SARS-CoV-2 Variants

 

Since the start of the pandemic, SARS-CoV-2 has undergone many mutations. This doesn’t surprise epidemiologist Katelyn Jetelina:

SARS-CoV-2 is mutating every two weeks due to the high levels of transmission across the globe. Only 36% of the globe is vaccinated with low adherence to public health measures in some countries, which allows this virus to jump from person-to-person at a high rate.

Contrary to misinformation circulating on the web, vaccines do not promote mutations. We actually saw the opposite in a recent study. Scientists looked at the rate in which Delta made small changes as it spread throughout 20 countries between June 20 to July 3 2021. They found that vaccination coverage was inversely related to the mutation frequency. In other words, the more a country was vaccinated, the less fast the virus changed.

 

Facing a strong surge caused by the Delta variant, the United States is an unfortunate exception. Jetelina says this is most likely due to the fact that the mitigation strategies shown to be effective in reducing transmission and illness, hospitalizations, and deaths (masking in public, social distancing, hand washing, avoiding crowded indoor spaces) have been largely abandoned by so many Americans since the last surge was brought under control in the spring. In some states, effective public health measures have been foolishly denied and irresponsibly eliminated by politicians.

Now, Brandon Sapienza introduces us to a brand new strain of coronavirus: the mu variant (B.1.621).

Since being discovered in Colombia in January, the mu variant of COVID-19 has spread to nearly four dozen countries and has made its presence known in Hawaii and Alaska. It has so far been found in 49 states with Nebraska being the only state to not have a mu variant case detected.

Health officials believe mu is even more transmissible that the delta variant and has the potential to resist vaccines.

 

About the prospect that Mu will become the next dominant variant, Jetelina is cautiously optimistic:

Should we be worried? Probably not, but it’s worth watching. There are three broad ways in which a virus will mutate:

1. More transmissible

2. More deadly

3. Escape vaccine immunity

It looks like Mu is mostly #2 (as seen in nursing home deaths in Belgium) and #3. So it’s more deadly and could escape vaccines and medical treatments. Importantly, though, it doesn’t look to be more transmissible than Delta. Because of this, Delta is holding strong and isn’t being pushed away. In fact, the global prevalence of Mu is decreasing, which is a great sign.

 

Adam S. Lauring, MD and Preeti N. Malani, MD point out that the Delta variant wreaking havoc in the U.S. at the present time spreads 100% quicker than the original coronavirus. That makes Delta more dangerous to people who remain unvaccinated, to children under 12 who can’t yet receive a vaccine, and to people with immune system disorders who might not have responded robustly to their vaccinations. And with hospitals buckling as emergency rooms, inpatient units, and ICUs fill up fast with sick, largely unvaccinated COVID-19 patients, Delta also makes the situation more dangerous for everyone else seeking emergency medical care for conditions not related to COVID-19:

Delta (B.1.617.2) is currently the most prevalent variant in the United States. Early data suggest that the Delta variant spreads almost twice as quickly as the original SARS-CoV-2 virus. It is not yet clear whether Delta causes more severe disease. The Delta variant may not be neutralized as well by antibodies in vaccinated people. Early data suggest a small decrease in vaccine effectiveness in patients who are fully vaccinated against SARS-CoV-2. However, individuals who have received only a single dose of a 2-dose vaccine regimen are much less protected against the Delta variant. People who have not received a COVID-19 vaccine are at high risk of becoming infected with the Delta variant because of its increased transmissibility.

 

This destructive and painful pandemic is not even close to being over. Until everyone decides to work together constructively to achieve the same goal of finally getting COVID-19 behind us, public health experts will keep their eyes peeled for the next variant of concern to emerge:

Surveillance programs will continue to monitor for SARS-CoV-2 variants and the possible implications of these variants for disease spread, treatments, and vaccines. Vaccination is safe and remains the most effective way to prevent severe disease and limit spread of SARS-CoV-2.

 

Read about variants of SARS-CoV-2 on the JAMA Patient Page here.

 

source http://www.thepediablog.com/2021/09/14/sars-cov-2-variants/