India’s daily new COVID-19 cases have crossed the 8,000-mark for the first time after more than 100 days. However, the cases (moderate to severe) and COVID-19 related hospital admissions continue to be low. The spike in infections has raised some worries about the start of the fourth national COVID-19 wave in India. Epidemiologically speaking, an immediate major national wave in India is improbable. Part of the reason is that the Omicron (B.1.1.529) variant is the only globally circulating variant of concern, as of now. The Omicron sub-lineage BA.2, which caused the third national wave in India, continues to be the dominant variant in the country. Though two new Omicron sub-lineages, BA.4 and BA.5, have been detected globally and reported from India as well, their share is minuscule. Finally, there is no evidence that the BA.4 and BA.5 sub-lineages can cause a major nationwide surge in settings already exposed to BA.2 sub-lineage. Clearly, while the concerns about another national wave are unfounded, the ongoing surge demands for a fresh approach to the COVID-19 pandemic response in India.
Epidemiological triad
Then, a key question is if there is no new variant of concern, why this spike in COVID-19 cases? The answer lies in an age-old concept of epidemiology which explains ‘why’ and ‘how’ a disease spreads in any setting: the ‘epidemiological triad’ of agent, host and environment. Spread of a disease is an outcome of a complex interaction of the agent (or pathogen, in this case SARS-CoV-2 and its variants), host (humans and their immune-biological characteristics) and environment (social and behavioral factors).
In the ongoing COVID-19 epidemic in India, since the third wave in January 2022, with minor variations in sub-lineage, the agent (Omicron variant of SARS-CoV-2) has remained largely unchanged. As far as host factors are concerned, immunologically speaking, though antibody levels wane with time and susceptibility to infection increases, declining immunity alone cannot be attributed to rising infection as neither a past infection nor COVID-19 vaccination protect from subsequent infection.
Rather, in spite of an increase in the daily new COVID-19 infections, the low rate of severe disease and hospitalisation shows that our immunity against SARS-CoV-2 is holding up. This brings the third component of the triad, i.e., environment or external factors, at the centre stage. Here, SARS-CoV-2 is very much around, in all settings, as it was for the last many months; and, it is unlikely to go away. However, there is increased travel now, economic activities are back to or even higher than their pre-pandemic level, there are regular social gatherings, and also noticeable lower adherence to face masks wearing in crowded places. Clearly, more than the agent and the host, environmental factors are driving the spike.
However, as SARS-CoV-2 is likely to be around, and as infectious diseases experts and especially those who have studied respiratory viruses would argue, localised COVID-19 case spikes are going to be a reality in many settings and for many months (and possibly years) to follow.
From an epidemiological point of view, the COVID-19 infections in India are not a public health concern any more. The reason is that June 2022 is completely different from March 2020. Back then, SARS-CoV-2 was a new virus; no one had immunity against this virus, and everyone was equally susceptible. There was no vaccine available and the risk of adverse outcomes after SARS-CoV-2 infection by age and other attributes, was unknown and unpredictable. It was clearly a public health challenge.
Nearly 27 months into the COVID-19 pandemic, most people have developed immunity either after natural infection (during three national waves) or through vaccination (nearly 97% of the adult population has received at least one shot while 88% has had two shots of COVID-19 vaccines). There is better scientific understanding of who is at higher risk of severe outcomes (everyone in the 60 years plus group and any age group with co-morbidities or weakened immunity), and the risks are known and largely predictable. Arguably, COVID-19 is less of a public health issue and more of an individual health issue.
A dynamic response strategy
Yet, a rise in daily new cases should not be ignored. However, continuing the five-pronged ‘test, track, treat, vaccinate and COVID-appropriate behaviour’ approach is not the best strategy for India any more and needs to be thoroughly revisited.
First, urgently revise the indicators to monitor and track the COVID-19 situation. The daily COVID-19 infections and test positivity rate may continue to be recorded but have limited utility for decision making. The two operational monitoring indicators which should be used now can be daily new symptomatic COVID-19 cases and new hospitalisations.
Second, any setting which reports a spike in COVID-19 cases should be prioritised for enhanced and expanded genomic sequencing, including the sequencing of all hospitalised COVID-19 cases and a subset of asymptomatic and the mild symptomatic cases, to track the emergence of any variant. A stronger linkage between health departments and the Indian SARS-CoV-2 Genomics (INSACOG) Consortium network conducting genomic surveillance is needed to correlate the variants and the clinical outcomes.
Third, from now onwards the risk of SARS-CoV-2 infection in India (or any setting across the world) is unlikely to be zero. Face masks and physical distancing have proven benefits in reducing transmission, but the benefit, at least in settings such as India, now is far greater at the individual level than at the population level. All social and economic activities (including schools) should continue to function to their full capacity. The face-mask recommendations should be calibrated, targeted, context-specific and evidence-guided and not uniform for the entire population. Science communication and public education should be used to nudge high-risk population groups to adopt such behaviour. The mandatory face-masks requirement for school-going children (implicit or explicit), is unscientific and without evidence. Mask guidelines for school children should be voluntary, without indirect coercion as is the case for some Indian States.
Booster shots
Fourth, there is a known benefit of third shots of COVID-19 vaccines in select, specifically high-risk population groups; however, the benefits of fourth and fifth shots are marginal and short lasting, as studies have pointed out. Essentially, just one additional COVID-19 vaccine shot to get some enhancement in the level of antibodies and possible protection make some sense. Because of hybrid immunity in India with two shots of vaccines and three national COVID-19 waves which are unlikely to have spared anyone, even with only two vaccine shots in India, the protective immunity might be equal to even greater than three vaccine shots in countries with low infection rates.
Therefore, Indian health policymakers need to be very strategic and pragmatic in the use of a third COVID-19 vaccine shot. Every surge should not result in a renewed demand and a push for booster dose uptake for adults in all age groups. After all, if you have to take just one precaution shot, there is merit in delaying it and spacing it out as long as feasible and also getting a heterologous vaccine shot. Similarly, there is no scientific rationale to rush to vaccinate children younger than 12 years.
Fifth, a disproportionately high attention on COVID-19 is not completely innocuous and rather, it diverts attention from other equally and even more pressing health needs such as tuberculosis, diabetes and hypertension, which affects a far greater proportion of India’s population. It is undoubtedly time, Indian States bring the attention back on long-standing health challenges and on strengthening primary health-care services.
What must be done
After the 1918-20 flu pandemic, the influenza virus continued to be in circulation and present even today. In the last 100 years, with regular mutations in influenza viruses, there has been a seasonal rise in cases, outbreaks, and epidemics and two more influenza pandemics (1957-58 and 1968). Since then, there are annual flu seasons across the world. Being another respiratory virus and an RNA virus with a propensity for regular mutations, SARS-CoV-2 appears to be on the influenza trajectory. Factoring in country-specific SARS CoV-2 epidemiology, the population-wide application of the pandemic response in India can be transitioned to be focused on individual protection. India’s COVID-19 response strategy, in the days and the months ahead, should focus on protecting the vulnerable; promoting voluntary face-mask use; strengthening COVID-19 surveillance, and using local COVID-19 data for decision making. We are on the path of learning to live with COVID-19.
Dr. Chandrakant Lahariya is a primary-care physician, epidemiologist and public health specialist. He is Founder-Director of the Foundation for People-centric Health Systems, New Delhi
