5 things you should know about variants
“1. If you’ve ever gotten a flu shot, you’ve already dealt with a virus variant.
Viruses evolve all the time. Unless you work on infectious diseases, the idea of a “variant” might seem new and scary—but there’s nothing particularly unusual about them. Influenza’s ability to mutate quickly (I’ll talk more about this in the next section) is why we get a new flu shot every year. We need to update the vaccine annually to keep up with constantly shifting flu virus strains.
…When the cell is making a new virus, it has to copy those instructions. If you’ve ever had to take a typing class in school, you know how hard it is to retype something without making a mistake. The code for the virus that causes COVID-19 is around 30,000 letters long. That’s a lot of opportunities to mess up—which the coronavirus often does.
Most mistakes lead to a virus that either is functionally identical or can’t replicate. But every once in a while, there’s a change that makes it easier for the virus to infect people or evade the immune system. When that change starts to spread through a population, a new variant emerges.
2. We’re seeing the same mutations pop up again and again. That may be good news.
All viruses evolve, but not all viruses evolve at the same rate and in the same way. Some, like the flu, change rapidly. Others mutate slowly. Fortunately for us, SARS-CoV-2 is in the latter camp. It mutates about half as fast as the influenza virus.
…Compared to influenza viruses—which are made up of eight genetic segments that can be rearranged in lots of different ways—the coronavirus is a much simpler virus. The most notable mutations we’ve seen so far have happened in the same spot: the spike protein that sticks out of the surface of the virus.
…That limited capacity for change may explain why we keep seeing the same mutations appear in different places rather than lots of distinct variations.
Some experts think we may have already seen the most concerning mutations that this virus is capable of.
3. The virus is changing, but the path to ending the pandemic remains the same.
…The good news is that many of the vaccines being used today appear to prevent severe disease, even from the new variants. This is a tribute to how effective the vaccines are in general.
The big question now is whether we need to update the vaccines to target the variants. Regulators and drug companies are working on a modified vaccine that could be out in a couple months if it’s deemed necessary. Here in the United States—where the majority of people will likely be vaccinated by the end of the summer—some people may end up getting a booster shot that protects against additional strains.
For now, the key is to keep following best practices. The best way to prevent new variants from emerging is by stopping transmission of the virus altogether. If we remain vigilant about social distancing, wearing a mask, and getting vaccinated, we will bring the pandemic to an end much sooner.”
4. Variants make it even more important that vaccines are made available everywhere.
The more the virus that causes COVID-19 is out there in the world, the more opportunities it has to evolve—and to develop new ways of fighting our defenses against it. If we don’t get the vaccine out to every corner of the planet, we’ll have to live with the possibility that a much worse strain of the virus will emerge. We could even see a new variant emerge that evades existing vaccines altogether.
5. We can do better next time.
…The tools we’re putting in place to monitor variants in this pandemic will prove invaluable long after the worst of COVID-19 is behind us. Widespread sequencing should be part of any plan to prepare for the next pandemic. If you’re doing enough sequencing and comparing that data with other measures, you can see concerning variants when they first emerge. The earlier you identify a change, the more time you have to study it and, if needed, to tune vaccines and therapeutics to address any changes that have taken place.”