Mu variant, what we know and where it is widespread in Italy and in the world – breaking latest news

L’World Health Organization is monitoring carefully a variant of the coronavirus called Mu o B.1.621 first identified in Colombia last January and spread to Latin America. On 30 August, the WHO added the Mu variant to the list of variants of interest, or those variants responsible for outbreaks in individual countries that have characteristics potentially capable of making the virus more transmissible, or virulent or capable of evading neutralizing antibodies (or all the characteristics together) without yet confirming with epidemiological investigations as it happens for the variants of concern (Alpha, Beta, Gamma, Delta). Mu is the fifth variant of interest currently monitored by the WHO (the others are Eta, Iota, Kappa, Lamba). Most viruses change over time, and although some mutations have little or no impact on the properties of the virus, others can change the way it spreads, its severity, and the effectiveness of vaccines or other medicines. This is why they must be kept under control.

Where widespread

As mentioned, the Mu variant was detected in Colombia in January 2021, where today the prevalence is 39%. It has since been identified in more than 39 countries including the United States (49 out of 50 states), South Korea, Japan, Ecuador, Canada, Europe, United Kingdom. In England, according to the latest report of September 3, no new cases have occurred since August 12. In Italy, 79 cases have been seen since the beginning of the epidemic, just 4 in the last 45 days. In the Brescia area, a cluster involving seven individuals, all travelers from abroad, took place last April. However, the global prevalence is decreasing and today stands at 0.1%.

Do Vaccines Work Against Mu?

It is not yet clear how much protection vaccines offer against this variant. The Mu variant features a constellation of mutations indicating one potential ability to escape immune similar to Beta, WHO said. Mu may be more resistant to coronavirus vaccines than other variants but this needs to be confirmed by further studies. The research available so far is in fact only in vitro: preliminary data indicate a reduction in the neutralizing capacity of sera from convalescent and vaccinated patients, but information on the real world is still lacking. A study published in the Journal of Medical Virology at the end of July by the researchers of the Microbiology and Virology laboratory of the Spedali Civili of Brescia highlighted a significant decrease in the neutralizing activity of vaccinated sera against the Mu variant. Another Japanese pre-print research concluded that the Mu variant is highly resistant to sera from Covid-19 convalescent and vaccinated individuals (in this case with Pfizer). The Public Health England report also points to a certain ability of Mu in reducing the neutralization activity in both convalescent and vaccinated sera, similar to what happens with Beta (South African). The British body however points out the lack of real world data, essential to understand the true extent of a potential immune evasion. Scholars around the world agree that the Mu variant poses no immediate threat at this time. White House virologist consultant Anthony S. Fauci also said the US government is keeping an eye on the variant, which is by no means close to becoming dominant since Delta causes more than 90 percent of the country’s cases. Fauci said that while laboratory data has shown that the Mu variant can evade certain antibodies, including those induced by vaccines, there is currently a lack of clinical data and other research involving people to prove it., Noting that vaccines generally remain effective. and the best protection against the coronavirus.

The most transmissible Mu variant?

The Mu variant appears to be more transmissible than the original strain and in Ecuador and Columbia it was able to beat Gamma and Alpha. But in the rest of the world, bearing in mind that this variant has been in circulation since the beginning of the year, its diffusion is contained and has not spread like Alfa and then Delta. The Mu variant has a number of mutations already observed in other variants. Mu has 21, all located on the Spike protein. Among the most significant mutations are the E484K, an immune escape mutation, (common to Beta and Gamma variants) and the N501Y, known to help the virus bind more tightly to human cells.