Everything You Need to Know About Herd Immunity
The term “herd immunity” has been doing rounds on the web of late concerning the coronavirus outbreak. So, what is this herd immunity?
In the case that the majority of a population becomes immune to any particular infectious disease, it tends to provide a certain type of indirect protection. This is termed as “Herd Protection”, or as it is better known, “Herd Immunity”. However, this is only applicable to individuals who have not yet been able to build immunity towards the particular disease. So basically, when eighty per cent of any population grows immunity towards a particular virus, out of every 5 people, 4 of them will not fall ill with the disease and will not be a carrier and/or spreader of the disease (on average). Thus, infectious disease is kept from spreading.
Percentage of Population Required To Be Immune To Achieve Herd Immunity
In case the disease is not very contagious, it is possible to achieve Herd Immunity if even half the population achieves immunity against it. However, that number can go up to 90% of the entire population, by the severity of contagion possibility of the disease.
Achieving Herd Immunity
The global population has achieved herd immunity towards a host of infectious diseases over the years. So it is a good place to start when trying to find how a population achieves herd immunity. There has been a long list of critically infectious and/or life-threatening diseases that have plagued the world, like mumps, chickenpox, polio, measles, etc. However, with the introduction of vaccines, the world population has grown effective herd immunity towards all of these. The only few times we have seen small breakouts of any of these vaccine-preventable diseases, it has occurred because the affected communities did not have herd protection towards the disease(s).
For the diseases for which there has not been a vaccine developed, a part of the population may grow immunity (owing to prior infection). However, the individuals who have a weak immune system will still be susceptible to that disease. This was the case for a number of the aforementioned diseases, before vaccines were developed for them.
Natural immunity may help to establish herd immunity, but it doesn’t function as well as vaccines. There are several explanations for this:
- All will have to develop the disease once to become immune.
- Contracts can have health threats, even serious ones.
- You do not know if you have developed the disease or if you are immune to it.
Immunity Against Other Viruses
Several viruses, for example, the Flu Virus, keep on mutating and evolving with time. So the molecular structure of these viruses is different over time if put under the microscope. As a result, the antibodies that an individual may develop owing to prior infection will only protect the individual for a limited period of time. E.g. For the Flu Virus, this span of time is generally less than a whole year.
The Coronavirus situation has turned into a global pandemic of the present day. Now, in the case of “SARS-CoV-2”, the virus that is responsible for COVID-19, the most likely scenario is that the infected people will remain immune to the virus for a time period, ranging from a few months to a few years. However, they will definitely not be free from the risk of infection. Until we study a little more about the infection, nothing concrete can be commented upon.
It’s imperative for us to understand COVID-19 immunity in detail before we conclude how much of the population is immune and how long the immunity lasts, let alone to make potential forecasts. These obstacles should rule out all proposals that aim to increase immunity within a population by encouraging individuals to become infected.
Final Words
Herd Immunity also is known as population immunity which means that there is some level of control over the spreading of disease. However, it is a common misconception that it is a cure. It is a situation that arises after either an individual recovers from an infection or individuals get vaccinated against infection. So it is always a prudent measure to research about spreading disease, to know how to keep yourself safe and to get proper vaccinations for your whole family.
