10 October,2021 08:18 AM IST | Mumbai | Anju Maskeri
People are seen shopping for Navratri at Crawford Market on Friday. Pic/Ashish Raje
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Over the past year-and-a-half, most predictions about the Coronavirus pandemic have been wildly off, and that shouldn't come as a surprise. "Infectious diseases don't play by rules," says Dr MP Cariappa, military veteran, public health specialist and former director of medical services to the Government of India. "Because there's no enemy general planning a strategy; it [spread] is entirely based on human behaviour and the level of immunity among populations." The second Coronavirus infection wave in India earlier this year, is a case in point. It came with severe consequences in the form of spiralling cases, reduced supplies of essential medical equipment, and increasing deaths particularly in the younger population. However, now, with the vaccination pace having picked up, even with subsequent unlocking of cities and towns, cases are under control and life feels much closer to normal than it did six months ago.
Which brings us to the question: Are we nearing the COVID-19 pandemic endgame?
As and when more people get infected with the virus and are fortified by antibodies, the disease's power starts diminishing, thinks Dr Cariappa, adding that every infectious disease has to transition to an endemic state. "SARS-CoV-2 was a novel infection, one that hadn't been seen before. and having run its course, the virus will weaken. But when it will phase out is hard to predict." World Health Organisation (WHO) Chief Scientist Dr Soumya Swaminathan recently said that COVID-19 may be entering a stage where it will become endemic, where some people will get infected but the levels at which it will circulate In a population will be low to moderate. According to the US Centers of Disease Control and Prevention (CDC), the term endemic refers to the "constant presence and/or usual prevalence of a disease or infectious agent in a population within a geographic area". But Dr Cariappa argues that the pathway to vaccine-mediated control of an infectious disease is not always direct. "See, vaccines give us acquired immunity, not natural. So, we will see breakthrough infections [cases of illness in which a vaccinated individual becomes sick from the same illness that the vaccine is meant to prevent], which is normal for a pandemic."
A modelling study published by Science magazine earlier this year said that in a few years, SARS-CoV-2 may be no more virulent than the common cold virus, much like other benign human Coronaviruses that are currently circulating in the population and do not cause severe illness. "There is no end [to the Coronavirus], which means that the virus won't disappear into oblivion. The definition of the end, in this context, is to target endemicity as the exit strategy," explains Dr Giridhara R Babu, Professor and Head of Life Course Epidemiology at Public Health Foundation of India. According to him, the virus will not weaken, but will adapt smartly to live with humans as hosts.
If data from the last few months is anything to go by, it seems we are heading in that direction. Since August 2021, the number of daily new infections in India has been quite stable, observes Dr Trupti Gilada, Infectious Diseases Specialist at Masina Hospital, Byculla. "Right now, out of 28 states and eight Union Territories, almost 25 are clocking two-digit numbers and that's been the pattern for some months now. We were expecting this," she says. The fourth serosurvey conducted in June and July this year, after the second wave had begun to subside, showed that two-thirds of the population has already been infected - a huge jump in the prevalence of infection among the population from previous such exercises conducted. For the first time, minors in the age group of six to 17 years were also included in the serosurvey, with antibodies interestingly discovered in nearly half of them. "This, coupled with mass vaccination, has led to a stage where most of the population in India is immune to a severe infection." According to her, the yardstick to measure the severity of the virus is not by the number of cases, but by calculating hospitalisation and deaths.
The Indian Health Ministry, however, has cautioned that the second COVID-19 wave, which started in April, is far from over. There are several districts across India still in the danger zone. "Please watch your October, November and December - this is a critical period for the country. We have to work together to ensure that COVID-19 doesn't spread and peak again," said Lav Agarwal, Joint Secretary, Ministry of Health and Family Welfare.
Last week on October 6, Mumbai reported 624 cases and seven deaths. This was the first time in two months that the city's cases crossed 600. The last time we hit this number was on July 14 when 635 cases and 10 fatalities were recorded. "It [the numbers] didn't come as a shock," says Additional Municipal Commissioner Suresh Kakani, who has been at the forefront of Mumbai's battle against COVID-19. "This is festival season, and so, mobility and socialising is on the high. We are and will be extremely watchful till December because cases may go up. But the chances for it seem weak because we have vaccinated 93 per cent of the targeted population with the first dose, and more than 50 per cent with the second dose. We are aggressively working to inoculate everyone. In fact, Mumbai is leading in vaccination numbers across India."
Experts say that unless the virus mutates in a manner that enables it to escape this immunity we have collectively built, and begins to re-infect the population in a big way, the chances of a repeat of widespread infection like Mumbai saw in the second wave are slim.
Meanwhile, there's been enormous debate - and concern - about how long-lasting or "durable" immune responses to this virus will be. "There's no consensus on that yet," says Dr Rajiv Sarkar, an infectious disease epidemiologist at the Indian Institute for Public Health IIPH, Shillong. "India has managed to achieve 70 per cent vaccine coverage for its eligible population, but that's only with the first dose. And, global results in the case of Covishield for instance, have shown that one dose is not robust enough to prevent asymptomatic transmission. Now, with global interconnectedness restarting, you can never be completely insulated from infection. In Africa, the vaccine coverage is low, which means there will be reservoirs of infection in pockets. We definitely need more hard data to make any predictions." Dr Babu agrees. "The worst might be over in parts of the world with higher complete vaccine coverage [more than two doses where required]. But we are not safe as long as the virus continues to flourish in some parts of the world."
Earlier this year, a study led by the University of Oxford found that previous infection, whether symptomatic or asymptomatic, does not necessarily protect you long-term from COVID-19; especially against new variants of concern. The then Health Minister Lord Bethell had said in a statement: This powerful study addresses the mysteries of immunity and the lessons are crystal clear. You need two jabs to protect yourself and the ones you love. I call on anyone invited to get vaccinated to step forward and finish the job so we can all get out of this."
Unlike say, smallpox, which the world succeeded in eradicating, COVID-19 will not be wiped out. It will however, stop being a public health concern. "Smallpox was peculiar. It had a single variant, and the vaccine created was 100 per cent effective, and the immunity it offered was life-long. There was nothing like asymptomatic infection in smallpox, whereas in COVID-19, there are levels of severity and a number of variants. Also, the duration of the COVID-19 infection is rather long with aftereffects that continue to linger," explains Dr Gilada.
The complexity of COVID-19 propelled governments, including Singapore, Australia, New Zealand, the United Kingdom, that had in the past announced a zero-COVID strategy, to humbly declare that it is unrealistic, a mission impossible. "Our duty now should be to help countries that haven't been able to get their people vaccinated. The virus strains transmit very quickly, before they can even be identified. And so, a new variant that may emerge in another country will not be a threat to them alone, but to the global scenario," says Dr Gilada.
