Everything You Need To Know About the New Coronavirus Variant

The World Health Organization (WHO) has added a new coronavirus variant to its list to monitor. It is called the mu variant and has been designated as an interesting variant (VOI). This means that mu has genetic differences from the other known variants and causes infections in multiple countries, and can therefore pose a particular threat to public health.

It’s possible that mu’s genetic changes make it more transmissible, allow it to cause more severe disease, and better enable it to escape the immune response driven by vaccines or infection with earlier variants. This, in turn, can make it less susceptible to treatments.

Notice the word maybe. A VOI is not a variant of concern (VOC), a variant that has been proven to acquire one of those characteristics, making it more dangerous and thus more consistent. Mu is being closely monitored to see if it should be redesignated as a VOC. We must hope not.

There are four other VOIs that are being monitored by the WHO – eta, iota, kappa and lambda – but none of these have been reclassified as a VOC. That could also be the case with mu, but we have to wait for further data.

What makes mu particularly interesting (and worrisome) is that it has a “constellation of mutations pointing to possible immune escape properties,” what the WHO calls. In other words, it has the characteristics of being able to circumvent existing vaccine protection.

Where does it spread?

Mu was first seen in Colombia in January 2021, when it was given the designation B1621. It has since been discovered in 40 countries, but is currently believed to be responsible for only 0.1% of infections worldwide.

Mu is much more common in Colombia than anywhere else. Looking at genetically sequenced coronavirus samples, 39% of the samples analyzed in Colombia are mu — although no mu samples have been recorded there in the past four weeks.

Mu initially spread in Colombia, although the infections now seem to have cleared up.

In contrast, 13% of the samples analyzed in Ecuador were mu, with the variant accounting for 9% of the samples sequenced in the past four weeks, while in Chile just under 40% of the samples sequenced in the past turned out to be four weeks mu. month. This suggests that the virus is no longer circulating in Colombia, but is being transmitted in other nearby South American countries.

So far 45 cases have been identified in the UK through genetic analysis, and they appear to have come from abroad. Because not all COVID-19 cases are ultimately sequenced to see which variant it is, the prevalence of mu in the UK may be higher.

How dangerous is it?

The main questions are whether mu is more transmissible than the currently dominant variant, delta, and whether it can cause more serious disease.

Mu has a mutation called P681H, first reported in the alpha variant, which may be responsible for faster transfer. However, this study is still in pre-print, meaning the findings have yet to be formally reviewed by other scientists. We cannot yet be sure of the effects of P681H on the behavior of the virus.

Mu also has the mutations E484K and K417N, which are associated with the ability to evade antibodies against the coronavirus – the evidence for this is more concrete. These mutations also occur in the beta variant, and so it is possible that mu behaves like beta, which some vaccines are less effective against.

Mu also has other mutations – including R346K and Y144T – whose effects are unknown, hence the need for further analysis.

But can I really bypass existing immunity? For now, there is only limited information on this, with a study from a lab in Rome showing that the Pfizer/BioNTech vaccine was less effective against mu compared to other variants when tested in a lab experiment. Despite this, the study still considered the vaccine’s protection against mu to be robust. Really, we don’t know yet if mu’s mutations will translate into increased infection and disease.

However, notable reports of mu have emerged. In late July, a Florida news channel reported that 10% of samples sequenced at the University of Miami were mu. In early August, Reuters reported that seven fully vaccinated residents of a nursing home in Belgium had died from an outbreak of mu. However, these are limited snapshots of the variant’s behavior.

What happens now?

Mu is the first new variant to be added to the WHO list since June.

When a variant is identified as interesting, WHO conducts a comparative analysis of the characteristics of the new variant and assesses how it compares to other variants also monitored by asking Member States to collect information on the incidence and effects of the variant. This is currently underway and means Public Health England is keeping a close eye on it.

In Kenya, only 1.5% of people have been fully vaccinated against COVID-19.

The designation of mu as a VOI reflects the widespread concern about the possibility of new variants emerging that may prove problematic. The more transmissible delta variant that is taking hold in many countries, especially among the unvaccinated, shows how quickly and significantly viral variants can change the course of the pandemic.

Every time the virus reproduces in someone, there is a chance that it will mutate and create a new variant. This is a numbers game. It’s a random process, a bit like throwing dice. The more you roll, the greater the chance that new variants will appear. The main way to stop variants is worldwide vaccination.

The rise of mu reminds us how important that goal remains. Many people, especially in developing countries, remain unvaccinated. We need to get vaccines to these countries as soon as possible, both to help the people there who are vulnerable, but also to prevent new variants from emerging. Otherwise, our way out of the pandemic will be delayed, possibly for months.

Written by Luke O’Neill, Professor of Biochemistry, Trinity College Dublin.

This article was first published in The Conversation.