The new strain of Covid-19 prompts more questions about whether people can be reinfected with the virus. On Monday night, Professor Koleka Mlisana, the executive manager of academic affairs, research and quality assurance at the National Health Laboratory Service (NHLS), and her team said they have been analysing laboratory data that has been coming in until the 6 January. By then, more than 6.7-million tests had been conducted, and more than 1.1-million cases confirmed.
Mlisana and her team of researchers have found that there is a constant risk of reinfection.
“We had more than 4 000 potential reinfections. We don’t know who actually gets reinfections, what drives reinfections, and we are trying to understand why we are getting reinfections. Might it be because of the new variant or not?” she queried.
Mlisana added that despite there being a constant risk of infection, as shown by the current data, there is no indication that the risk of reinfection has increased as a result of the new variant.
The reinfection data is analysed from individuals who had previously tested positive and had been given 90 days to be disease-free.
Meanwhile, in a Monday evening statement, the National Institute for Communicable Diseases said that people who have recovered from Covid-19 are usually protected from being infected a second time.
“This is because they develop neutralising antibodies that remain in their blood for at least five to six months, maybe longer. These antibodies bind to specific parts of the spike protein that have mutated in the new variant. We now know that these mutations have allowed the virus to become resistant to antibody neutralisation,” the statement read.
“The blood samples from half the people we tested showed that all neutralising activity was lost. This suggests that they may no longer be protected from reinfection. In the other half, the levels of antibodies were reduced and so the risk of reinfection is not known. It is, therefore, important that people who have previously had Covid-19 continue to adhere to public health measures.”
Since discovering the new strain of Covid-19 on 18 December, it had been feared that the virus would affect more patients severely. Yet, almost a month later, new evidence presented has shown that the 501Y.V2 strain’s severity is no different to the strain identified during the first wave of the pandemic.
At Monday’s virtual briefing hosted by the Department of Health eight of South Africa’s top scientists, led by professor Salim Abdool Karim, presented their latest findings on this new strain, intending to help people to understand the variant’s significant implications for the county’s epidemic.
The 501Y.V2 variant has led to a rapid rise in the number of positive cases, hospital admissions, and a rise in the mortality rate. In the Western Cape alone, the spread 50% faster than it did during the first wave. From taking up to 107 days to reach 100 000 cases in the first wave, it took only 54 days in the second wave, meaning the virus is spreading at twice the speed.
“This conglomerate that we see, in terms of new cases, increasing admissions and deaths. Is a telling factor in what we are observing in the second wave,” said epidemiologist and infectious diseases specialist Karim.
Yet, despite the new variant spreading faster, current evidence shows that its severity is no different to the first wave’s variant. Based on analysis of the data, the experts said there was no notable difference in the percentage of hospital admissions and the risk of dying in the first and second waves.
“The current data indicates that the virus is not causing more severe disease, but is putting huge pressure on hospitals, and we may see increased deaths just from the lack of hospital beds and pressure on the healthcare system,” said Karim.
The new strain prompted questions about whether the current Covid-19 vaccines would still be effective against variant 501Y.V2.
According to Karim, there is no evidence that approaches to vaccination should be changed.
“In my view, the answer is no, not at this stage; not with the evidence that we have at this point, he said. “Vaccines like we see with Pfizer and Moderna, with 95% efficacy, are among the most effective vaccines that we have for any disease. We are certainly looking at vaccines with high efficacy, and they achieve a critically important goal, which is, they reduce clinical illness and hospitalisation.”
A decline in transmission is becoming evident in SouthAfrica, with a 23% decrease in new cases nationally compared to the previous seven days.
Hospitalisations are, however, continuing on an upwards trend, as reported by the Health Minister Zweli Mkhize.
“The healthcare system continues to experience significant strain with hospitalisations continuing to trend upwards, showing an 18.3% increase on 16 January compared to seven days prior. Nearly 18 000 patients were admitted, with 2 472 in ICU, 1 117 on ventilators and 5 850 requiring oxygen,” he said.