COVID-19: LESSONS FROM INDIA’S EPIDEMIOLOGY


The message being played out in India mimicking the global experience is that one cannot prevent the natural course of a pandemic much by human interventions like lockdowns, physical distancing, school and business closures, or by desperate attempts at mass vaccination.

The present pandemic of CoViD-19 well into its third year continues to throw surprises. The sprint has turned into a never ending cross country marathon. Those group of experts who, in the early days of the pandemic spoke with confidence while mapping out the battle plans have been punched in the nose by the wily virus, despite being double masked and double boosted. The other group that dared to challenge their battle plans, are nursing their wounds from the sidelines, as their loud voices got muffled even without masks, and thus gone unheard or worse, censored.

Early in the pandemic, populations of almost all countries, except Sweden, Japan and Belarus, were urged to conform to restrictive measures to prevent hospital services from being overwhelmed. These unprecedented measures were expected to be for a few weeks to break “the chain of transmission.” Like schoolchildren (and including schoolchildren whose schools were closed), they were coaxed into not going outdoors for recreation, shopping or entertainment and advised to do all their work from home. Surprisingly, all the people across the world complied. The pandemic of panic in this era of social media platforms had spread faster and wider than the virus itself.

Emboldened, governments around the world pushed the envelope. Whatever restrictions were imposed for few weeks, extended to several months, interrupted only intermittently. Dil Maange More on the part of the world governments turned out to be the ethos for those prolonged restrictions never before implemented on a global scale in the history of public health. Optimism of exterminating the virus from the planet, with the roll out of vaccines developed with novel technologies and hyped by media to panic proportions, made people comply.

Vaccines were rolled out in late 2020. Israel was lauded for quickly inoculating its population. Other countries followed with equal speed, particularly, the developed ones. The World Health Organisation (WHO) kept calling for vaccine equity as they deprecated the Western world for hoarding vaccines and going for boosters depriving the Asian and African countries the much needed immunizers.

Alas, the honeymoon period is over. Countries with adequate mass vaccination coverage are facing surges both in cases and deaths – the trends paradoxically higher than the pre-vaccination period. The following graphs based on data available in the public domain[1,2] for Israel, Japan, Taiwan, and Australia illustrate the paradox [Figures 1 – 4]

Figure-1 Trend of cases and deaths in Israel pre and post mass vaccination

Figure-2: Trend of cases and deaths in Japan pre and post vaccination

Figure-3: Trend in cases and deaths in Taiwan pre and post mass vaccination

Figure-4: Australia – Cases and deaths pre and post vaccination roll out

The impact of mass vaccinations of populations seems to be modest, if any. Many other countries in Asia and SE Asia, such as Indonesia, Malaysia, Sri Lanka, Singapore, experienced the same paradox after vaccine roll out[3]. A study published in European Journal of Epidemiology found that trends of CoViD-19 did not correlate with the population level vaccination coverage. The investigators had compiled data from 68 countries and 2947 American counties[4].

While the above findings may seem paradoxical, a close look at the Indian Covid experience will help us understand the dynamics of the pandemic.

India is a vast country with a population of over 1.4 billion. It has huge socioeconomic disparities. It has the richest as well as the poorest people in the world spread out across gradients of socioeconomic classes. CoViD-19 impacted different classes of people in different ways. And restrictive measures like lockdowns and physical distancing, business and school closures led to further “social distancing” with the poor becoming poorer but picking up faster and more robust herd immunity through natural infection; and the rich got richer however remained vulnerable and developed a fragile and uncertain vaccine induced immunity. Subsequent waves affected and continued to affect the middle and upper classes but not the poor.

In the first wave due to India’s thoughtless imitation of the West on restrictive measures, transmission resulted among the poor who lived in the crowded slums and tenements, while the middle class and affluent shielded themselves from the infection by working from home and observing all “CoViD appropriate behaviour.”

Dharavi in Mumbai, India, perhaps the largest slum in the world with a population of one million is the best example of this phenomenon[5]. In the first wave the residents of Dharavi, without vaccination, acquired robust herd immunity. During the successive waves Dharavi was the least affected, whereas the middle class and affluent who lived in housing societies were most down with the virus.

Subsequently, studies from across the world have revealed that immunity acquired after recovery from natural infection is more robust and long lasting compared to vaccine induced immunity[6]. With the arrival of Omicron and its variants the graphs above suggests that vaccine has hardly provided protection at the population level.

In June 2021, after the second wave, 67% of Indians had IgG antibodies indicating they encountered the virus and recovered resulting in robust immunit[7]. As the antibodies levels fall after sometime yet immunity persists due to primed memory and T cells, this figure can be pegged at 80%. A subsequent survey among children below 18 years in Delhi in September 2021 revealed that 82% of them had IgG antibodies, before any vaccine was rolled out to them[8]. Similar finding were reported from several other parts of the country.

Interestingly, the Indian state of Kerala which did very well to protect its people during the early phase of the pandemic, did badly later in the pandemic with surges in spite of vaccine being available. On the global canvass the same pattern is being observed. Israel, Taiwan, Australia, New Zealand, Malaysia and other countries which did very well initially are experiencing surges currently in spite of high vaccination coverage including two boosters.

The message from this phenomenon being played out in India mimicking the global experience is that one cannot prevent the natural course of a pandemic much by human interventions like lockdowns, physical distancing, school and business closures, or by desperate attempts at mass vaccination. One can only postpone the inevitable. With dubious efficacy of mass vaccination one should rework the cost benefit analysis which is an important aspect of health economics in public health practice. Particularly for poor countries like India which have advantage of a large population base of young people who have already acquired robust herd immunity from natural infection. Chasing a rapidly mutating virus is like chasing a deer in the jungle.

Focused protection by vaccination, of elderly and young with co-morbidities on the advice of their personal physician, rather than across the broad mass vaccination would be a more prudent and cost-benefit approach. The resources saved can be channelized to upgrade the vaccine to meet the challenge of new variants, and spend on our more pressing public health needs particularly among the young and children.

To put our public health problems in perspective: We lose over 2000 children daily due to non-CoViD illnesses against a background of malnutrition; around 1400, mostly young, die from tuberculosis daily; 400-500 mostly young are killed every day on Indian roads and many unresolved health issues such as dengue, diarrhoea, typhoid, and so on for which we have yet not developed a good reporting and monitoring system. These are our really major public health problems. Mindlessly imitating the West and dancing to their tunes will push these problems under the carpet adversely impacting the health of our citizens.

(Picture courtesy:Shutterstock)

References:

https://www.worldometers.info/coronavirus/#countries

https://ourworldindata.org/covid-vaccinations

https://www.mjdrdypv.org/text.asp?2022/15/3/293/342521

https://doi.org/10.1007%2Fs10654-021-00808-7

https://www.medrxiv.org/content/10.1101/2021.08.24.21262415v1

ANALYSING HERD IMMUNITY’S EFFICACY THROUGH COVID-19 STUDY IN DHARAVI

https://www.sciencedirect.com/science/article/pii/S1201971221012510

https://www.hindustantimes.com/cities/delhi-news/8-of-10-kids-in-delhi-have-covid-antibodies-101635471193829.html


AMITAV BANERJEE has experience of control of epidemics at different locations of the country such as outbreaks of pneumonia, hepatitis, typhoid, German measles, food poisoning and tribal malaria. https://www.youtube.com/watch?v=bZOWByfbYNY . He can be reached at amitavb@gmail.com


Opinions expressed in this article are of the author’s and do not represent the policy of The Edition. The writers are solely responsible for any claim arising out of the contents of their articles.

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