South Africa has recorded 4,000 potential Covid-19 re-infections in 6.7 million laboratory tests its conducted up until 6 January 2021, says Professor Kholeka Mlisana, head of Medical Microbiology Department at UKZN.
In a media briefing on Monday evening (18 January), Mlisana said that a re-infection is recorded when an individual is infected by Covid-19 and the illness subsequently resolves. However, 90 days after the person is declared disease or virus-free they subsequently report a second Covid-19 infection.
Mlisana said that this information is important to track given the second variant of Covid-19 discovered in the country and the possibility that it could drive re-infections.
“Re-infections occur either when there has been an inadequate or short-lived immune response. As a result, when the next bout of infection comes, the individual succumbs to the infection.
“It could also be that the body has not been stimulated to the new variant and immune response and therefore you get re-infections,” she said.
However, based on an analysis of the data, Mlisana said that the re-infections do not appear to be increasing alongside the new variant.
She added that the number of recorded re-infections has increased, but that this is in line with the increase of Covid-19 cases being seen across the country.
Mlisana said that scientists in the country are now working on a study on the new Covid-19 variant and the possibility of re-infections.
Why the new variant spreads faster
Presenting the basic findings on the new 501.V2 variant, chief government advisor Professor Salim Abdool Karim said scientists initially noticed 23 mutations in the virus around November last year.
“We saw in November, 23 mutations in the face of a virus that had been quite stable. What we have seen is not just that this virus has mutations, but it has systematically spread. It has been spreading across our entire coastal region,” he said.
“What we saw is how it quickly came to dominate all the sequences we were doing. In our latest data from KwaZulu-Natal, 59 out of the 61 sequences came up with the new variant. It is now the predominant virus spreading in our midst.”
Karim said South Africa’s second wave of infections reached ‘completely new heights’, driven by this new variant.
Quoting research conducted by scientific bodies, Karim explained that changes in the virus’ amino acids led to changes in the charge and shape of the protein.
He showed that the binding of the virus to the human cell had changed significantly and noted that the virus and its spike protein now rotated about twenty degrees and is, therefore, able to approach more deeply into the binding site.
This means that the virus’s affinity and its ability to bind to the human cell is now stronger and that’s what enables it to become a more efficient virus in the way it transmits.
“This virus is spreading about 50% faster. Our second wave is faster than our first, at least in South Africa’s coastal provinces where we know this variant to be dominant.
“Current data suggests the new variant is not more severe and the published convalescent serum studies suggest that natural antibodies are less effective,” he said.
Hopeful of a decline
In the same briefing, Health minister Dr Zweli Mkhize said that he was ‘hopeful’ of South Africa’s Covid-19 response after the previous week showed promising signs of decline in transmission.
On Sunday (17 January), there was a 23% decrease in new cases nationally compared to the seven days prior, he said.
“This could be attributable to many factors, including enhanced physical distancing facilitated by lockdown regulations.
“We must thank South Africans for adhering to the regulations, difficult and frustrating as it may be. Every sacrifice made has saved lives and we appreciate the patriotism South Africans are displaying to protect the sanctity of life.
However, Mkhize said that there is still cause for concern as the healthcare system continues to experience significant strain.
Hospitalisations continue to trend upwards, showing an 18,3% increase on 16 January compared to seven days prior. As at 16 January, nearly 18,000 (17,878) patients were admitted, with 2,472 in ICU, 1,117 on ventilators and 5,850 requiring oxygen.
“This is a significant additional burden to the system and we must salute our health care workers for their stamina and courage as they continue to battle it out in the forefront.
“We understand the significant risks that you take every day, yet we have witnessed sheer commitment by the professions in health care and a willingness to engage in the pursuit of excellence in health care delivery,” Mkhize said.