Coronavirus | India can expect around 1.3 billion doses of vaccines, says epidemiologist Chandrakant Lahariya

Dr. Lahariya counters figure projected by government.

Updated - December 04, 2021 10:30 pm IST

Published - May 21, 2021 06:08 pm IST

A tribal head taking the vaccine at Anaikatti village in Nilgiris district, Tamil Nadu. File photo

A tribal head taking the vaccine at Anaikatti village in Nilgiris district, Tamil Nadu. File photo

India ought to realistically expect around a 1.3 billion doses of vaccines from August to December and not the 2 billion that the Centre has projected , said epidemiologist, public health expert and author Dr. Chandrakant Lahariya, in an interview to The Hindu .

The estimate that had been made by Dr. V.K. Paul, who heads India’s COVID-19 task force, is premised on vaccines from eight companies. Four of those vaccines (Biological E, Zydus Cadila, Genova Biopharma and Bharat Biotech Nasal) are in various phases of clinical trials, some in phase 1-2, said Dr. Lahariya and their success and eventual licensing could not be predetermined.

Dr. Chandrakant Lahariya, epidemiologist, public health expert, author and formerly with the World Health Organization. Special Arrangement.

Dr. Chandrakant Lahariya, epidemiologist, public health expert, author and formerly with the World Health Organization. Special Arrangement.



“We have seen till now in the pandemic that nearly all manufacturers have fallen short of their projected production capacity and ability to scale up production. My analysis shows that by the end of July 2021, India is likely to conduct an additional 200 million vaccinations [that would take the total to 380 million total vaccinations]. A realistic estimate for vaccine availability for between August-December 2021 is around 1.3 billion doses.”

Combining data from the serology surveys of the Indian Council of Medical Research, and inferring that there were 20-30 undetected cases for every confirmed one, it was likely that 50-60% of the population had already been infected and developed some immunity to the virus. Considering that the majority of infections have happened in March 2021 onwards, Dr. Lahariya reasons, this sub-group would have some form of protection from infection till December 2021. The real challenge could come thereafter and preparations are key, he said.

Dr. Lahariya, who was formerly with the World Health Organisation, said that there was no evidence so far that a potential third wave would make more children seriously ill with COVID-19.


Full text of the interview:

‘There’s a long list of what could have been avoided or require re-thinking in COVID-19 vaccination in India’

Do you see the extension of the dosage interval between the two doses of Covishield as driven by a combination of scarcity or purely driven by the results from the UK, that shows longer duration may have contributed to keeping disease low?

What we need to remember is that vaccination schedules/intervals are always based upon a combination of scientific evidence and operational realities. As an example, the optimal gap between two doses of vaccines administered to children is 8 weeks. That’s what most countries do. However, in India’s national programme, vaccines are recommended at four weeks of interval. The scientific evidence from the clinical trials of the Oxford/ Astra-Zeneca vaccine (Covishield in India) is that efficacy improves with an increase in the dosing interval. India started with the shortest possible gap of 4-6 weeks [and continued with that even when the global bodies recommended a longer gap] and now moved to another extreme of the longest gap [between two shots] in the world. (Spain is the only other country that has extended to 16 weeks, only for people younger than 60 years). Now, operational reality is that this decision has been taken in the wake of supply shortage. However, that is how vaccination programmes should work — taking the available vaccines to the population which will benefit most. But I am intrigued by two things: why India waited so long to extend the gap and why suggest a window after 12 weeks? It should be soon after 12 weeks, there is no rationale in 16 weeks.


How do you evaluate India's vaccination drive so far? Should the government have opened up vaccinations for 18-44 when our rollout and ordering strategy was on the assumption that we needed to go from older to younger?

Well, COVID-19 vaccination in India has either been too slow or too quick. India was too slow in securing the vaccine supply. It was too quick in opening up for 18 to 44 years of age group, and that too when there was shortage of vaccine even for the then eligible target population. The government should not have opened vaccination for all in 18-44 years. There is a long list of what could have been avoided or require re-thinking in COVID-19 vaccination in India. Intention (to deliver vaccines to everyone) is not enough, there has to be a concrete plan and all that should matter is that the vaccine reaches to the arms of people who need it, in a timely manner.What is unsettling is that this decision seems to have been made without learning from the past. India in the past has done really well on mass vaccination drives. There have been times when national pulse polio immunisation days would be postponed till assured supplies of the vaccine [were available]. In addition to the polio programme, there is a lot to learn from four decades of experience from the universal immunisation programme in India.

