Written on, 18th March, 2020 – Updated on 12th May 2021
On 11th March 2020, I heard from the BBC that the COVID-19 outbreak had been confirmed as a pandemic by the WHO. This was the confirmation of a worrying reality which many of us within the field of medical research hoped would never see the light of day. The world was entering unchartered waters with many epidemiological terms which previously were not popularly known becoming household terms. Most notable among these were the terms “herd immunity” and “R”. Imagine a battlefield where the enemy is trying to set an entire army on fire. The enemy will fail to achieve their aim if a significant proportion of opposing forces have fire-resistant gear which will diminish the spread of the fire. In plain terms, herd immunity is collective immunity conferred onto the general population resulting from a significant amount of the populace developing immunity mostly through vaccination. Herd immunity eventually leads to a reduced rate of infection (R).
Ideally, herd immunity should be achieved through vaccination, although it may be obtained through human-to-human transmission of the virus in question. I was surprised to hear this term being touted around as a valid option at the start of a pandemic (with no vaccine), which even to date, we are still trying to understand fully. With hindsight, and the UK currently having the highest number of deaths linked to COVID-19 in Europe, it is fair to say that if the herd immunity route had been taken by allowing the virus to spread further within the populace without early lockdown, things would’ve been even worse than what we see today.
Initially, there was an assumption based on data from other countries that the older generation and those with underlying health conditions were most as risk. These assumptions placed, younger people without underlying health conditions in a possible immune bracket. These assumptions were however shown not to be entirely accurate, when relatively younger people without any underlying health conditions began suffering fatalities. This development prompted a direct warning from the WHO’s Director-General to young people that they were not invincible to COVID-19. These factors coupled with the discovery of strain variations in COVID-19 and lack of a vaccine presents a great challenge to the attainment of herd immunity. The ONS estimates almost 12 million people aged over 65 in the UK contracted the virus; hence with the high mortality recorded in the older population. Allowing the virus to spread further in the name of herd immunity would’ve led to a disastrous consequences.
With hindsight many lessons have been learnt around the world within medical research, governments, and communities. These lessons, although learnt the very hard way will help us prepare for any future pandemic. One principal lesson learnt in this pandemic, which will be valuable in tackling any future pandemic is the need to slow down the rate of spread of the infection as much as possible to buy enough time for research and vaccine development catchup. Such a slow-down in infection rate would also ease pressure on healthcare providers which in the long run will increase the chances of survival for many patients.
COVID-19 vaccine development as well as herd immunity are important factors in the race towards a return to “normal life”. Many vaccines are currently being developed, bringing hope for the establishment of herd immunity against COVID-19 in the future. Until we get to that point and win the race, against this virus, a collective effort is required to minimise the rate of infection which has seen a spike in some countries such as Germany and South Korea after partial relaxation of lockdown measures. I have no doubt, that with relentless determination, humanity will once again prevail, just as it has always prevailed against pandemics in history.
Update – At the time I wrote this article, vaccines were in development but fast forward to 2021 vaccines are being rolled out in many countries around the world, tremendously contributing to the attainment of global herd immunity.