Covid-19 is not going away anytime soon. A leading city doctor sheds light on how to adjust to the ‘new normal’
The Covid-19 pandemic is still with us. So, what would life be like post lockdown? We need to build what we call ‘herd immunity’ — acquisition of immunity for the herd/ community.
What is herd immunity?
Herd immunity is acquired in the following manner. The entire community is exposed to the virus. The result being that nearly everyone gets infected. Once infected, our natural immune response will provide robust antibodies against the virus, which enable recovery. The antibodies, formed from that response to the infection, prevent the sufferer from succumbing to the disease. It also offers protection in the form of immunity from future reinfection to that same virus. The collateral damage is that the vulnerable of that community will get the infection and die.
Why the lockdown?
Sweden followed the modern day version of the acquisition of herd immunity. No lockdown was advised. The purpose of the lockdown in other countries was to limit the transmission of infection, and so the disease would extinguish itself since it would have no one to infect, provided people stayed away from each other. The lockdown has also enabled health officials to regroup, assess courses of action, devise strategies, evaluate and organise medical resources should the viral infection spread. Given the size of Mumbai’s population and its density, the lockdown was not expected to succeed in containing the viral infection. The problem with acquiring herd immunity to exposure is that many people would fall ill. But how ill?
Many people fell sick from the Covid-19 infection and some very seriously ill before recovering. Many persons, who were otherwise in good health and not in the vulnerable category, contracted Covid-19, and then suddenly, and unexpectedly, died. This was a totally new (novel) virus and nobody could predict its behaviour and the path it would take. Therefore, trying to extrapolate the pattern of its behaviour to other coronaviruses like SARS would be a costly mistake.
Time to introspect
The long-term consequences following Covid-19 infection is not known. The measles virus, for example, has long-term sequelae of damaging the lungs causing
Sweden’s modern day version of acquiring herd immunity via exposure did not work out the way it was expected to do. The unforeseen consequences of far more deaths than was calculated have made it a controversial one. Many who were not considered to be in the vulnerable category succumbed to the infection? Many questions present themselves. Just because certain people are vulnerable does that mean we sacrifice them in order for the herd to acquire immunity? Who will decide who is vulnerable and who is not? Do the antibodies to one strain of the virus offer protection against other strains of the virus, which may be more virulent? How long will this immunity last?
The other way to acquire community immunity is via a vaccine. Vaccines provide herd immunity without posing significant health risks to the community. Vaccines are available much later on in the course of the disease. By that time, the virus has wreaked havoc. Preparation of a commercially available vaccine takes on average at least 18 months. While waiting in anticipation for the vaccine, it is wise to also ensure that all health parameters are under control. Vitamin D,
► Wear a face mask correctly.
► Practice social distancing.
► Health hygiene, hand washing, rigorous washing of fomites and other objects on which the virus could possibly reside.
► Ensure/encourage others to do exactly the same.
► Do not delay seeking medical advice if the first signs of illness present. They are
■ Writer is a head and neck surgeon and otorhinolaryngologist