Making Sense of the COVID Variant Strains

Aaron S. Weinberg MD, MPhil
March 18, 2021
4 min

With the current push to administer millions of COVID-19 vaccines, we’re also hearing more about variant strains of the virus. Some of the headlines seem frightening, especially as questions arise about whether the COVID-19 vaccines will protect us from these new strains. It’s important to remember we are learning more and more about these variants every day. 

Variant Strains Are Common and Even Expected

First and foremost, virus mutations are common, and we, as medical professionals, expected variant strains would occur during this pandemic. Here's a basic explanation of how a variant occurs. 

As a virus spreads it replicates. To do this, it makes copies of its genetic material for offspring viruses to infect other people and continue to spread. As more copies of genetic material are made, errors occur. These errors can lead to mutations. Some mutations have no effect on the virus, but others give it a genetic advantage to invade the host more easily and infect people. There’s also concern this changed virus could become more deadly. After considerable spread, variants are inevitable. It happens every year with a flu virus; it was bound to happen with the COVID-19 pandemic.

We often learn about variant strains after some spread has occurred, which can cause alarm. It’s important to listen to researchers and the medical community to focus your attention on the ones the experts see as having the most potential for concern.

Which Variants Should You Worry About?

There are three primary variants you should pay attention to. They are often referenced by the region where they were first discovered. They are:

  • B.1.1.7: This strain was identified in the fall of 2020 in the United Kingdom, so it’s often referred to as “the UK strain.” Researchers in the United Kingdom believe the variant spreads more easily than the original strain and may be associated with increased risk of death, although worse outcomes are not completely certain. It was first detected in the United States in December 2020 and is expected to be the dominant variant strain in the US.
  • B.1.351: This variant emerged in South Africa in October 2020. The “South African strain” arrived in the US by late January 2021. It shares some mutation qualities with B.1.1.7, but it has not been shown to cause more severe illness, according to Johns Hopkins experts. But there is some concern about higher rates of transmission.
  • P1: Found in Brazilian travelers who went to Japan in early January, this variant may have additional mutations that could make it difficult for our immune system or vaccines to neutralize. The “Brazilian strain” was first detected in the US in late January as well. Some reports are tying it to communities with high re-infection rates in Brazil, but it is still too early to draw firm conclusions.

It's important to note that even if a mutation is not “as deadly,” per se, the fact that it may lead may spread more quickly and easily can lead to more infections. This is concerning for those at higher risk of poor outcomes. Greater spread through ease of transmission makes this population more vulnerable and increases their chances of hospitalizations or death. This is why the medical community is keeping a close eye on the variants found and narrowing its focus on certain ones with the potential to cause the greatest harm.

So far, early research suggests each of the three main variants may spread more quickly than the original viral strain. The concern is that if they do, it could create more cases and add more burden to healthcare systems. While this hasn’t occurred yet, it certainly does hasten the drive for an even more accelerated vaccine roll-out.

What We're Still Learning

We have learned a lot very quickly about COVID-19, but we still have lots more research to do. Unfortunately, that’s also the problem with these new strains. People, understandably, want answers now. A popular question we often hear is: Will the vaccine or past infection with COVID protect me from these variants?

Early research suggests both the Pfizer and Moderna vaccines can provide protection against the South Africa and UK variants. Researchers are also considering a booster shot that could offer even more protection against all three variants. The recently approved Johnson & Johnson vaccine is believed to produce some variant protections as well. The greatest concern is the vaccines potentially being less effective against the E484K spike protein gene mutation found in the South African and Brazilian strains. Let me explain why the concern exists.

When you receive the vaccine or if you’ve had a past COVID infection, you produce an immune response consisting of immunoglobulins made by B-cells and T-cells, which help to attack and neutralize the virus. The immune system is trained to attack the spike protein on the outer surface of the virus. A mutation that changes the way the spike protein looks could fool your immune system and limit the immunoglobulins’ ability to bind to the region. This can decrease effectiveness. It’s analogous to changing your lock, but using the same old key. Research is ongoing and time will tell if the vaccines can prove effective against these strains or not.

The current thinking, however, is that the UK variant is becoming the dominant variant strain in the US, for which there is an early indication of vaccine protection. The CDC continues to track the number of variant cases reported.

It’s also important to remember that when a report suggests reduced effectiveness from a vaccine, results are not conclusive. In addition, reduced effectiveness does not mean zero effectiveness. You may see a drop from 95% protection to 70% or 80%. Again, it’s important to remember, more information is gathered daily, much of it still preliminary. When results are confirmed and the CDC stands behind them, you have a stronger basis for fact.

What You Can Do

As we learn more, the medical community remains optimistic the vaccines will offer protection. At the same time, it’s important to practice the same CDC safety protocols that have kept millions of people safe up to this point. These safe practices, in addition to being vaccinated, will decrease the chances of mutations developing.

Practice social distancing, avoid crowds, wear a mask when you are in public and wash your hands or use hand sanitizer frequently. The CDC is also working with the EPA to confirm that the disinfectants on the EPA’s “List N,” which contains all the products that kill the original strain, also kill the variant strains as well.

And, finally, when it’s your turn to get the vaccine, do it. It’s important to remember that we are all on a mission together to vaccinate the world. We’ve learned that mutations and variants can occur in other areas of the globe and travel easily to us. So, doing your small part locally to vaccinate and practice safety precautions is actually a big part in helping to eradicate the virus and make the world safer for us all.

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Carbon Health’s medical content is reviewed and approved by healthcare professionals before it is published. But note that our knowledge and understanding of COVID-19 are developing and changing very rapidly; if you have questions or concerns about COVID-19 precautions, treatments, and vaccinations, please talk to your healthcare provider.

Aaron S. Weinberg MD, MPhil

Aaron S. Weinberg, MD, MPhil, is Director of Program Development at Carbon Health and triple board-certified in Pulmonary, Critical Care, and Internal Medicine.


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