Can free market principles of states procuring vaccines on their own work without consequences?

There is no logic of States procuring and paying for the COVID-19 vaccines in midst of the pandemic. When there are known demand-supply gaps, this decision combined with a free market approach for vaccination, has put States in an unchartered territory. To my knowledge, none of the countries in the world has tried that for the COVID-19 vaccine. Across the world, federal/Central governments have acted as single purchaser, leveraging their negotiation powers with the manufacturers. Second, most Indian States have weak procurement and supply capacity, and dealing with vaccine manufacture when that product is in short supply, doubles up the challenge. In the polio eradication programme, it was the Centre which used to procure vaccines and deliver to States. Could India have eradicated polio if the policy was that for 0-2 years, the Central government will procure and supply, and for the rest 3-5 years, State governments have to find their ways to secure vaccines?

Also read |  Bharat Biotech commences direct supply of Covaxin to 14 States

You are someone who’s written on the history of India’s tryst with vaccines. Do you think government’s claims of having 2 billion doses of vaccine from August-December this year is tenable?

The short answer is no. First, four of those vaccines are in various phases of clinical trials, some in phase 1-2. We don’t even know whether those would be licensed (after review of safety and efficacy data) and when. Those four candidate vaccines are estimated to provide 500 million-odd doses. Second, we know that vaccine development and scaling up production is a complex and time-taking process. Nearly always, it takes longer than what one wishes for. We have seen till now in the pandemic that nearly all manufacturers have fallen short of their projected production capacity and ability to scale up production. My analysis shows that by the end of July 2021, India is likely to conduct an additional 200 million vaccinations (that would take the total to 380 million total vaccinations). A realistic estimate for vaccine availability for between August-December 2021 is around 1.3 billion doses. However, merely availability/supply would not automatically translate to those vaccines being administered to the people. There is a need that the government and the relevant expert group and task forces must develop a plan to use these vaccines, taking into consideration the different supply scenarios and how to optimally use vaccines for maximum benefit to fight the pandemic.

Should we now brace ourselves for a third and fourth wave?

It is important that we understand what an epidemic wave is. When a disease spreads, the cases rise, and then interventions start, cases fall before settling down at a lower number of cases. When new cases are plotted against the time period, we see a pattern, which is termed a curve. We know that with ongoing measures, cases in the second wave would decline before flattening of the curve. However, applying the principles of epidemiology, the flattening of the curve after the second wave is likely to happen at a high baseline, which means India may see something like 100,000 daily new cases for many weeks. That could still be termed the end of the second wave in many States. Thereafter, the decline would be incremental and dependent how well vaccine coverage is scaled up. At that point, if there is a sudden and sustained spike in the cases, it would be a third. There is a definitive possibility that fresh wave/third wave would remain restricted to select States but would have an impact for the national curve as well.

Let me explain this. The third national sero-survey found 22% prevalence when the country had reported nearly 1 crore confirmed cases. It has been reported that for every lab confirmed COVID-19 case, there were 20 to 30 unconfirmed cases. Since February till now, an additional 1.5 crore new COVID-19 cases have been reported and by the time this wave would be over and stabilised, the country may see another 1 crore new infections. This essentially would mean anywhere 50%-60% of Indian populations already being infected and having developed immunity. Again, factoring in everything, including immunity after natural infection disappearing with time, considering the majority of infections have happened in March 2021 onwards, we can hope that this sub-group will have some form of protection from infection at least till December 2021. As the vaccination drive is on and coverage of 40% upward of the population even with a single dose will provide some protection. That will leave a fairly small susceptible population, at least till the end of the year.

However, there would be two concerns. One, this year, even with high natural infection and reasonable vaccine coverage, there would be sub-parts of districts and the States, which could have a susceptible population, high enough to report continuous cases or rise in cases. Second, the real challenge would start early 2022, which is reasonably distant from the current second wave and also the effect of both natural infection and the vaccination would start waning off (we really don’t know enough). We have to be alert for emerging new strains of viruses, which are becoming realities, every passing week. And that is the period for which preparedness and response should be focused. There would be a few smaller waves of COVID-19 in India, starting late 2021 and in 2022. We need to be prepared.

