Covid-19 herd immunity: political pandering or realistic resolution?

Those pinning their hopes on herd immunity being the answer to their Covid-19 prayers will be disappointed to learn that this is unlikely to occur anytime soon. 

The term herd immunity has been misconstrued ever since UK Prime Minister Boris Johnson’s announcement that the country would take a slightly different route in combatting SARS-CoV-2, and experts warn that this might be a very dangerous course to take.

Johnson’s plan is to curb the virus, but not completely, allowing people to get sick, recover and hopefully become immune to the virus. 

The White House in the US has embarked on a similar course, opting to allow Covid-19 to spread in healthy, young populations, as a way of protecting vulnerable people. 

This is especially relevant as the northern hemisphere moves into winter.

Europe is third in the world in Covid-19 infections, with 7,108,781 cases confirmed. The UK has 617,692 confirmed cases and 42,875 deaths. 

The Americas are at the top of the global infection list, with 18,090, 384 confirmed cases. The US has more than seven million confirmed cases, and 213, 626 deaths. 

Herd immunity and vaccines  

Relying on herd immunity is a risk though, especially considering that this would require a large percentage of the proportion of the population to have been vaccinated, explained Stellenbosch University biostatistical and epidemiology department’s Professor Peter Nyasulu. 

He said herd immunity can only be reached when there is a vaccine, and when 59% to 68% of the population have been infected and become immune. 

With a vaccine, Nyasulu said 60% to 70% of the population must be vaccinated to achieve herd immunity. 

At the moment, he said South Africa only has about one million infections, in a population of over 50 million.

University of Cape Town (UCT) epidemiologist Professor Landon Myer agreed, and explained that politicians using herd immunity as a strategy to assure voters is appealing, but not exactly accurate. 

At present, Myer said herd immunity “doesn’t look like it plays out in Covid-19.” 

He provided the example of herd immunity in measles, explaining that 94% of the population had to be vaccinated. “We’re a way off from that kind of coverage with Covid-19,” he said. 

This was supported by UCT epidemiologist Maia Lesosky, who said the concept of herd immunity is “only one that is relevant to vaccination,” but is a concept that is being dangerously misunderstood. 

This could lull people into a false sense of security, when in fact, in order to prevent a high mortality rate in the inevitable second wave South Africa is currently bracing for, personal protective measures such as wearing masks, washing hands and social distancing, are crucial. 

Second wave hopefully ‘not so bad’

Nyasulu warned that countries that have relaxed lockdown regulations have experienced a second wave of Covid-19, but that when people follow prevention strategies, transmission rates are “relatively reduced”. 

“If we continue minimising contact, we will defeat the massive upsurge.”

Myer predicts South Africa’s second wave will result in an uptick of cases, but that there could be reduced mortality, in part because vulnerable people and those with co-morbidities had already perished in the first wave. 

“But that doesn’t make the infection any less serious for a vulnerable person, but it means there’s an opportunity for health services to open up, and to return to business as usual. While remaining vigilant,” he explained. 

Myer predicts Covid-19 will circulate for at least another six to 12 months, until a working vaccine is created. 

Hopes for a virus vaccine have helped propel stock markets higher. AFP/File/EVA HAMBACH

Scrapping lockdown? 

Around the world, Covid-19 threatens to reverse decades of initiatives trying to curb poverty and disease, and has caused disruptions in health services.

The World Health Organisation (WHO) found 68% of countries reported disruptions in health checks for children and immunisation services, 63% reported antenatal disruptions, and 59% experienced disruptions in post-natal care. 

93% of countries in a WHO survey reported disrupted or halted critical mental health services. Children have missed precious study time by being kept out of school, and those suffering from serious conditions have had to put treatments on hold.

Myer said an unenviable balancing act between lives and livelihoods would have to continue for as long as Covid-19 is with us. 

He was in agreement to reopen 95% of the economy, while adhering to protective measures, but also agreed that the 5% that remains closed, the “fringes” of the economy, such as nightclubs and concert venues – are closed for good reason. 

This is because they are called “super-spreaders”, referring to large groups of people in a small space, and will have to be reopened in a different way, and not at full capacity. They are also not essential to society at present. 

Nyasulu explained that the drive of the infectious virus is contact, and that as long as contact is minimised, so is the spread, which would eventually “die out in the population.”

“For now, we will still have this for a while, as we are far from achieving these public health preventative measures.” 

Can we handle the economic fallout?

The economic challenges stemming from the continued closure of sections of the economy could result in devastating consequences for the health sector. 

“A recession is bad for public health, and for Covid-19. Which is worse – economic downturn and depression, or the Covid-19 pandemic? We are coming close to the point of recession,”  Nyasulu said.

“Lockdown seems not to be the way to go where many people also suffer economic challenges.”

A recent petition, dubbed The Great Barrington Declaration, was created by a group of epidemiologists and public health scientists with “grave concerns about the damaging physical and mental health impacts of the prevailing Covid-19 policies.”

The group has recommended a “focused protection” approach, which involves allowing those at minimal risk of death to “live their lives normally to build up immunity to the virus through natural protection, while protecting those who are at highest risk.” 

Similar to the US and the UK’s strategies, a focused approach aims to open up the economy, and by proxy the health sector, until a vaccine is created, or until herd immunity is reached. 

Compelling arguments for and against lockdown continue to be presented, but in sub-Saharan Africa, Myer said it is not yet known whether the continent’s comparatively low death rate is due to robust health sector responses, or because of a younger population average than the rest of the world. 

What is known is that the interventions that were instilled worked, however inconvenient and disruptive. We know that in South Africa, instilling health interventions among the general public has had a significant impact. 

The future of public health initiatives and a continued lockdown is subject to change too, with there still being much we do not know about the latest pandemic.

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