DAILY MAVERICK WEBINAR

Covid-19 may have already infected 20 million in South Africa, says Prof Madhi

By Estelle Ellis 14 September 2020

Professor of Vaccinology at Wits University Professor Shabir Madhi, left, and Maverick Citizen editor Mark Heywood. (Photos: supplied | Leila Dougan)

Up to 40% of people living in SA’s densely populated areas had probably been infected by the coronavirus, vaccinologist and member of the Ministerial Advisory Committee, Professor Shabir Madhi, said during a Daily Maverick webinar on Sunday.

Between 35% and 40% of people living in densely populated areas in South Africa had probably been infected with the coronavirus, the latest figures available for the Western Cape and Gauteng show.

The number of people who were infected was way above the confirmed figure of 650,000; “it is more in the region of 15 million to 20 million”, Madhi said. “Nobody could have predicted what would happen in South Africa.” 

Madhi said that initial infection models estimated that about 25% of the population would be infected. He said the high prevalence of infections did not, however, translate into high rates of hospitalisations and deaths.

About half of the confirmed number of cases in SA had been confirmed by private sector laboratories, but the private sector does not look after 50% of the country’s population. He added that the asymptomatic and mildly symptomatic also didn’t get tested.

“The numbers [35% to 40%] are based on antibody testing,” he said.

He added that at the peak of the outbreak the country was reporting about 14,000 cases a day, but the new models show that there were between 60,000 and 80,000 new cases a day.

“While the number of deaths is probably an underestimate… we haven’t seen the infection rate translate into hospitalisation and deaths. It did not transpire to the extent that modellers predicted.” 

He said that using the Western Cape as a benchmark, while there had been about 15,000 confirmed deaths caused by Covid-19 in South Africa, the actual number was likely to be about 30,000.

“Not everyone who has died has been tested for Covid-19. We must appreciate that there had been many deaths outside of hospitals. If we use the Western Cape as a benchmark and use the same adjustment – we think roughly 30,000 rather than 15,000.”

Providing reasons hospitalisations and deaths were relatively low for a country that had such a high number of infections, Madhi said the theory he favours is that South Africans had an “underpinning immunity, probably because of exposure to common cold coronaviruses”. He said this would have offered a cross-protective immunity against the virus that caused Covid-19.

Other theories, Madhi said, are based on the relative youth of South Africa’s population and preventative measures, like lockdown and the wearing of masks, that could have offered some protection.

“We don’t know which of these reasons contributed to us not experiencing [the number of] deaths and hospitalisations [that were expected].” 

Madhi cautioned that the country was not out of the woods yet. “We have reached a threshold [of infections to create] herd immunity.” He warned that these levels were not high enough to allow for all restrictions and non-pharmaceutical interventions such as the wearing of masks, physical distancing and hand-washing to be dropped.

“It will be premature to go back to an open society.” 

He said all the indications currently showed that the country was on a downward trajectory, in terms of new cases, hospitalisations and the number of confirmed deaths. He added that he would still strongly advise against mass gatherings as they could lead to renewed outbreaks.

“[Mass gatherings] are exactly what will allow for superspreading. We will see a much quicker resurgence… many infections over a short period of time.”

But, Madhi added, there was no longer a medical reason to keep SA’s borders closed.

“Having a few visitors is not going to lead to massive outbreaks moving forward. Visitors will not be the reason if they adhere to non-pharmaceutical interventions. We are not trying to contain viral transmission in South Africa, which is when we need border closures.”

He said he did not believe that the quarantining of foreign visitors was necessary. “We don’t quarantine close contacts of South Africans who tested positive. There is almost no reason to put incoming visitors in quarantine. Right now it is a waste of money.”

He said if the country dropped its levels of adherence to non-pharmaceutical interventions, there would probably be a resurgence. “But it will be less severe this time round.”

While this was difficult to predict, as it depended on how complacent people become about masks, hand-washing, physical distancing and mass gatherings, Madhi said emerging patterns in European countries showed a surge in infections after the summer holidays. 

“We might see less compliance in December, meaning that come January and February we might see a resurgence.”

He added: “The reality is that people do become reinfected. There is nothing unusual about it. The reason you recovered the first time was that you developed an immune response. One of the challenges with this virus is that we do not know how long this immunity will last.”

On Wednesday, South Africa paused its trial of the vaccine developed by Oxford University and AstraZeneca after a participant in the UK fell ill, but Madhi said on Sunday that the suspension has been lifted.

“We have concluded that it was unlikely that the adverse event was related to the vaccination.” 

He said the South African part of the trial will be resumed after a review by an ethics committee and the South African Health Products Regulating Authority.

“That is where we stand. We have enrolled 1,800 of the 2,000 that we are targeting. We would have completed [the enrollment] last week if we did not suspend the vaccinations.”

He said when the vaccine was proven to be effective it could be recommended for use under an emergency exemption that allows for vaccinations to be introduced before being licensed by a regulatory authority.

The best-case scenario is that the country will have 10 million doses of the vaccine by June next year, but this will require a significant commitment from the government.

“I think the government is raising its hand and buying into the concept,” he said.

It was, however, unlikely that the virus would ever be eradicated, Madhi added. 

“The best-case scenario for us is that it becomes a seasonal virus with sporadic outbreaks. It is extremely unlikely that we will get to elimination. Some of these respiratory viruses have been circulating since the 1960s. Segments of the population will always remain vulnerable. We don’t know how long immunity will last.” 

He said the health consequences of lockdown must also be addressed with great urgency, explaining that about 12,000 excess deaths due to natural causes recorded this year were a consequence of stringent lockdown rules.

“Deaths due to the diminished management of TB and HIV will roll over to next year or the year after that,” he said.

“We have seen a 25% decline in vaccinations. We will have to figure out how to reverse this. Lockdown came at a cost.” DM/MC

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  • There must be multiples of people that had this and never knew and were never tested. For the vaccine trial, presume they don’t vaccinate people that have antibodies from having had covid? So when the world has a virus, will people first undergo antibody testing? We have had positive and negative PCR tests in our family and both have antibodies : so two of our PCR tests were false negatives!

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