Once again, some of the latest headlines about the ongoing COVID-19 pandemic are alarming: Another variant of the virus is now on the rise in the United States.
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“Although this is concerning, it’s not surprising — we’ve been watching for this and more or less expecting it,” explains microbiologist and pathologist Daniel Rhoads, MD.
As scientists and public health experts work to better understand what impact these new variants will have on the course of the pandemic, here’s what we do and don’t know so far.
How many variants are out there?
Variants are fairly normal occurrences. As they pop up, some will fade away. Others can become potential threats. Right now, there are about four “variants of concern” in the U.S. These variants are labeled as such because they have increased rates of transmission. They can also lead to increased hospitalizations or deaths, major reductions in the neutralization of viruses by antibodies or reductions in the effectiveness of treatments or vaccines. It might also be a little harder to detect variants of concern.
As of right now, there are four variants of concern: alpha, beta, delta and gamma. These are being closely monitored by the Centers for Disease Control and Prevention (CDC) and other federal agencies.
How the variants are named
As for their names, the World Health Organization (WHO) decided to use the letters of the Greek alphabet to label the key variants of COVID-19. This system makes things easier to understand and helps prevent misreporting. It also can help eliminate stigmatizing and discriminatory labels that people often use when they refer to variants by their places of origin.
Why the delta variant is alarming
The variant now causing concern around the world is the “delta” variant. Experts say a particular strain of the delta variant (a mutated version of the variant that is more infectious) is responsible for the recent surge of cases in the United Kingdom.
This strain, B.1.617.2, is currently the dominant one in the U.K. and is labeled as a “variant of concern” by the WHO. The main reason for the concern: Experts believe it to be up to 60% more transmissible than the original strain of COVID-19.
While research is ongoing, early data also suggests that this particular variant could be one of the driving forces behind the enormous surge in cases – and, subsequently, COVID-19 deaths – in India in the spring.
In the United States, the CDC recently classified the delta variant as a “variant of concern” due to an ongoing increase of cases. In mid-May, it accounted for only 2.5% of U.S. cases but by mid-June, that number increased to at least 6%, according to the National Institute of Health.
“As of August 2021, the delta variant has become the predominant lineage of SARS-CoV-2 circulating across the U.S. It has caused substantial morbidity. For example, COVID-related hospitalizations in Florida have surpassed previous records due to the delta wave,” says Dr. Rhoads.
How delta variant symptoms are different
With COVID-19, the common symptoms are:
- Fever or chills.
- Shortness of breath or difficulty breathing.
- Muscle or body aches.
- New loss of taste or smell.
- Sore throat.
- Congestion or runny nose.
- Nausea or vomiting.
With the delta variant, the symptoms seem to be a little milder. There have been fewer reports of loss of smell and cough and more reports of symptoms like headache, runny nose, sore throat and fever.
Delta variant symptoms in children have been mild as well. They include:
- Runny nose.
- Upset stomach.
While this recent strain hasn’t caused a lot of severe illnesses so far, some children’s hospitals have reported increasing hospitalizations due to the delta variant.
How does a virus mutate?
While the idea of a virus mutating might sound scary, it’s actually quite normal. Viruses mutate constantly. This is especially true of viruses that contain RNA as their genetic material, such as coronaviruses and influenza viruses.
All viruses are made up of a bundle of genetic material (either DNA or RNA) that’s covered by a protective coating of proteins. Once a virus gets into your body – usually through your mouth or nose – it latches onto one of your cells. The virus’s DNA or RNA then enters your cell, where it can make copies of itself that go off and infect other cells. If the virus can copy itself and hijack enough of your cells without being wiped out by your immune system, that’s how you get sick.
Every now and then, an error occurs during the virus’s copying process. That’s a mutation.
Most of the time, mutations are so small that they don’t significantly affect how the virus works, or they make the virus weaker, Dr. Rhoads says. But occasionally, a mutation helps the virus copy itself or get into our cells more easily.
“If these advantageous genetic mistakes are included when the virus replicates, they’re passed on and eventually become part of the virus’s normal genome,” Dr. Rhoads explains. We can see these mutations accumulate over time, and that’s how we get new variants of a virus strain.
If you get confused about strains, variants and mutations, think of it this way: New variants of a virus strain emerge through the process of mutation. In the media, the words strain and variant are often used interchangeably.
What do we know about other COVID variants?
The delta variant is just the latest one to cause concern in the U.S. as it spreads across the globe. Earlier this year, more infectious variants from the U.K., South Africa and Brazil made headlines as they became more dominant in different parts of the world.
Each has its own set of mutations, but they all contain small changes to parts of the spike protein that helps the coronavirus attach to our cells.
“This is concerning, because it means the virus could spread more easily,” Dr. Rhoads says.
It’s hard to measure exactly how much of an impact new variants initially have on the pandemic since many factors contribute to how quickly a virus spreads – including human behaviors.
But those concerns over the new delta variant are for good reason. The U.K. variant that alarmed experts in the U.S. at the beginning of the year, called B.1.1.7 or “alpha,” now accounts for nearly 70% of all U.S. cases. And the variant from Brazil, P.1, accounts for over 11% of all U.S. Cases. The CDC considers both “variants of concern,” notes Dr. Rhoads.
There is good news, though, as a study out of England showed that the Pfizer vaccine was still highly effective (88%) against symptomatic disease from the delta variant. “These new variants can also still be detected with our current tests, so that’s one thing that should be reassuring,” Dr. Rhoads adds.
What about the lambda variant?
With the delta variant emerging as a dominant variant of concern, the scientific community is working hard to track down the next variant that could possibly make COVID-19 even harder to beat. One variant of interest is the lambda variant (C.37). The earliest documented samples of this variant were recorded back in December of 2020 in Peru. It has since been reported that this variant is more resistant to vaccines and highly infectious. The WHO made it a “variant of interest” on June 14 and it has been detected in 29 countries so far. However, there are still many unknowns when it comes to the lambda variant. Dr. Rhoads says this variant is on the radar, but it’s still too early to determine its impact.
Does the vaccine protect against variants?
In the end, the shape-shifting nature of the coronavirus (and all viruses) is something that experts across the world are keeping a close eye on, but it’s not something you should expect to change the course of the pandemic overnight.
However, the contagiousness of the newer variants is all the more reason to stay careful even as most states roll back social distancing guidelines. Only half of U.S. adults are fully vaccinated but, in many states, that number remains below 50%.
The CDC says the COVID-19 vaccines that are authorized for emergency use (Moderna and Johnson & Johnson) or fully approved (Pfizer/BioNTech) in the U.S. are highly effective at preventing severe disease and death even with the Delta variant. And while breakthrough infections will occur, the number of cases that result in serious illnesses, hospitalizations or death are very low.
“These new waves of infections show that the pandemic is not close to being over yet,” Dr. Rhoads says. “At this time, vaccination has proven to be our most effective tool, and vaccines are readily available for many children and adults in the U.S. Vaccinations are our best defense against these emerging mutations.”