7 min readFeb 22, 2022 09:30 AM IST
First published on: Feb 22, 2022 at 04:50 AM IST
The Omicron-led surge in India — popularly, the Third Wave — saw a rise in new Covid-19 cases beginning end-December for about four weeks. The decline was dramatic, in about three weeks. This phase was marked by less hospitalisations, fewer complications and reduced mortality compared to the Delta-driven second wave. India’s experience replicates that of South Africa. Some of the increase in death counts in recent weeks can be attributed to the “reconciliation” of deaths across states in the light of the Supreme Court’s directive on compensation.
Omicron is the dominant variant currently, globally and India. It is likely to shape the state of the pandemic for some time. The Alpha variant had nine mutations in its S gene and Delta had between nine and 13 mutations. Contrast these with the staggering 50 mutations in Omicron, including 32 mutations in the S gene. A French study found Omicron to be 105 per cent more transmissible than Delta and a Danish study found the variant’s capacity to infect 2-7-3.7 times more than its predecessor. Delta was 100 per cent more transmissible than the parent strain. The WHO had, therefore, warned of a tsunami of Omicron cases overwhelming hospital services despite the virus being less virulent. Indian has, however, weathered this ongoing phase reasonably well.
The Omicron variant comprises three sub-lineages: B.1.1.529 or BA.1, BA.2 and BA.3. As of February 10, India was among the 10 countries that reported a predominance of BA.2 sub-lineage. Emerging evidence suggests that BA.2 is 30 per cent more transmissible than BA.1. However, current evidence from the US, UK, South Africa and Nepal also confirms continued “decoupling” — low hospitalisation and fatalities amidst rising new cases. At the same time, mortality due to Omicron does remain a matter of concern in patients above 75 years, those with comorbidities and importantly, the unvaccinated.
Re-infection, people testing Covid positive 90 days after their last infection, is an emerging concern. The most obvious reason for this is Omicron’s uniquely abundant mutations that make the variant extremely efficient to escape pre-existing immunity. Immunity also wanes since the last vaccination. That’s why boosters are important. Evidence from countries with rollout and high coverage of vaccines, Israel and the UK, confirm protection from hospitalisation or death. The UK’s Office for National Statistics estimates that the rate of re-infection has increased 15-fold in the Omicron phase: Re-infections account about 10 per cent of current infections in England, in contrast to 1 per cent during November 2021. Re-infections with Alpha were symptomatic in 20 per cent cases. In contrast, Delta re-infections caused symptoms in 44 per cent cases and Omicron in 46 per cent. In general, re-infections boost immunity. But such re-infections do not confer 100 per cent immunity.
Analyses from UK confirm protection against mild disease 20 weeks after a two-dose schedule. A booster dose increases it by 65 to 70 per cent. That declines to 45 to 50 per cent after 10 weeks. Protection against hospitalisation after a booster dose, however, is a lot higher — it’s estimated at 92 per cent and remains high at 83 per cent after 10 weeks. The current lot of Covid vaccines provide substantial protection against systemic disease in the lungs and other organs, but do not generate strong mucosal immunity that would be effective against the mild but the early infectious stage that affects the patient’s nose and throat. Mucosal vaccines administered through a nasal spray can correct this significantly but these will quite likely require to be administered repeatedly as the duration of the immunity it confers is relatively short. Bharat Biotech’s intranasal vaccine, BBV154, has received regulatory approval for phase 3 clinical trials for use as booster dose (third dose) for those who have received a primary schedule of Covaxin. If it passes the final regulatory test, the vaccine can be a potential game changer.
The performance of the Covid vaccination programme, so far, provides ample testimony to vaccine confidence — trust in the effectiveness and safety of the vaccine, the system that delivers, including the reliability and competence of the health services and professionals and the perceived motivations of the policy-makers making decisions on the vaccine. In the journey ahead, two key challenges will require to be addressed. One, as perceived risks decline, there could be a rise in vaccine complacency with inoculation not being seen as necessary preventive action. Public messaging must ensure that such complacency does not arise. Two, the drive to make vaccines available and accessible must not flag.
The WHO foresees the acute phase of the pandemic to end by the middle of this year if 70 per cent of the global population is vaccinated — this will limit the emergence of newer variants. The goal of vaccine equity — an ethical imperative as well — has been bedevilled by vaccine shortages and funding and infrastructural inadequacies. Founded on the principles of human well-being, equal respect, national equity, reciprocity and legitimacy, the WHO’s Values Framework considers Covid vaccines as a public good. By and large, however, this message did not receive adequate traction, both across and within countries.
We could witness increased cases over relatively shorter periods, outbreaks of smaller scale and the emergence of new variants. Covid-related restrictions are being relaxed in all states. Isolation guidelines and contact management protocols are changing as well. The core principles of prevention continue to be relevant though: Mask-wearing, hand hygiene and vaccination. This is the time to test risk communication strategies. There needs to more investment in research on social and behavioural aspects of disease management. In fact, dealing with long-Covid will require far greater systemic response than what is being undertaken currently.
In its acute phase in the past two years, the Covid-19 response framework was seen through the lens of a disaster. It focused, almost exclusively, on the mortality and morbidity aspects of disease. Revoking the National Disaster Management Act that framed this response ecosystem should now be seriously considered. A switch to a “slow disaster” framework, instead, will enable re-profiling strategies over the next few years to deal with crises that could be long and complex — the resumption of economic activities and education and removing the trauma and scars of the pandemic.
This column first appeared in the print edition on February 22, 2022 under the title ‘After the wave’. The writer is Chairperson at the Centre of Social Medicine and Community Health, Jawaharlal Nehru University, New Delhi
We could witness increased cases over relatively shorter periods, outbreaks of smaller scale and the emergence of new variants. (Illustration: C R Sasikumar) 
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