Why in news?
Doctors and scientists in India have expressed caution on a study, which argues that countries that have deployed the BCG-tuberculosis vaccine in their immunisation programmes have seen fewer deaths from coronavirus (COVID-19).
What the Study showed?
Note: The study, that hasn’t been peer-reviewed, but is available for public scrutiny.
- The Study argues that 55 middle and high-income countries chosen for the analysis, that have a current universal BCG policy had 0.78 deaths per million people, whereas middle and high income countries that never had a universal BCG policy (5 countries) had a larger mortality rate, with 16.39 deaths per million people, a significant variation.
- Low and middle-income countries, even if they had universal immunisation policies, were excluded from the analysis because they were also likely to have low testing rates for COVID-19 infection and therefore fewer reported deaths.
- India, while having a universal BCG policy in place and relatively fewer deaths as a proportion of confirmed coronavirus infections, wasn’t included in the analysis. Many experts say that India tests relatively too little.
- The BCG vaccine is known to confer a strong immune response that had protective effects beyond just staving off a tuberculosis infection and because COVID-19 was particularly lethal to the elderly, those countries where the elderly were likely to have had a BCG shot in their childhood were likely to be better protected against coronavirus – says the study.
What can be relied upon for now?
- Only actual data that showed people who’d been immunised and showed less disease would be convincing.
- Australia, the Netherlands, the United States are going to vaccinate healthcare workers with BCG, so the results from that would be good evidence.
- However, several studies over the years have shown that the BCG vaccine, because it accentuates a powerful immune response, has conferred a significant degree of protection against leprosy and non-invasive bladder cancers.
What is BCG Vaccine?
- Bacillus Calmette–Guérin (BCG) vaccine is a vaccine primarily used against tuberculosis (TB).
- In countries where tuberculosis or leprosy is common, one dose is recommended in healthy babies as close to the time of birth as possible.
- In areas where tuberculosis is not common, only children at high risk are typically immunized, while suspected cases of tuberculosis are individually tested for and treated.
- Adults who do not have tuberculosis and have not been previously immunized but are frequently exposed may be immunized as well.
- BCG also has some effectiveness against Buruli ulcer infection and other nontuberculous mycobacteria infections.
- Additionally it is sometimes used as part of the treatment of bladder cancer.
- India and Pakistan introduced BCG mass immunization in 1948, the first countries outside Europe to do so.