2020-09-17

Do You Know What is Herd Immunity in Context with COVID-19?  

Have you heard about herd immunity? This is often referred to as people talking about spreading of COVID-19? It is also called as community immunity. It is related to group protection against any communicable infection.

Few experts have suggested that this can be one effective way to prevent spread of coronavirus too. Herd immunity is a condition that can be acquired when majority of population becomes totally immune to the infectious disease as a result it prevents spreading of the disease.

Based on how contagious any disease can be, about 70 – 90 per cent of the population will need immunity for attaining herd immunity.

We can achieve this in following 2 ways:

  • With vaccination of most people to achieve immunity for the disease
  • Many people may contract the disease, but after certain period of time people will build immune response to the disease. This is called natural immunity.

For any less severe diseases like polio, mumps and measles, such kind of approach was achievable, but for present COVID-19 problem, situation is quite different because the virus may carry much higher risk and can also cause severe disease and death too.

That is one reason people are advised to wear BYD N95 face masks while you are within your community and even if no one is infected due to this virus.

How does this herd immunity really work?

If majority of people within the community becomes immune to certain disease, then the spread of that kind of disease will be prevented or slows down. As the chain of the transmission from one individual to the other is broken when majority of people are immune.

In this way, vulnerable population or people who are not even vaccinated including children, elderly and babies with weakened immune system will remain protected.

For certain diseases this theory works. A number of countries have achieved herd immunity partially for swine flu that caused by H1N1 virus by using vaccination. Herd immunity can reduce spread of diseases within a country or region.

However, it cannot guarantee total protection for each and every individual, though it helps to reduce how many people may get affected.

Such herd immunity cannot work for all kind of diseases. For example, tetanus which does not spread via one person to the other can be prevented only if an individual has been vaccinated.

Herd immunity for COVID-19

At present COVID-19 can be prevented only by social distancing, frequent hand washing and wearing masks. Herd immunity cannot successfully prevent spreading of this new coronavirus due to following reasons:

  1. No vaccine available yet for COVID-19.
  2. Successful antiviral specifically for COVID-19 still being researched.
  3. Still scientists are uncertain whether after contracting COVID-19 once or more people can develop antibodies
  4. Many people who may be infected with this virus can develop symptom that is life-threatening and lead to death too. Elderly people particularly with pre-existing health conditions are quite vulnerable.  Even healthy and young people are also becoming very ill.
  5. If many people are tested COVID-19 positive simultaneously, then healthcare systems will get overburdened, which can cause very serious collateral damage on the present health care system.
  6. Our doctors still do not know why few develop severe complications and others don’t.