No proof yet that BCG benefits against coronavirus, says expert

Prof Madhukar Pai, Canada Research Chair in Epidemiology & Global Health

Prof Madhukar Pai, Canada Research Chair in Epidemiology & Global Health   | Photo Credit: Special Arrangement

Madhukar Pai, is Canada Research Chair in Epidemiology & Global Health and Director, McGill Global Health Programs and Professor at McGill University. In an email interview to The Hindu, he explains the debate on BCG vaccine’s purported effectiveness against COVID-19 and how global approaches to communicable diseases might change.

You have advised against over optimism with regards to the link between BCG and COVID-19 immunity. What are your reasons?

As a tuberculosis (TB) researcher who was born in India, I would be thrilled if BCG worked against COVID-19. It is a cheap, readily available, safe vaccine. But we are not there yet. Currently, what we have are a few ecological studies (not peer-reviewed) which take country-level BCG and COVID-19 data, and report a correlation that countries that give BCG to children have a lower rates of COVID-19 cases and deaths. Based on this early signal and based on our prior knowledge that BCG does have non-specific immune-boosting properties, it is perfectly fine to conduct trials to confirm the hypothesis. Indeed, such trials are starting in the U.S., Netherlands and Australia. I welcome that.


But the current ecological evidence is far from sufficient for any immediate public health or clinical use during this crisis. Ecological studies offer a very weak level of evidence because correlations that are true at the country level might not hold true at the individual level. For example, we know not everyone who lives in a low-income country is poor — some individuals are very rich. Same logic applies to ecological comparisons. In addition, ecological studies have been done at a time when the epidemic is exploding in many low/middle income countries. Repeating the studies in a month might produce different results. We also know many low/middle income countries, including India, are seriously under-testing for COVID-19. Lastly, there is also bias due to confounding – countries that give BCG are mostly in Asia, Africa and Latin America, with much younger populations than Europe or North America.

I understand everyone is desperate for some good news, but we cannot abandon good science. So, until trial results are out, countries like India must focus on interventions such as largescale testing, isolation, contact-tracing, and physical distancing (where feasible). During lockdown, the most vulnerable, poorest people must receive cash and social benefits. India should also ensure personal protection equipment to all healthcare care providers and strengthen hospital capacity to deal with severely ill patients. It would be dangerous for policy-makers to assume protection from BCG and not act. That is why I am worried about all the media hype.

TB continues to kill thousands of people in India. How might coronavirus affect TB services in India and what can be done about that?

This is my biggest worry – even without COVID-19, TB kills 1,000 Indians every day. No country has more TB patients than India. And now, with the lockdown, things are going to get much worse. Already, there are preliminary reports of a 80% decline in TB case notifications. People on TB treatment are struggling to get their medicines on time, and people with new TB symptoms are unable to access medical care. TB patients and survivors often have lung damage and if they got COVID-19, they could be at higher risk of complications. I worry about an increase in TB mortality in the coming months, and that will be so sad. There is also the risk of running out of anti-TB medicines, since India relies heavily on China for raw materials.

What can be done to avert this disaster? Right now, all known TB patients could be supported via remote or tele-consultations using call centres, or other digital technologies. Drugs could be sent to their homes via couriers or through local pharmacies (that are still open). For any new TB patient, TB medicines could be given for a longer duration (e.g. 2 or 3 months) to ensure they have enough. India could work with generic drug companies and proactively plan for increasing anti-TB drug production to make sure stocks don’t run out in a few months. If the public sector gets overwhelmed with COVID-19, this crisis is a good opportunity for the private health sector to pitch in and take care of TB patients.

Has the TB programme lessons for the COVID-19 response? Or vice versa?


Yes, TB programmes are known for public health interventions such as active case finding, contact investigations, respiratory isolation, and community-based patient support. These skills and expertise could be leveraged to tackle COVID-19. Also, some of the existing TB technologies could come in handy. For example, India has two molecular technologies in use (GeneXpert by Cepheid and TrueNat by Molbio) that are used for TB testing and both can now be used to test for COVID-19. India is already using digital adherence technologies such as 99DOTS and Everwell Hub and these could be repurposed to also work for COVID-19.

India has shown great commitment to tackling COVID-19 in a short period of time. I wish some of that commitment will also be shown to tackling TB, which has killed millions of Indians over the years. Historically, TB control has received little political attention, funding or popular support. After the pandemic, the Indian National TB elimination programme will need a lot more funding than they have now. I hope existing TB funding will not be diverted towards COVID-19. That would be disastrous.

How can a country prepare for a pandemic?

I don’t think any country in the world was adequately prepared for COVID-19. Even the richest countries in the world are struggling right now. A big lesson for India and many other countries is that no country can prepare for a crisis within days or weeks. Being prepared means having a robust healthcare system, especially primary healthcare. In short, universal health coverage is a pre-requisite for real preparedness.

We know India has failed to invest in health for decades, barely spending 1.5% of the GDP on health. Even the bare minimum recommended health spend of 2.5% of GDP has not been realised. This chronic under-investment has left the public health system weak, and has allowed the private and informal health sectors to thrive. This means, access to healthcare is not equitable – the rich and the middle class will manage, but what happens to the millions below the poverty line?

If any good comes out of this crisis, then it will be India waking up to the reality that investing in health is paramount for economic growth and security. Ignoring health, we have now learnt, can cost the economy in trillions. India absolutely must invest at least 2.5% of the GDP on health, and strengthen the primary health system. If not, the next pandemic will be even worse. India must also better regulate and govern the large private health sector and make sure it works for the country.

How do you think COVID-19 will/should change global policy approach towards communicable diseases?

COVID-19 will change global health in many ways. The optimist in me hopes all countries will learn from the pandemic and invest in universal health coverage and re-affirm health as a human right. Global health must be more than just fighting one epidemic after another. I hope investments in public health and developmental assistance will no longer be viewed as a drain on resources. I hope countries will understand the need to build a social safety net for all.

The pessimist in me fears that the economic losses will force rich countries to scale back on international aid. India will need to be self-reliant and it is making progress towards that. But if COVID-19 depletes India’s economy, I really worry that India will spend even less on health, despite understanding the critical importance of health during this pandemic.

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Printable version | Sep 24, 2020 9:45:38 PM |

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