Covid-19 Mu variant not yet detected in SA
NO cases of “Mu”, the recently classified PANGO lineage B.1.621 variant of interest (VOI) have been detected in South Africa yet, the National Institute for Communicable Diseases (NICD) said.
The variant was first detected in Colombia in January, and has since spread across North America, South America and Europe, with some detections in Asia.
“The majority of the Mu sequences (5 123) have been detected in North America (55%), followed by South America (23%), Europe (18%), and Asia (0.1%).
“As at September 3, there have been no cases of Mu detected on the African continent, including South Africa. Currently, it accounts for less than 1% of the globally circulating viruses, with Delta accounting for 88%,” the organisation added.
The mutations within the spike protein, that define Mu, have been seen before in other VOIs or variants of concern (VOCs), including Beta and Delta.
“Some of these mutations have previously been associated with decreased antibody responses and increased transmissibility. This variant will likely, therefore, have similar properties to other variants, with increased transmissibility and reduced sensitivity to antibodies in vaccines and those who have recovered from Covid-19,” the NICD cautioned.
Vaccines currently being used in the country had high levels of protection “against severe disease, requiring hospitalisation and death, even against VOI/VOCs such as Beta and Delta and, therefore, will likely also protect against Mu,” added the NICD.
South African Medical Research Council director of the HIV Prevention Research Unit Professor Ameena Goga said they would have to investigate whether current vaccines induce a robust antibody response.
“According to the NICD, we have no cases with the Mu variant, but we will have to be vigilant and ensure ongoing genomic surveillance. We will have to investigate whether current vaccines induce a robust antibody response, neutralising antibody response and T-cell responses against the Mu variant. Data, thus far, shows that vaccines are still effective against the Beta and Delta variant, and that T-cell responses are preserved, regardless of variant.
“The research agenda needs to move forward to develop a vaccine that is not only based on the spike protein – a variant vaccine is needed to induce robust immune responses, independent of the spike protein, and thus regardless of mutations and variants of concern,” said Goga.
The World Health Organization (WHO) last week said that the Mu variant has a constellation of mutations, that indicate potential properties of immune escape.
“Although the global prevalence of the Mu variant, among sequenced cases, has declined and is currently below 0.1%, the prevalence in Colombia (39%) and Ecuador (13%) has consistently increased,” said the WHO.