Experts say aiming for the moving target of Covid-19 herd immunity may be unrealistic

Experts say aiming for the moving target of Covid-19 herd immunity may be unrealistic, potentially requiring an annual global booster vaccine to fend off emerging variants.

This emerged during a panel discussion hosted by leading managed care provider and medical scheme administrator Agility Health on Wednesday.

Prof Alex van den Heever, health and social security systems specialist at Wits University's School of Governance, said many governments were targeting herd immunity, but that this was unachievable in the same way it was unachievable for flu.

“We are starting [the South African Covid-19 vaccine rollout] in May, and we should have started in January or February. So, it is good that we are rolling out, but it does have consequences that we are rolling out this late,” said Van den Heever, reflecting on the local and global handling of the Covid-19 pandemic, the vaccine rollout and crucial lessons for the third wave and beyond.

Dr Jacques Snyman, clinical development expert for Agility Health in Africa and Agility Risk Solutions in Asia, said while the contexts of vaccine rollout are very different between, for example SA and Singapore, there were lessons to be drawn from the Southeast Asian nation despite it being an island that has simpler logistics to manage.

“What we can learn from them is the speed of decision-making. For instance, when should lockdown be implemented, and the science applied to the decision-making? What is key for me, is that a decision must be made. You cannot postpone a decision during a pandemic,” Snyman said.

Regarding the local delays in securing vaccines, Van den Heever said a number of bilateral agreements were not entered into in 2020 on the basis of cost.

“A number of us did analyses of the costs of the complete vaccination programme. The costs ranged from R7.5bn to reach what was understood as herd immunity at that point, to about R15bn,” he said.

He said that this was well within the capability of SA.

“One of the parts we took into account in terms of the fiscal impact was the fact that all healthcare workers are on medical schemes, therefore their (vaccine) costs would not be for the state,” Van den Heever said.

He said that the Sisonke Programme also made vaccines available to healthcare workers without diminishing state resources.

Prof Sim Mayaphi, head of the department of medical virology at the University of Pretoria and National Health Laboratory Services’ Tshwane academic division, said better planning was needed to prevent the next pandemic.

“At a global level, there is a lesson in pandemic preparedness. This has shown us that the world is not ready for a pandemic. We need to ask critical questions such as could we have predicted this and are our healthcare systems geared for pandemics.

“Surveillance programmes are needed to look at the animal-human interface of viruses and the prevalence of viruses in animal hosts to see if we can predict these viruses being transmitted from host animals to human,” Mayaphi said.

Snyman said the virus mutation likely means that Covid-19 will continue to produce new variants of concern.

“If we are vaccinated this year, this could mean we don’t necessarily have immunity for the strains that emerge next year. Various vaccines are targeting various sites of the virus.

“That particular antibody will only be effective as long as that part of the virus has not mutated. The Johnson & Johnson and Pfizer vaccines are only partially effective, but they reduce the likelihood and severity of illness. Will these vaccines protect us into the future? We simply don’t know. The next strain may not be affected by the antibodies we have vaccinated for. It is therefore likely that long-term vaccination strategies will be required.” said Snyman.

Van den Heever pointed out that developing local manufacturing capacity for treatments to achieve resilience would require production for a wider market to be feasible.

Looking at private-public partnerships and the relevance for the future, van den Heever said that it is a requirement that a country uses its total capacity to care for its people and that governments should embrace and expand their consultative and delivery processes to ensure best outcomes.

“We have the tools, and we should use the tools,” Dr Snyman said.

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