What We Know So Far About the Coronavirus Variants

Just as you're starting to feel a little more hopeful about the pandemic, thanks to the widespread rollout of three vaccines, there's a new boogeyman in town. We're talking about the variants of the novel coronavirus.

A variant means that the virus has mutated, or changed. This may then affect how contagious the virus is or its severity. Some variants simply disappear while others go on to infect the population.

According to the Centers for Disease Control and Prevention (CDC), there are multiple novel coronavirus variants circulating the world. Some are more concerning than others, though, because they may be more contagious.

The World Health Organization (WHO) now refers to these variants of concern using letters of the Greek alphabet. They include variants Alpha, Beta, Gamma and Delta, which were first detected in the U.K., South Africa, Brazil and India, respectively.

"The thing about variants is that they're really to be expected. All viruses change," Patricia Couto, MD, an infectious disease physician with Orlando Health, tells LIVESTRONG.com.

As they replicate in the body, the virus makes more "virus babies," she says, which can cause replication mistakes in its genetic material. Often, this doesn't go anywhere, but sometimes these changes make the virus more easily transmissible from person to person.

In the coronavirus, there may be a small change in one of its spike proteins (the little hooks it has around its surface), allowing it to better latch onto the proteins or receptors of the person to infect them, Dr. Couto explains.

While the CDC notes that research is underway to examine if these variants are more deadly or cause more severe illness, they could still cause more death if they're able to infect more people, Dr. Couto says.

What's more, emerging data suggests that the Alpha variant indeed "has the potential to cause substantial additional mortality compared with previously circulating variants," according to a March 2021 study in ​The BMJ.​

One problem is that there is not a centralized system for analyzing how all of the vaccines perform against all of the variants, John P. Moore, PhD, of Weill Medical College of Cornell University, said in a ​JAMA Network​ interview in early March. What we know right now is from smaller-scale studies, and really, we're piecing together the information as it comes in.

There is also less known about how the Johnson & Johnson vaccine stands up to these variants. In press materials, the company said it offered protection "across countries with different variants." Their trials were conducted in the United States, South Africa and Latin America.

In short, however, the vaccine provides at least some protection against all of the known variants, so you shouldn't skip it. Here's a deeper look:

The CDC says there's no evidence that this variant will affect how well the vaccine works. In fact, data suggests the vaccine from Pfizer is 93.7 percent effective against the Alpha variant, according to August 2021 research in ​The New England Journal of Medicine​.

And a July 2021 preprint study in medRxiv found that both doses of the Moderna vaccine were 92 percent effective against Alpha in Canada. This study still needs to go through peer review, but it's reassuring preliminary news.

There's less concrete data available about how well the Moderna and Johnson & Johnson vaccines stand up against Alpha, but they do indeed provide some level of protection, per the CDC.

This variant has multiple mutations to the spike protein, including N501Y but also E484K, according to the CDC, which may affect vaccine efficacy.

The Moderna vaccine still protects against this variant, although it is slightly less effective, according to the company.

And research estimates that the Pfizer vaccine is 94 percent effective in protecting against the Beta variant, per a July 2021 preprint study in medRxiv (though this study still needs to be peer reviewed).

The nation's top infectious disease official, Anthony Fauci, MD, has also said both vaccines produce immune protection against Beta.

"There is a very slight, modest diminution in the efficacy of a vaccine against it, but there's enough cushion with the vaccines that we have that we still consider them to be effective," he said on the "Today" show on January 25.

Dr. Moore echoed that on ​JAMA Network​. Because these vaccines provoke such a strong antibody response, we should still be able to cope with a modest reduction in efficacy. You're simply going from "strong" to "reasonably strong," he said.

As for the Johnson & Johnson vaccine, ​The New York Times​ noted that while it was found to have a 72 percent efficacy rate in the United States, it offered slightly less protection in South Africa (where the Beta variant originated), with 64 percent efficacy.

The vaccine from AstraZeneca-Oxford (which has not been approved in the U.S.) did not protect against mild or moderate illness caused by this variant in South African clinical trials, ​The New York Times​ reported February 7. The vaccine may protect against more severe cases, but as with the other variants and vaccines, more research is needed as the virus continues to evolve.

This variant is similar to the Beta variant in that it contains both the E484K and N501Y mutations, per the CDC.

Initial news regarding vaccine efficacy is promising. In an April 2021 analysis in ​The New England Journal of Medicine​, data from Pfizer show that the vaccine was similarly as effective against both the Alpha and Gamma variants. (It was "robust but lower" when it came to the Beta variant.)

The Delta variant has been classified as a "variant of global concern" by the WHO. It's the primary variant of concern in the U.S. because it's more than twice as contagious as previous variants, and may cause more severe illness in people who are unvaccinated, according to the CDC.

The August 2021 study in ​The New England Journal of Medicine​ found that the Pfizer vaccine is 88 percent effective in protecting against this variant. And an August 2021 preprint study in medRxiv found that the Moderna shot is 76 percent effective. However, this study still needs to go through peer review.

The vaccine works by stimulating your immune system to make antibodies against different sections of the spike protein, explains Viviana Simon, MD, PhD, professor of microbiology, medicine and infectious diseases at the Icahn School of Medicine at Mount Sinai. And basically, it seems like the spikes in the variants haven't mutated quite enough to escape these antibodies altogether.

In November 2021, the WHO classified Omicron as another "variant of concern." It's not yet clear whether Omicron is more contagious or produces more severe illness than other strains of the virus, though early research suggests that it may more easily re-infect people who have already been sick with COVID-19.

That said, it also appears that vaccinated folks only experience mild illness, and their symptoms are the same those produced by other variants.

And while there's still more to learn about the vaccine's effectiveness against Omicron, it remains the best form of protection against severe illness and death from variants.

While it appears the vaccines remain protective against the circulating strains of the virus, research suggests that the effectiveness of the vaccine decreases over time, per the CDC.

Fortunately, you can get continued protection against the coronavirus variants from a booster shot. (This happens with the flu shot each year; that vaccine is tailored to what is believed will be the dominant circulating strains of the season.)

According to the CDC, everyone over age 18 is eligible to get a booster shot if it's been at least six months since your second Pfizer or Moderna vaccine or two months since your Johnson & Johnson shot.

The CDC also approved a mix-and-match approach to boosters, meaning you can, for instance, get a Pfizer booster shot if you received the Moderna vaccine.

Current research shows that vaccination (including your booster dose) continues to be the best way to protect yourself, reduce transmission and prevent new variants.

The mutations could affect the results of some COVID-19 tests, according to the Food and Drug Administration (FDA). Tests that look for the virus' genetic material that's been altered by the mutation could produce a false-negative result (that's when you're infected, but the test says you're not).

The risk of a false negative is low, according to the FDA, but it could potentially occur with the Accula SARS-Cov-2 Test, the TaqPath COVID-19 Combo Kit and the Linea COVID-19 Assay Kit.

If your doctor uses one of these tests but still suspects you have COVID-19 based on your symptoms and COVID data for your area, he or she may decide to have you take a different test just to be sure.

A variant that's potentially more contagious means it's even more important to keep up all those smart public health practices, like masking up when necessary, washing your hands and, most importantly, getting the vaccine and booster shot.

"Every opportunity to close a door is a good opportunity. Try to hang in there as much as you can and close all the roads for the virus to walk from one person to the other," Dr. Couto says. "The more people doing that at the same time, the greater the chance we have to slow it down."