Will children be more susceptible?

There is a lot of talk going on that children will be more commonly affected in third wave. It partly comes with the assumption that the entire age group of younger than 18 years is fully susceptible. Through the findings of various sero-surveys, we know that infection in children was not very different than the adult population, just that children do not seem to get serious infection (because they have under-developed ACE-2 receptors, to which the virus latches in order to cause disease). There is no evidence from any part of the world that children are more susceptible in any wave. Let’s take the U.S. and Israel. Are there reports of children getting infection? No. Though, it is possible that the proportion of vaccinated adults will go up, who then may have less infections, the proportion of infections of hospitalisation due to COVID-19 in children may go up, but that is not the same as children getting more infections. I have no reason to think that infections in children in absolute numbers or in the form of a severe disease will rise. We need to prepare but try to avoid any unnecessary concern or alarm. One of the discourses which is largely missing is the vaccination of children. Aspects such as which will be the most appropriate vaccine for children? What will be the purpose of vaccination in children? In my opinion, while selecting a vaccine for children, preference should be given to one which shows a role in preventing transmission. Maybe, nasal COVID-19 vaccines could be the best option for children, as those will have an advantage in quick scale up as administration of those vaccines will be easy. These are many areas in COVID-19 vaccination, where extensive expert consultation and advanced planning should be done.

We have read a lot about how India ‘missed’ the second wave? As an epidemiologist, having more than a decade with international health organisations and been intimately familiar with the history of epidemics in India, are warning signs genuinely ‘missed’ or ignored? How much blame should be ascribed to India’s leadership?

For one, the way the pandemic was unfolding globally and many countries (except China) had two or three waves, these were reasons enough not to think that India was in the endgame. Second, the first wave was delayed by a few months in India. We gave excessive credit initially to the nationwide lockdown and then attempted to search for an answer in ‘Indian exceptionalism’. The virus was still around and the States with relatively better and transparent reporting systems such as Kerala and Maharashtra were reporting a sustained transmission. Though new cases had come down from other parts of the country, the transmission had never stopped. Third, we know the limitations of our disease surveillance system and the quality of data recording and reporting system. Fourth, national sero-surveys informed us that before India started the COVID-19 vaccination, 78% of the population was still susceptible. Finally, the world was still in the pandemic and the preparedness and response efforts were not commensurate with these signals.

The accountability for pandemic response has to be examined in a much broader perspective. It is about the promises on health made by the political leaders at both national and State level over the last few years. Have those been followed though, and why not? It is also about why one year was not used to prepare the health system? The convenient narrative of taking the credit for all the little success in pandemic response and for failures terming it ‘irresponsible citizen’ actually weakens the tenet of citizen participation in pandemic response. It makes two sides non-cooperative and even hostile. Many of the approaches for pandemic response were ad hoc or temporary. The health system in India has suffered because of this ad hoc approach. I think anyone who had given credit to themselves for successfully handling the first wave, should take responsibility for the situation India landed up in the second wave.

From an epidemiological perspective, how should we really be modelling epidemics?

Modelling is an important tool in epidemiology and public policy, and more so in epidemics and pandemic. It provides necessary direction for planning and timing of the resources. We should use this tool intelligently. As with any other method, it has limitations. One of the key limitations is the availability of timely and granular input data to help make more reliable projections. The epidemiologist and infectious disease experts also need to work with the disease modellers to arrive at the right kind of assumptions to feed into the modelling. It is often the failure to provide the relevant data and informed assumptions that modelling goes off the mark. Moreover, an effective public health response can also mean that projections would be proven wrong. Therefore, in some cases and not always, the success of the disease modelling is in failure of those projections.

What are the key lessons that India must incorporate for the future? From a historical perspective (post 1947), can you recount a couple of examples of how certain epidemics have been able to institutionalize certain healthcare practices?

Epidemics and pandemics is an area which can provide innumerable learnings, including for overall strengthening of health systems. However, this is also an area where everything is quickly forgotten. In pandemic preparedness and response, ‘looking back is real looking ahead’. Since Independence, India has been affected by a series of epidemics and pandemics, though impact has been variable. However, four of these pandemics which affected widely in India are the influenza pandemic of 1957-58; the seventh cholera pandemic of 1961 onwards; HIV/AIDS starting late 1990s and still ongoing and the swine flu H1N1 pandemic (2009-10). There have been many epidemics but smallpox in 1974 and plague in 1994 are the major ones to remember.

