Nearly a year after the detection of its first case, the coronavirus still poses a threat to the health of people and the travel industry of all countries across the globe.
While everyone has their own perspective about handling this unprecedented situation, herd immunity has definitely become a hot potato. Research is being conducted by different companies and universities to determine its efficacy as a solution to the pandemic.
So what exactly does herd immunity mean? How do we attain it? Does it hold water in practice? Read along to know more.
What is herd immunity?
In layman’s terms, herd immunity is a concept in the field of vaccination that says if a substantial part of the population is immune to the virus, it will indirectly protect the susceptible individuals.
The rationale behind this is that most viral and bacterial infections spread from person to person. However, this chain breaks if the majority of people are immune to it and incapable of passing it on, thus curtailing the transmission of the virus considerably.
When and how will we achieve herd immunity?
The concept of herd immunity will be effective only when enough number of people are immune to the virus. The percentage of people that must have immunity to safely slow or stop the transmission of the disease is called the “herd immunity threshold”. Considering how contagious the COVID-19 is, it is expected that at least 60% – 70% of people will be required to have antibodies, although some calculations predict an even higher threshold.
There are two ways to achieve herd immunity – a large proportion of the population either contracts it and thus develop antibodies naturally, or get vaccinated against the virus. Although massive efforts are being taken on COVID vaccine trials, it has not been released and so, as of now, natural immunity is our only option.
Is natural herd immunity really the best way out?
Even if natural immunity has proven effective in the past in the case of diseases like measles, polio, mumps and chickenpox, history may not repeat itself this time around. It’s scientifically problematic and unethical in the very least. Here’s why.
The vaccine is not yet available
While mass vaccination is undoubtedly a safe way to achieve herd immunity from COVID-19, contracting the disease intentionally in the process is not. In spite of modern medicine, the virus can have severe, sometimes fatal consequences on the health of even otherwise fit persons. It may also lead to spread of the infection amongst old-aged, heart and diabetes patients, children and other vulnerable individuals.
Might only be a temporary situation
Compared to the immunity gained from vaccination, naturally built up immunity might not be as effective. Studies are still underway as to how long the immune response and antibodies last after the virus, and whether or not it varies between individuals. Cases of survivors contracting the infection a second time have also been documented, putting a question mark on the validity of natural immunity in the case of coronavirus.
Healthcare system will be exhausted
The drastic surge in the number of patients will unnecessarily overburden the hospitals and healthcare institutions. Government measures to meet the subsequent shortages of beds and treatment facilities will further drain economic resources of the country.
Practically, it’s too far-off
Statistics show that in most of the countries, only less than 5% of the population has been infected with COVID-19 in the past one year. Reaching the estimated threshold will be an inordinate effort, not to mention disastrous to the well-being of humankind.
To revive the severely hit tourism industry, some countries have started accepting “immunity passports“, also called “risk-free certificates”, to make the process of border reopening more prudent. These passports certify the presence of antibodies in an individual, supposedly confirming his immune status.
However, the WHO has clarified that there is no study to prove that the presence of antibodies prevents the infection of the coronavirus the second time.
Moreover, due to the lack of reliability and accuracy of antibody tests, there is a high risk of false negatives and false positives, which can have severe consequences from the standpoint of public health.
Herd immunity in the (hopefully, near) future
Vaccination is currently the most reliable and safe way to battle this deadly virus. People of all ages, irrespective of medical histories, must be given the vaccine doses to create sustainable herd immunity.
In that scenario, even if individuals in remote or inaccessible areas and those who cannot be vaccinated, such as babies, pregnant women and immunocompromised people remain susceptible, the herd immunity of the rest of the population will act as a protective shield for them as well.
Until then, masks and proper hygiene are indispensable. Social distancing norms and precautionary rules imposed by the governments must be strictly adhered to.