One trial, sponsored by ICMR and planned in AIIMS, New Delhi, Sanjay Gandhi Post Graduate Institute of Medical Sciences (SGPGI), Lucknow and  School of Tropical Medicine, Kolkata attempts to see if BCG vaccination in the 18 to 60 year age group reduces the incidence and severity of COVID-19 in the high-risk population. This phase III, multicentric, quadruple blind randomised controlled trial will see 800 volunteers with underlying medical problems like diabetes, kidney and heart ailments getting one dose of BCG vaccine followed by a nine-month observation for its effects.

Yet another trial, again sponsored by ICMR will target healthy elderly people (60 to 95 years) in Delhi, Mumbai, Jodhpur, Bhopal, Chennai and Ahmedabad to evaluate if the BCG vaccine is effective in reducing morbidity and mortality in elderly individuals in COVID-19 hotspots in India. A third one, initiated by JIPMER is a double blind randomised controlled trial that will look at the effect of the vaccine on healthcare workers by enrolling doctors and nurses and housekeeping staff posted to take care of patients in the designated COVID 19 wards / ICUs for at least one shift (minimum six hours) and laboratory staff where SARS-CoV-2 testing is being performed.

The centre is yet to initiate the trial or enroll the volunteers. Meanwhile, Maharasthra government's Haffkine Institute is trying to administer BCG vaccine on COVID patients admitted in the hospital in the 20 to 40 age group in Mumbai to see if it can be a potential therapy for them. The clinical trial of Serum Institute uses Recombinant BCG vaccine and not the conventional vaccine used by other institutions to see if administration of the vaccine can reduce infection incidence and disease severity of SARS-COV-2/COVID-19 among high-risk group of people. It is by far the largest trial with 39 clinical trial sites in the states of Delhi, Maharashtra, Tamil Nadu, Chattisgarh, Uttar Pradesh, Karnataka, West Bengal, Haryana, Gujarat and the Union Territory of Chandigarh carried out a multicenter, Phase III, double-blind, randomised, placebo-controlled study to evaluate the efficacy of Recombinant BCG vaccine.  

Incidentally, India is not the only place where such clinical trials to check the innate immunity of existing vaccines, especially BCG vaccine is being tried. International science and medical journals like Lancet and Nature have published research papers hinting at the possibility of BCG vaccine proving effective against COVID-19. Some have even argued that the low rate of COVID-19 mortality in countries like India could be because of the universal BCG immunisation policies it follows. International trials for assessing BCG as a prophylactic agent against COVID-19 area also underway.  

If BCG is indeed proven to be effective against COVID, India will gain on multiple counts. First of all, it can initiate the administration of a dose of BCG on adults without any safety concerns. Secondly, India can use its already existing capacity to produce the vaccine in bulk, without any foreign dependence within no time.  

If COVID-19 vaccines get approved by the time BCG trials are over, we will still have a cost-effective extra protection available.