World wide health organizations are hopeful that the population of the world will develop herd immunity against Novel Corona Virus.
Herd immunity is when a major portion of the population of any country, say 60 to 70% develops anti-bodies against an infection due to contact with an infected person but the infection they get is so small that even without their realization the body accepts the infection and then internally develops enough resistance to the infection that any further exposure to the virus does not develop into symptoms and death.
But research in countries like Spain, Italy, China is telling a different story. It seems that the virus is mutating (changing its structure) quickly and while a person may develop immunity to one strain of the virus, it does not develop immunity to all strains of the virus by developing immunity to one strain.
There have been surges in all countries where it was thought that Corona virus has stopped affecting people. Even in China, the virus has once again started affecting people even in Wuhan, the place of assumed origin of the virus.
Thus to depend on herd immunity to solve the problem of a country as large as India would be to fool oneself and let one’s guard down.
A vaccine looks like the only hope in the long term. But a vaccine too would suffer from the same problems of a mutating virus. While a vaccine may protect you from a particular strain (for which it has been developed), it may not give you blanket protection against all Corona Virus strains.
Therefore the Health Ministry of India has issued a caution, saying that herd immunity may not work for a country like India.