Covid 19 has so far behaved like other respiratory viruses. Though the number of cases and deaths were far higher in the second wave, the disease was more severe and the risk of death was 1.49 times higher during the first wave. The overall CFR was 1.16 per 1000 person-days (PD), which declined from 1.80 per 1000 PD during the first wave to 0.77 per 1000 PD in the second wave. (8).However since the numbers of those infected were much higher, the number of deaths were also much higher in the second wave. The second wave was largely driven by the delta variant, known for higher transmissibility, but not for more severe disease (some studies did show a higher CFR, though!). The third wave was related to the Omicron variant, where the disease’s severity was even lesser, though to a large extent this was due to the protection vaccination that was offered. There are several reports of the disease having been more severe in the unvaccinated.

However, evolutionary biologists also caution that there is no such law that as evolution proceeds, virulence will decrease. In the worst-case scenario, it is quite possible that a virus strain may emerge, that is highly transmissible and has a higher case fatality rate and is capable of immune escape, viz. past infection or current vaccines do not provide adequate protection.

The virus is still here, it is still evolving, it is still causing deaths and we still do not know enough about its long-term effects. The question we ask now, as we reflect over the last four years’ experience, is what have we learnt that would help us prepare and deal better. Without doubt the Pandemic Agreement and the amendments to the International Health Regulations would be important legal and global instruments for a better response. The focus of these discussions is on technology-based counter-measures. But in this article, we take stock of some specific pandemic response strategies that were deployed  during the recent pandemic and what we have learnt about them. These include:

Pandemics have occurred many times in the past and quarantines have been imposed. But such lock-downs are unprecedented. Even the term is new to public health, and cannot be found in any standard text-book. Lockdowns are often discussed as part of non-pharmacological interventions which is partly true but largely misleading. In a quarantine those who are suspected of having been infected are kept in isolation till the disease manifests itself. It could mean the population of a particular city if the disease is known to have spread widely there. But in a lock-down, it is the healthy population who are being quarantined from being exposed to an unknown source of disease as a form of interruption of transmission. In India, it was expressed as preventing community transmission from setting in. If that was indeed the goal, it miserably failed. If the objective was to give time for counter-measures to become pandemic-ready, or of reducing cases from peaking and preventing overwhelming of hospitals, then there could be a case for a judicious, evidence-based application of some social restrictions.

We now know a lot about the adverse impacts of the lockdowns. There are now a significant body of publications on lockdowns. Several studies that have documented the adverse impact of lockdowns on food security, on livelihoods, on the economy, on education, on mental health and on gender relations (12). Most of these studies have also pointed out huge increases in inequity on every economic and social parameter.  Not only journal publications, but there are many books as well. One example of such documentation are the case studies from India, Angola, Argentina, Ghana presented in the book Pandemic Response and the Cost of Lockdowns (13) . In particular Kunal Purohit’s chapter “How the World’s Harshes Lockdown Unleashed a Humanitarian Crisis” documents how it led to the largest and most rapid human migration seen in India since the Partition. Another detailed source material on the impact of the lockdown on the poor is the book- Covi 19, a view from the margins, edited by Yogesh and Sarah (14).

There are a number of studies and papers on the loss of lives due to disruptions in different health programmes, and this includes tuberculosis and HIV control, care in pregnancy, child immunization, non-communicable diseases, cancers and mental health. What we do not know with the same degree of certainty is whether the lockdowns helped reduce the spread of the virus and the morbidity and mortality associated with it, and whether these benefits outweighed the hardships and loss of lives the pandemic-induced lockdown caused.

But would that balance of benefits and risks apply to population groups across countries and within countries where the vaccines never reached, or reached far too late and too inadequately? Were the lockdowns worth it? We have almost no publications in this area.

The Royal Society study, examining this question for high income countries, concludes that “The effective application of NPIs ‘buys time’ to allow the development, evaluation and manufacturing of such therapies and vaccines at scale. So, there is every reason to think that the application of combinations of NPIs will be important in future pandemics, particularly at early stages with novel pathogens when there are knowledge gaps and when therapeutics and vaccines are not yet available.” Fair enough. But what about other populations like in Africa where there were stringent lockdowns, but the vaccines never reached.

A related question is about the stringency and proportionality of lockdowns and the ways used to enforce the lockdowns. A lockdown could be a universal stay at home order (or curfew) where only certain essential services were permitted, and even this was defined narrowly. It could mean closure of public transport, or of all transport including personal vehicles. It could mean shutting down of markets. It could mean closure of work-places and of schools and other educational institutions. The stay at home could be 24 hours long, or it could take the form of night curfews or weekend curfews. The boundary of the shut-down could be a block of apartments or a street, or a concentric circle of a few kilometres around a known disease incidence, or the whole town, or district, or province or country. Many of these decisions were taken by the security apparatus of the government with little reference to the public health community. But has this been subject to public health review since?

Those who agreed with more stringent lockdowns were generally those with good social security, and living conditions and where work-from-home possibility existed. For them the precautionary principle was everything. An example “We do not want to send our children to school since we are afraid they would get covid. We know that covid has no serious adverse effect in most children, but we have to be cautious since it may have a long-term effect. And even if it is only one or two children why take the risk.” Or the argument may go “we know that covid 19 does not spread much in an open environment. The probability of catching the virus from someone going past in a scooter or walking past you on the road is very low. But it is possible. So why not insist on mandatory enforced masking even in such circumstances.”

But for those with no social security, or who need to go to work daily, or where living conditions are poor, it is proportionality that is the main issue. Is the suffering and risks that a specific population faces due to restrictions outweigh those faced due to the disease? Would not the principle of Common but Differentiated Responsibilities and Respective Capacities, which has been applied to medical counter-measures, equally apply to the issue of social restrictions?

The reality is that we really do not know the answers to any of these questions, and there is little ongoing research or expert committees at work trying to answer them either. The chances are that if we have another pandemic, we may experience the same madness all over again, with little learnings even in finetuning decisions and processes of social restrictions better than we did before. Several chapters in the book (13), “Pandemic Response and the Cost of Lockdowns”, looks at some of the determinants of this silence.. It has some chapters that reflect on why such an enquiry did not take place.  One of these is the way the boundary of what could be debated got drawn within the policy community and in the public discourse, with some considerations a priori being labelled as inconsistent with a scientific outlook. In high income countries, right-wing politics, made an uneasy alliance with science sceptics and industry interests to deny the seriousness of the pandemic and this made democratic discussion on these issues within the scientific community difficult, with sceptics of the lockdown having to subscribe to the group-think on the issue. Second, was the systematic ignoring of proportionality and equity concerns, in favour of an overly precautionary approach. And third, was the difficulty of challenging any opinion which was considered as “rooted in science” as identified by whoever were declared the authority figures within science.  One author (of the chapter on proportionality of response) concludes: “To be fair, the respective ideas whose far-reaching absence in the public discourse I bemoan in this chapter- thinking more about the costs of lockdowns to freedom, questioning the relevance of average age of the people dying of covid 19, questioning the preference given to the protection of life over other considerations- were all at one point considered and discussed. But they were rejected too quickly and eradicated from the realm of respectability too fiercely, leaving the lockdown endorsing strategy as the only acceptable one and pushing the discussion of alternatives into the public sphere.” (page no 167)(13).