Mu variant confirmed in B.C.

According to the B.C. Centre for Disease Control's latest weekly update on variants of concern and variants of interest, there has been 46 Mu cases detected since June, including two in the most recent week.

Vancouver Sun 5 minute read September 12, 2021

Dozens of cases of the Mu COVID-19 variant — recently declared a variant of interest — have been identified in B.C.

According to the B.C. Centre for Disease Control’s latest weekly update on variants of concern and variants of interest, there have been 46 Mu cases detected since June, including two in the most recent week.

Even before the World Health Organization declared the B.1.621 variant a variant of interest and named it Mu on Aug. 30, the B.C. centre had been keeping an eye on it through its whole genome sequencing system. In B.C., every positive COVID-19 test result is further analyzed to see whether it is a variant of concern, a variant of interest or an emerging variant.

The highly contagious Delta variant of concern that has taken over the world now accounts for close to 100 per cent of all cases in B.C. Other variants of — Gamma, Beta, Alpha and other — are now mostly non existent in the province.

While the Mu variant is in B.C. in relatively very low numbers, it’s worth keeping an eye on. Here are some things to know:

Where did it come from?

Mu was identified in Colombia on Jan. 11, 2021, and has now been found in 31 countries.

It is the most recently recognized variant of interest, joining Eta (B.1.525), Iota (B.1.526), Kappa (B.1.617.1) and Lambda (C.37).

Colombia experienced a huge COVID-19 surge from March to August 2021 that peaked at 33,594 cases a day on June 26, 2021.

Although the Gamma VOC was dominant in Colombia during the initial phase, the Mu VOI outcompeted all other variants, including the Gamma VOC in May 2021, and has driven the epidemic in Colombia since then.


How dangerous is it?

According to the WHO’s COVID-19 Bulletin published last week, Mu has caused some larger outbreaks in South America and Europe. While the number of genetic sequences identified as Mu have fallen below 0.1 per cent globally, it represents 39 per cent of variants sequenced in Colombia and 13 per cent in Ecuador, places where its prevalence has “consistently increased,” WHO reported.

The global health agency said it continues to monitor Mu for changes in South America, especially in areas where it is co-circulating with the Delta variant.

Maria van Kerkhove, head of WHO’s emerging diseases unit, said circulation of Mu is decreasing globally but needs to be observed closely. In a press briefing last week, White House chief medical adviser Dr. Anthony Fauci said U.S. officials are watching it, but so far Mu is not considered an immediate threat.

Here’s what the latest study says

Last Tuesday, researchers from universities in Japan released a study, which has not been peer reviewed, showing the Mu variant had the ability to evade antibodies and vaccines. The study found Mu was “highly resistant” to antibodies in blood samples from COVID-19 survivors and from people who had received a Pfizer or Moderna mRNA vaccine.

According to the research team, the spike used by the new variant to break into cells was more resistant to neutralization than all other recognized variants of interest and variants of concern.

But Dr. Eric Topol of the Scripps Clinic in California — who was not involved in the research — stated a day later that Delta’s high infectiousness surpassed Mu’s ability to avoid antibodies.

What is next?

According to a Reuters report, getting more people vaccinated against COVID-19 is critical, as large groups of unvaccinated people give the virus more opportunity to spread and mutate.

That effort must be stepped up to keep variants from emerging unchecked among the populations of poor nations, where very few people have been inoculated, experts say.

B.C. is well ahead of the pack internationally, with 78 per cent of residents aged 12 and over already fully vaccinated.

During the week of Sept. 2-8, unvaccinated people made up almost 82 per cent of all hospital admissions with COVID-19 in B.C.

This shows that while the current vaccines prevent severe disease and death, they do not block infection. The virus is still capable of replicating in the nose, even among vaccinated people, who can then transmit the disease through tiny, aerosolized droplets.

Defeating COVID-19 will likely require a new generation of vaccines that also block transmission of new variants, says Dr. Gregory Poland, a vaccine developer at the Mayo Clinic in the U.S. Until then, Poland and other experts say, the world remains vulnerable to the rise of new coronavirus variants.


It’s not the only one

The original COVID-19 virus that took hold in Wuhan, China, in late 2019 is now just an incredibly significant footprint in the viral sands of time. It’s now simply the “wild” COVID-19 virus and has been surpassed by many mutations and variations and is not found in B.C.

As of September 2021, the WHO has defined four variants of concern, but on top of that, the BCCDC also monitors Epsilon (identified in California), Zeta (identified in Brazil), Theta (identified in the Philippines) and various other variants of concern and variants of interest.

— with files from Reuters