The SARS-CoV-2 has been springing surprises repeatedly, baffling both scientists and national governments. Scientists are unable to predict the future behaviour of the virus as it mutates and produces variants without warning. Governments are repeatedly pushed between the horns of a dilemma – social restrictions, such as extreme lockdowns, to slow viral spread in order to ‘flatten the epidemic curve’ lead to loss of livelihoods and severely damage the economy.
After a curve due to one variant is flattened, a ‘new variant of concern’ sets the clock back, causing another wave. Many developed countries where social restrictions were more effectively practised have faced four or five successive waves. India has so far experienced two massive waves, first with the original virus variant and the second with the Delta variant that emerged in India as the first wave was receding. Our wave pattern is unique in the world. Kerala stands out as an exception, which flattened the curves and had four waves similar to developed countries.
The Experience With Delta
All stakeholders underestimated the risk posed by Delta until it caused a huge wave – spreading four times faster and causing at least twice the number of disease cases as the first wave. The rapidity of spread was due to the higher basic reproduction number (Ro) of Delta. It could also dodge the waning immunity of first infection, causing re-infections, which then caused transmission chains to continue – intra-family saturation of infection was the rule. Breakthrough infections (in those who had two doses of vaccine) were very common.
Even though all developed countries had access to different vaccines, Delta dodged vaccine-induced immunity in all of them. Such immunity evasion was not all or none – the higher the level of virus-neutralising antibody, better was the protection. Protection was also not all or none – protection against severe disease was of a higher order than that against milder disease and asymptomatic infection. Protection was lowest against ‘breakthrough’ infection.
Omicron variant can spread much faster than Delta – its Ro is much higher than that of Delta and it is more efficient in dodging immunity. It causes re-infections and breakthrough infections more frequently than Delta. So, will Omicron cause yet another wave in India? That remains unpredictable. If we assume it will not, but it does, then India will suffer again. There is no need to elaborate on the scenario as the memory of the immense loss of life due to Delta wave is still vivid in our minds.
If we assume it will cause a wave, and we bolster our immunity defence with vaccines, the wave can be blocked at best, or flattened at least. When there is a threat of flood, do you stack up sandbags beforehand, or be scientifically correct and start stacking them up only after seeing evidence of being flooded?
We Have Lost Precious Time Against Omicron
We have known Omicron only for a month. So far, it seems to be less virulent than every previous virus variant. This may be because vast swathes of humanity have been already exposed and rendered partly immune by the previous variants and a large number of people have had one or two doses of vaccine. Everyone agrees that there will be a massive increase in infections, but much of those will be invisible. A huge wave of disease outbreak is unlikely, as far as we can expect. A disease wave must be expected, only its magnitude is unpredictable, and it may be quite small. However, it will be better to be safe than sorry.
We know that all below 18 years remain unvaccinated by policy, and young age and lack of vaccination will likely result in a fast spread of Omicron among them.
Omicron infects younger people more than the earlier variants, creating a reservoir effect, further enhancing community transmission in the entire population.
Even if disease frequency is low, the sheer magnitude of infections may lead to large numbers of disease cases within a relatively short time span, with a potential to overwhelm our fragile and fatigued health care system.
Senior citizens, all those with diseases or therapies that lower their immune status, all with risk-enhancing co-morbidities, and pregnant women may have to face the onslaught of disease. We have lost one precious month without decisions and action.
Did India Learn Any Lessons From the Two Waves?
The first wave started from mid-March 2020, peaked with 97,859 cases on 16 September and declined to the nadir of 8,947 cases on 8 February 2021. The lockdown declared on 24 March 2020 had little effect on case numbers, as they grew 46 times, from 536 to 24,447 on 24 April – in just a month. The symmetry of the ascending and descending limbs showed that the former was not tamed down with interventions. The diagnosis: the lockdown was premature, ie, it was imposed before transmission had picked up momentum. When transmission accelerated, the lockdown grew porous. The exodus of migrant labour returning to their native villages enhanced inter-state virus transmission, reaching even remote villages We had no vaccines then.
