With vaccination drives taking place in an entire storm, the words “herd immunity” has been echoing across the globe as many try to configure what it is, and some even using it as an excuse to avoid vaccination. So, what is herd immunity? And will you still need to get vaccinated if herd immunity occurs?
Herd immunity occurs when a sufficient fraction of society gets immune to a disease. Therefore disease transmission between people becomes rare. Hence, everyone, including the ones not immune from the disease, is protected.
This “sufficient fraction” differs based upon the diseases and how contagious it is. Varying contagions require varying levels of immune responses to achieve herd immunity. For example, to achieve herd immunity against measles, at least 95% of the population must be vaccinated. When that happens, measles will not spread among vaccinated and therefore, the remaining 5% will be safe as the contamination chances become close to none.
Amidst the Covid-19 pandemic, initially, scientists believed 60-70% of the population to be immune to achieve herd immunity. However, with the novel virus’ resistance improving, leading immunologists such as Dr Anthony Fauci believes that the percentage may need to shift upwards.
Herd immunity can be obtained in two ways; either by vaccinations or natural infection. With natural infection, immunity is attained if an adequate number of people have recovered from the disease, resulting in their bodies developing antibodies against the virus. As for the vaccination route, once enough people are vaccinated against the disease and have developed antibodies, diseases such as polio and rubella can be successfully controlled.
Nevertheless, reaching herd immunity through either pathway may be difficult with covid-19 as the risk of reinfection is potentially high. Not to mention that the health impacts will be severe if individuals rely solely on natural infection. As of now, myriads of people are hesitant to administer/receive the vaccine due to objections such as religion and other sceptic beliefs. Furthermore, the efficiency of the vaccines to new and more dangerous variants is unclear, allowing some vaccines to have lower efficacy against variants.
Although herd immunity is ideal, certain flaws make it seem more like a myth rather than reality. However, if protocols are inherited, the rate of transmissions may decrease, potentially allowing herd immunity to become a reality.
Citations:
Herd immunity and COVID-19 (coronavirus): What you need to know
"Herd Immunity And COVID-19 (Coronavirus): What You Need To Know". Mayo Clinic, 2021, https://www.mayoclinic.org/diseases-conditions/coronavirus/in-depth/herd-immunity-and-coronavirus/art-20486808 Accessed 26 July 2021.
How Much Herd Immunity Is Enough?
"How Much Herd Immunity Is Enough?". Nytimes.Com, 2020, https://www.nytimes.com/2020/12/24/health/herd-immunity-covid-coronavirus.html Accessed 26 July 2021.
Ng, Abigail. “Myth or Reality? Health Experts Weigh in on Whether 'Herd Immunity' Is Possible.” CNBC, CNBC, 15 Apr. 2021, www.cnbc.com/2021/04/15/herd-immunity-experts-discuss-if-its-possible-to-reach-covid-immunity.html
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