In December 2020, news media reported a new variant of the coronavirus that causes COVID-19, and since then, other variants have been identified and are under investigation. The new variants raise questions: Are people more at risk for getting sick? Will the COVID-19 vaccines still work? Are there new or different things you should do now to stay safe?
Stuart Ray, M.D., vice chair of medicine for data integrity and analytics, and Robert Bollinger, M.D., M.P.H., Raj and Kamla Gupta professor of infectious diseases, are experts in SARS-CoV-2, the virus that causes COVID-19. They talk about what is known about these new variants, and answer questions and concerns you may have.
Coronavirus Mutation: Why does the coronavirus change?
Variants of viruses occur when there is a change — or mutation — to the virus’s genes. Ray says it is the nature of RNA viruses such as the coronavirus to evolve and change gradually. “Geographic separation tends to result in genetically distinct variants,” he says.
Mutations in viruses — including the coronavirus causing the COVID-19 pandemic — are neither new nor unexpected. Bollinger explains: “All RNA viruses mutate over time, some more than others. For example, flu viruses change often, which is why doctors recommend that you get a new flu vaccine every year
What is the delta variant?
Since the beginning of the COVID-19 pandemic, the SARS-CoV-2 coronavirus that causes COVID-19 has mutated (changed), resulting in different variants of the virus. One of these is called the delta variant (arising from Pango lineage B.1.617.2). The delta coronavirus is considered a “variant of concern” by the WHO and CDC because it appears to be more easily transmitted from one person to another. As of September 2021, delta is regarded as the most contagious form of the SARS-CoV-2 coronavirus so far.
Here is what you should know:
The CDC recommends that everyone wait until they are fully vaccinated for COVID-19 before traveling internationally. Traveling internationally if you are not fully vaccinated for COVID-19 is not recommended, because it puts you at risk for coronavirus infection, including the SARS-CoV-2 delta variant. This includes unvaccinated children.
- •Delta rapidly became the dominant variant of the SARS-CoV-2 virus in the U.S. in 2021.
- •Unvaccinated adults and children should strictly follow mask, distancing and hygiene safety precautions and avoid international travel if possible.
- Being fully vaccinated for COVID-19 can protect you from the delta variant, but breakthrough infections sometimes occur.
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- While the authorized COVID-19 vaccines are not perfect, they are highly effective against serious coronavirus disease and reduce the risk of hospitalization and death.
- Other vaccines available in other countries may not be as effective in protecting you from the delta variant and other mutations of the coronavirus.
- Although vaccines afford very high protection, infection with the delta and other variants remain possible. Fortunately, vaccination, even among those who acquire infections, appears to prevent serious illness, hospitalization and death from COVID-19.
How many strains of COVID are there?
“We are seeing multiple variants of the SARS-CoV-2 coronavirus that are different from the version first detected in China,” Ray says.
Will the COVID-19 vaccines work on the new variants?
Ray says, “There is evidence from laboratory studies that some immune responses driven by current vaccines could be less effective against some of these variants. The immune response involves many components, including B cells that make antibodies and T cells that can react to infected cells, and a reduction in one does not mean that the vaccines will not offer protection.
“People who have received the vaccines should watch for changes in guidance from the CDC [Centers for Disease Control and Prevention], and continue with coronavirus safety precautions to reduce the risk of infection, such as mask wearing, physical distancing and hand hygiene.”
How are the new coronavirus variants different?
“There’s evidence that some genetic changes in SARS-CoV-2 can result in a more contagious variant,” Bollinger says. “This is particularly true for the delta variant.”
“Researchers have preliminary evidence that some of the new variants seem to bind more tightly to our cells” Bollinger says. “This appears to make some of these new strains ‘stickier’ due to changes in the spike protein and therefore more easily transmitted.”
Are coronavirus variants more dangerous?
Bollinger says that some of these mutations may enable the coronavirus to spread faster from person to person, and more infections can result in more people getting very sick or dying. In addition, studies are underway to determine whether some variants could be associated with more severe disease.
“Therefore, it is very important for us to expand the number of genetic sequencing studies to keep track of these variants,” he says.
Bollinger explains that it may be more advantageous for a respiratory virus to evolve so that it spreads more easily. On the other hand, mutations that make a virus more deadly may not give the virus an opportunity to spread efficiently. “If we get too sick or die quickly from a particular virus, the virus has less opportunity to infect others. However, as we have seen with delta, more infections from a faster-spreading variant will lead to more hospitalizations and deaths,” he notes
Could a new COVID-19 variant affect children more frequently than earlier strains?
Ray says that widespread infection with the delta variant has resulted in an increased number of cases in children, including uncommon severe infections and deaths.
“There is no convincing evidence that any of the variants have special propensity to infect or cause disease in children. We need to be vigilant in monitoring such shifts, but we can only speculate at this point,” he says.
Are there additional COVID-19 precautions for the new coronavirus variants?
Bollinger says that as of now, none of the new coronavirus variants call for any new prevention strategies. “We need to continue doing the basic precautions that we know work to interrupt spread of the virus,” he says.Vaccines are the medical miracle of 2020, but we need to re-emphasize basic public health measures, including masking, physical distancing, good ventilation indoors and limiting gatherings of people in close proximity with poor ventilation. We give the virus an advantage to evolve when we congregate in more confined spaces,” he says.
“In the meantime, we need to continue all of our efforts to prevent viral transmission and to vaccinate as many people as possible, and as soon as we can.”
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