Scientists and industry had successfully made vaccines; emergency use approvals were declared on 3 January 2021. The second wave hit us in March, but we were not ready to dampen it with vaccination – vaccine stocks had not been built up, systematic and rapid vaccination not planned. The wave peaked on 6 May with 4,14,433 cases and declined to below 42,000 by the second week of July. Since then, the daily case numbers have continued to fall steadily, which is the endemic phase, sustained now for nearly five months.
Currently, more than 85% of adults have taken their first dose, 55% have completed two doses.
These, along with the approximately 85% of adults with past infection (data from post-second wave estimate supported by the 4th seroprevalence study) represent a strong wall of population immunity. But Omicron is notorious for its ability to evade immunity.
The vaccine most commonly used in India (AstraZeneca-Covishield) has recently been found to confer effective protective immunity against serious disease and death by Omicron for only three months after the second dose.
The Case for Boosters
In November 2021, we had vaccines aplenty and a clear warning of a probable third wave. Yet, we seem to be very reluctant to mitigate the risk by denying its probability.
Wave or no wave, we need to bolster the wall of immunity further to protect the vulnerable people and prevent a rapid spread of infections.
A very recent technical report from the UK Health Security Agency concludes that booster doses enhance protection against mild/moderate disease with Omicron; the extent of protection against severe disease, hospitalisation and death is not yet measured.
We should expect such protection to be high. Knowing that higher levels of immunity offer better protection, many developed countries are already rolling out booster doses. By definition, a booster dose is one given six or more months after the previous dose.
The UK report had warned that even boosted immunity may not last more than four months against Omicron. Israel, a booster-dose pioneer, has started a study to measure the effectiveness of a two-dose booster schedule for healthcare workers. They are also vaccinating children above five years to keep schools open and to reduce transmission by children to household members.
Vaccines Still Need to Earn Everybody's Confidence
The hurry of vaccine use has also caused much worry among experts and the public. Experts exhibit scepticism, and the public, hesitancy. Unbiased, we need to understand this unprecedented situation – never before have vaccines developed on novel platforms been deployed on such a massive scale. Some safety issues are real, but many feel they are swept under the carpet. Without universal healthcare, the fear adds a heavy psychological burden on people. Vaccines made with conventional time-tested methods like protein subunit or inactivated virus, seem to be very safe.
In countries where monitoring or managing serious adverse reactions are not streamlined or available to all, people deserve complete safety. So, vaccines, which are being touted as the ultimate weapon of defence, have not earned everybody’s confidence.
Policymakers were misled to believe that the induction of minimal immunity with two priming doses was ‘full vaccination’. Any paediatrician would have said the two doses of ‘non-replicating’ vaccines are, at best, partial priming, ie., offering minimal immunity for a short while, allowing more time. For achieving effective protective immunity, you need priming doses plus at least one booster.
India has just woken up from what appeared to be policy slumber. Two days ago, a decision was announced to give a third dose to healthcare and frontline workers and all those who are above 60 years of age and have risk-enhancing medical conditions. The vaccines approved for children by the regulatory agency are ready for rollout to adolescents from 15 to 18 years of age. These are truly in the right direction, but too little too late to block a possible Omicron wave.
The Need for a Focused System
Developed countries – even those with universal primary and secondary healthcare – rely on their ‘health protection’ or ‘health security’ infrastructure for data collection, analysis and interpretation to guide public health policies. Public education on disease details and the value of vaccines is best provided by such an agency. India does not have such an infrastructure.
We hope that the government will realise this deficiency in India’s health management system, for which reason the defence against a disease epidemic had to be entrusted with the national disaster management agency.
(Dr T Jacob John is a former Professor of Clinical Virology, Christian Medical College, Vellore. Dr MS Seshadri is former Professor of Endocrinology, CMC, Vellore. This is an opinion piece and the views expressed above are the author’s own. The Quint neither endorses nor is responsible for the same.)
(At The Quint, we are answerable only to our audience. Play an active role in shaping our journalism by becoming a member. Because the truth is worth it.)