India needs a strategy to develop herd immunity to survive the Covid pandemic. All strategies that have been adopted so far assume that Covid and its spectre would disappear in a few weeks or, at the most, a few months.
This is wishful thinking. The World Health Organization chief scientist Soumya Swaminathan said in a recent interview that it would take four to five years to control Covid.
Dr Swaminathan’s estimate appears to be in the ballpark. It will take years, and not weeks or months, to control the pandemic. Influenza of 1918 came in three successive waves lasting two years. It ended because those infected either developed immunity or died. The 1889 flu pandemic came in five annual waves and ended finally in 1895. The 1889 flu also died because populations developed immunity.
By Vaccine or Immunity…
Scientists think that Covid will most likely be controlled by a vaccine or herd immunity. The most optimistic scenario is a vaccine within 12 to 18 months. That will have to be followed with mass production and distribution to meet the global need for vaccinating the world’s 7.8 billion people. That will take at least another 18 to 24 months. Rich countries will use their financial heft to garner the vaccine for their people. Despite all the talk of international cooperation, developing countries will have to wait for their turn.
Herd immunity, on the other hand, can be acquired quicker. A study by researchers at Center for Disease Dynamics, Economics and Policy and Princeton University has suggested that India can attain herd immunity among 60% of its population within seven months — or as early as December — if it allows people under 60 to get back to normal life.
India has the most desirable demography to aim for herd immunity: 82% of the population is less than 50, who, if infected, will have mild symptoms; their crude case fatality (fatality if infected) is less than 0.2%.
Another 8% are between 50-59, with a crude-case fatality of 0.4-1%. Encouraging individuals under 60 to restart their normal lives will expose them to the virus and a vast majority, more than 99.7%, will attain immunity. A strategy to acquire herd immunity will improve the chances of surviving Covid with much less damage to lives as well as livelihoods.
A problem in implementing this strategy is that most elderly live in joint families and cannot be easily isolated. One possible solution is that in the first stage, families with no older people can be encouraged to resume normal lives. Only 10% of India’s population is 60-plus. Assuming an average family size of five, this means at least 50%, and possibly 60-70%, of the families have no 60-plus members.In the second stage, the policy can be implemented among families where elderly can be isolated within the household. This two-stage approach would increase the time required to acquire 60% herd immunity by another two to three months.
There are costs and benefits to adopting this strategy. While it will increase death from Covid in the short run, it will also save millions of families from hunger and poverty. It will rescue the economy from a free fall. Within a year or so, Indians would be better equipped to deal with the pandemic when the next Covid wave arrives.
Brace for Next Wave
If Covid-19 is with us for 4-5 years, as Dr Swaminathan predicts, survival strategies cannot be based on economic and travel lockdowns. More people will die from malnourishment; lost livelihoods will become the cause of economic misery and even death.
Note that lockdowns and stay-at-home strategies are merely flattening the curve. The hope is that there will be a vaccine soon, which will grant immunity from Covid to a substantial proportion of the population. The success of this strategy depends on how soon is soon. It is not such a viable strategy if soon is years away.