Geneva: The World Health Organisation (WHO) is monitoring the new Covid-19 strain-- Mu, which has been recently designated as a variant of interest (VOI) for vaccine resistance, the health body has said.
There are four coronavirus variants of concern, as deemed by the WHO, with the Alpha variant -- first recorded in Kent, England -- seen in 193 countries, Beta in 141, Gamma in 91 and Delta in 170 countries.
With the addition of Mu, now there are five variants of interest such as Eta, Iota, Kappa, Lambda and Mu.
Here is all you need to know
Mu, also known as B.1.621, was first identified from Colombia in January this year. Infections from Mu have since been recorded in South America and Europe. Based on the latest round of assessments, B.1.621 was classified as a VOI on 30 August 2021 and given the WHO label "Mu".
The strain has been found to be able to dodge antibodies produced through infection or vaccination, with WHO saying that preliminary data “show a reduction in neutralisation capacity of convalescent and vaccinee sera" although it noted that these findings need “to be confirmed by further studies".
Mu variant has various mutations which indicate that it could be more resistant to vaccines, similar to Beta variant, the WHO said in its weekly epidemiological update on Tuesday.
In terms of how it prima facie looks to be able to beat antibodies, WHO said it was akin to the Beta (B.1.351) variant, which was first detected in and is now the dominant variant in South Africa that was classed as a Variant of Concern (VOC) in December last year. That is also a trait shared by the other variant that has come under the scanner, again in South Africa.
While the global prevalence of the Mu variant among sequenced cases has declined and is currently below 0.1 per cent, the prevalence in Colombia (39 per cent) and Ecuador (13 per cent) has consistently increased, the WHO said.
As of August 29, over 4,500 sequences (3,794 sequences of B.1.621 and 856 sequences of B.1.621.1) have been uploaded to open-access database GISAID (Global Initiative on Sharing Avian Influenza Data) from 39 countries.
These new variants are far from what Delta has become. But the emergence of new strains is of much importance to the scientific fraternity as strains are the virus's response to vaccines. Hence, chances are there that new variants may neutralise vaccines.
Most of the common mutations that make the novel coronavirus more infectious tend to lie in the spike-like structures on its surface, which it uses to invade and latch on to human cells. Antibodies produced by the immune system after a bout infection or as a result of vaccination are geared towards detecting and disabling these spikes. A change in the novel coronavirus’s spike protein can, therefore, potentially render the virus less susceptible to antibodies because it shifts the target so to speak.