PremiumCovid-19: The world should not have discussion over 'heard immunity' as it is not going to happen, considering the type of coronavirus mutations that have occurred over such a short period of time, an expert has said. Mutations have resulted in the virus becoming both more transmissible and more able to evade immune responses, something that very few scientists predicted, said Shabir A Madhi, Dean Faculty of Health Sciences and Professor of Vaccinology at University of the Witwatersrand.
Madhi said that the evolution of the virus has been so rapid that the Delta variant, which is wreaking havoc in some countries and currently dominating the world, is at least twice as transmissible as the ancestral virus that was circulating.
"What this means is that herd immunity is no longer a discussion the world should be having. We should start to avoid using that term in the context of SARS-CoV-2, because it’s not going to materialise – or is unlikely to materialise – during our lifetimes," he writes in an article.
According to WHO, 'herd immunity' is the indirect protection from an infectious disease that happens when a population is immune either through vaccination or immunity developed through previous infection.
WHO says that it supports achieving 'herd immunity' through vaccination, not by allowing a disease to spread through any segment of the population, as this would result in unnecessary cases and deaths.
The professor says that when politicians and others speak about herd immunity, they, unfortunately, think that the current tools available to the world are adequate to eliminate the virus.
"It’s not what we have at hand right now...Instead we should be talking about how to live with the virus. The tremendous success that’s materialised with COVID-19 vaccines allows us to do this, without actually getting into the herd immunity threshold," he writes.
The expert further says that peddling the concept of herd immunity creates a misconception that we are actually going to get to a stage where this virus is going to be eliminated. "That’s unlikely to happen. It will continue circulating," he states.
Underlining the dangers in making people believe that heard immunity is possible, Madhi says that it could dent confidence in vaccines. "Even if South Africa gets to its target of 67% of the population being vaccinated – as set out by the Department of Health – there will still be outbreaks of COVID-19."
"The result will be that people begin to doubt the benefits of being vaccinated. Also, for the now dominant Delta variant, immunity against infection (not only COVID-19 illness) would need to be closer to 84% for the “herd immunity" threshold to be reached," he says.
Madhi adds that failing to face up to the reality that herd immunity can’t be achieved will mean that countries like South Africa will continue to believe that ongoing restrictions will get them there. "That will compromise the lives of people on multiple fronts – including education and livelihoods," he writes.
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