South Africa is hit by a fifth wave of Covid due to the new BA.4 and BA.5 variants. The current management of the epidemic could « guide » the world, if these variants spread to other countries as was the case for Omicron, estimates an epidemiologist.
Sandbox of Covid-19 and its variants, South Africa is for researchers around the world a real textbook case on the evolution of the epidemic. Once again the country is preparing to face a new wave, the fifth, carried by new sub-variants of Omicron, explains this Tuesday, May 10 Le Parisien.
In a few weeks, South Africa has seen its number of new infections climb, admittedly at lower levels than during its 4th wave at the end of 2021, but very quickly. Enough to inaugurate « clear signs of a fifth wave in South Africa », said epidemiologist Tulio de Oliveira.
Last November, he was the first to detect with his teams the Omicron variant which shook the whole earth and which today still paralyzes millions of Chinese under health restrictions.
History therefore repeats itself at regular intervals. About every six months, the Covid sweeps over the country, which often serves as a global indicator of the behavior of the virus and its evolution.
Place at BA.4 and BA.5
As Le Parisien reports, South Africa is currently facing new Omicron subvariants. We already knew BA.1 and BA.2, it is now the turn of BA.4 and BA.5 to be under close surveillance by scientists. If these « little ones » of Omicron do not present for the moment any reason to compare them to the original strain or to Delta in terms of dangerousness, they are on the other hand much more transmissible than BA.2, majority at the moment in France, around +20%.
« Don’t be fooled that a new variant would be needed to cause a new wave, Omicron BA.4 and BA.5 are very different from BA.1 as the other variants were from each other », says Tulio de Oliveira. By insisting on this point, the latter evokes the particularities of these two lineages of Omicron.
Summary of BA.4 & BA.5 in South Africa
– 100% of infections
– Fueling 5th wave
– Low testing & high positivity ratio
– Increasing number of hospitalizations, however still much lower than in previous waves
– SA may guide the world on the future of the pandemic— Tulio de Oliveira (@Tuliodna) May 8, 2022
Probability of reinfection
According to the epidemiologist, these two variants present a strong positivity report, a data that measures the percentage of positive cases compared to the number of tests carried out. Thanks to a mutation in their protein spikethe one that allows the virus to cling to our body, these variants are both more transmissible and more prone to evade immunity.
Another point under surveillance concerning BA.4 and 5, their ability to reinfect several times the same person who would have already been infected with BA.1. A study published on May 1, and cited by our colleagues, suggests that unvaccinated people could be even more affected by the risk of reinfection.
With these first elements, Tulio de Oliveira believes that South Africa will « to guide » the rest of the world faced with these new variants. If for the moment they are not very present in France, the current hegemony of BA.4 and BA.5 in « the rainbow nation » will make it possible to establish new rules and a more flexible approach to the Covid epidemic which, with each appearance of a less dangerous but more transmissible variant, is increasingly managed like a flu or other seasonal virus.