While studying these pandemics and epidemics is fascinating, unfortunately, India has learnt far less from these important public health challenges than many other countries. What are the broad learnings from the past? One, the core strategy to respond to the epidemic and pandemics are the same — these include testing, contact tracing, isolation, public education on preventive measures and vaccines — and require preparedness well before the disease affects. Second, there is no alternative to a well-staffed and well-functioning disease surveillance system, funded by the government and nested into overall health services. Third, in every pandemic, vaccines have been considered an important tool. Their deployment requires detailed planning. However, soon after, the attention from vaccines has been lost almost every single time. Fourth, in such situations, the cases and deaths have always been undercounted, but estimates have provided better pictures and higher numbers than reporting during the pandemic period. One of the biggest and longest lasting and still ongoing pandemic is HIV/AIDS. It has taught us many lessons, especially in response — community participation, effective public health communication, of the global solidarity, potential of scientific research and TRIPS waivers for medicine and why government should take the lead.

Interestingly, every pandemic has witnessed the use of unproven medicines and therapies, from both traditional and modern medicines. As an example, in the 1957-58 influenza pandemic in India, Iodine in various forms was used extensively as experimental therapy. There is uncanny similarity with the use of various drugs including Remdesivir, hydroxychloroquine and convalescent plasma therapy in the ongoing pandemic. Back then, many controlled and uncontrolled trials were conducted, which used Iodine as throat paints and even in injectable form, with most coming out with interpretations such as ‘Iodine works in severe illness but no benefit in mild illness’ and various versions of it. From the ongoing pandemic, there will be a need to look into development and implementation of standard treatment protocols in India. Unlike 1957, now with indiscriminate use of steroids, antibiotics and other medicines, there is a real risk of development of various long-term liver and other organ complications and emergence of antimicrobial resistance. It requires interventions from the government.

All health experts and policy makers need to regularly look back to prepare the world for the stronger health systems and effective responses to epidemics and pandemics.

The purpose of test, trace — at least last year — was to isolate and have authorities, thus control infection spread. However even though the Centre doesn’t acknowledge it, we are in stage 4 community transmission like the U.S. and Brazil. How relevant is testing now, also considering that COVID-19 doesn’t even have a standard treatment protocol to contain viral replication in the early stages.

From a public health perspective, COVID-19 testing is akin to feeling the pulse of a person who comes to a physician with any health problem. Checking pulse does not reveal the entire illness, but helps in making a diagnosis. That exactly is the purpose of testing in the pandemic. It has some benefit at the individual level, but a bigger benefit to guide larger public health response. A confirmed test can help in early treatment and alert their contacts. Yet, at the group level, it helps in tracking the effectiveness of strategies being implemented to tackle the virus. Testing is relevant at every stage of pandemic response. Till we are in the pandemic, we need continuous testing and scaling up in additional areas. It is also true that testing can only be expanded to an extent. Therefore, it will be equally important that available testing facilities are optimally utilised. In India, now is the time to expand and deploy COVID-19 testing services to rural parts of the country. If we don’t know what is happening there, it will be a grave mistake.

What prompted you to write a book and how did you set about collaborating with eminent experts such as Gagandeep Kang and Randeep Guleria?

A few weeks into the pandemic, everyone realised that we need to fight the info-demic as much as we have to fight the virus. Also, there was a lot of talk about strengthening health systems, but understanding (of those talking about health systems) was not always complete. This is when I came up with an idea to write a book nested into the pandemic, aimed at a wide range of potential readership, including policy makers and general public. That’s how the idea started.

And then, I would say, I was fortunate to have them as co-authors. I first met Dr. Kang in 2008 and Dr. Guleria a few years later. It will always remain very special to me that both of them agreed to my suggestion and request (to join as co-author) in the very first conversation. A common shared passion for science communication had brought us together and each of us felt that such a book should be written. It was completed like surgery in the emergency room, everything done with due diligence but at lighting fast speed. The time taken from the first conversation to release was less than six months.

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