Potency, Thy Name Is Covid-19

Professor Shabir Madhi shares his views at PSG’s latest Think Big webinar

Most South Africans probably think our death rate from Covid-19 is around 50,000 people.  But it is likely to triple this amount based on South African Medical Research Council modelling. This alarming information was revealed by Professor Shabir Madhi at PSG’s latest Think Big webinar this morning

As Professor of Vaccinology at the University of the Witwatersrand and Director of the world-renowned Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit (VIDA), Prof Madhi has access to data and an ability to interpret it that most of us do not.

He told viewers that the official figures are a vast underestimation of reality.  Along with other scientists, Prof Madhi looks, instead, at excess mortality figures.  “South Africa’s excess mortality indicates that more than 150,000 people have likely died from Covid-19,” he told viewers. 

Even if one assumes that only 70% of our excess mortality is due to Covid-19, which would be conservative, South Africa still ranks 11th globally with a mortality rate that is higher than Spain, Italy, the UK and even the US. “This shows how potent the virus is, and how unsuccessful our efforts to contain it have been,” Madhi said.

Janine Johannes, Head of Group Human Resources at PSG hosted the event.  She said, “These figures show how urgently South Africa needs to start vaccinating high-risk individuals.”

But last week, the government put its trial of the Johnson & Johnson vaccination on hold due to a small number of instances where vaccine recipients experienced a rare type of blood clot. 

Discussing these issues, Prof Madhi said that it’s difficult to ascertain who is most at risk, and AstraZeneca and Pfizer probably have had similar rates of the described rare side effects. Those affected range from 4-5 individuals per million. Mortality rates since the pandemic began in South Africa are at 1800 of every million assuming only 70% of excess mortality is due to Covid-19. The risk of dying from Covid-19 is nowhere near the risks of the rare occurrence of blood clots from the vaccines. “In South Africa, we unfortunately don’t have the same luxuries as countries like the US, who can afford to pause a vaccine while another one fills the gap. The lesson here is to truly consider the benefit/risk ratio before taking such a decision.”

Of variants and vaccines

Covid-19 has further expressed its potency by mutating into powerful new variants.  “Until November last year none of the models predicted that there would be significant mutations that would change the trajectory of the pandemic,” said Madhi.

Both the UK’s B117 variant and South Africa’s B1351 variant have an important mutation that makes the virus both more transmissible and more virulent in that once infected, you are more likely to end up in hospital or even die.  To put it in numbers, these variants are about 53% more transmissible and 1.4 to 1.6 times more virulent than the original virus.

South Africa’s B1351 variant has additional mutations that make it relatively resistant to the antibody produced by past infection. “Therefore, the strategy of allowing the population to get to natural immunity by allowing people to contract the virus, won’t work.  Covid-19 simply begins to target that immunity with new mutations.”

The B1351 variant is also relatively resistant to many of the 1st generation vaccines that target the spike protein. This is especially true for mild to moderate infections. 

However, these vaccines will probably be effective against severe disease, and for this reason Prof Madhi is critical of the government’s decision to sell on the AstraZeneca vaccines it acquired earlier this year.  While that vaccine is not very effective against mild to moderate disease caused by the South African variant, it is very likely to protect against severe disease, as suggested by the World Health Organisation and the scientific experts that inform it.

“Selling our AstraZeneca vaccines was a miscalculation by our government; one that has set us back by several months in terms of our vaccination rollout,” Madhi said.

Covid-19 is here to stay

Just as the common flu virus continually mutates, and a new vaccine must be developed each year, so too will SARS-CoV-2 continue to mutate and therefore circulate.

“Covid-19’s rate of mutation caught many scientists by surprise; they weren’t expecting such rapid mutations especially not in key components of the virus that we’re targeting with vaccines.”

Right now, there is another variant that has been identified in Tanzania, which seems to be even more problematic than the SA variant in terms of additional mutations that will probably confer even greater resistance to the vaccines. San Francisco has also identified variants that are relatively vaccine resistant.

“Even once vaccines are rolled out successfully in a given country, unless the global community is vaccinated no one is safe, especially as variants have been shown to disperse fairly rapidly including possibly eventually to countries where there is a high level of vaccination. As a result, Covid-19 is not going to simply disappear.  In fact, I believe it will be with us for the rest of our lifetimes.”

It is about controlling the magnitude of severe disease and the number of people that die. Between 10,000 -11,000 people die from seasonal flu each year in South Africa and Prof Madhi said that if we get to the point where the number of people who die each year from Covid-19 is around the same level, that will be a positive scenario.

In conclusion, PSG’s Johannes said that South Africans will have to get used to uncertainty as it will be with us for years to come.  She said that at least financially, one can mitigate against uncertainty with the help of a skilled financial adviser.

Scroll to Top