Coronavirus variants: what you need to know

If you’re paying attention to recent news reports about the coronavirus pandemic, you’ve heard public health officials say they’re happy with the reduction in cases and mortality from vaccinations in the United States. Let’s do it. We were also concerned that the continued spread of delta variants could reverse some of these benefits.

What is a Delta Variant? Furthermore, what is a variant? And how much do we need to worry about any of them?

Here are some questions and answers.

What is a variant?

A variant of the virus is mutated in a way that enhances its spread or severity compared to the original strain that emerged in Wuhan, China. “RNA viruses like coronavirus can mutate when they replicate, especially when they circulate at high speed,” said Monica Gandhi, a professor of medicine at the University of California, San Francisco.

According to Gandhi, the coronavirus Don’t mutate easily Like the flu virus. Still, the coronavirus mutates over time. Different mutants generally cause the same range of symptoms as the original strain of coronavirus. However, mutations may help the virus spread more effectively from person to person, or may benefit from sneaking through either natural or vaccine immunity.

What variants are available in the United States?

Public health authorities Point out In addition to the four “Mutants of Concern”, seven other “Mutants of Interest” that are not yet considered to be as worrisome as the “Mutants of Concern”. Some of the three official categories are of most concern — “Critical Result Variants” —but this type of variant has not yet emerged.

All four “variant of concern” are in circulation in the United States, but some mutants have narrowed their reach and others have increased (World Health Organization said earlier this year. Decided to name the variant after the Greek letter. Discuss and limit the stigma from having a variant named after the country.)

The· Alpha variant First discovered in England. This variant is thought to be about 50% more human-to-human than the original strain. Babak Jabido, a professor of medicine at the University of California, San Francisco, said the alpha mutant was accused of a massive coronavirus surge in the UK in the fall of 2020, which declined only after the blockade. Alpha was also the most common variant in the United States for most of the year, but if the delta variant hasn’t passed yet, it’s about to pass.

The· Beta variant First discovered in South Africa. Like the alpha variant, the beta variant is believed to be about 50% more infectious than the original strain. But it does not secure an important foothold in the United States.

The· Range variant It appears most aggressively in Brazil and is thought to be more contagious than the original strain of coronavirus, but the amount is unknown. Gamma variants did not provide an important foothold in the United States, but they are more prevalent in the United States than beta variants.

At the end, Delta variant Was identified in India and was the driving force behind India’s surge in case rates in the spring of 2021. The delta variant is considered to be more contagious than the other three variants on this list. It took only a few months for the Delta variant to knock it off its perch after the Alpha variant became dominant in the UK in March 2021. This suggests that the delta mutant strain may be twice as infectious as the original strain, Javid said.

What is unclear is whether the disease caused by any of these variants is more severe. John P. Moore, a professor of microbiology and immunology at Weil Cornell Medical College, said:

Why are delta variants so worrisome?

Experts agree that even if the delta variant does not cause a more serious illness (the jury is addressing the issue), its aggressive infection is the most important factor in how the pandemic progresses. To do.

Brooke Nichols, an infectious disease mathematics modeler at Boston University’s School of Public Health, said:

official CDC data Shows that the prevalence of delta variants in the United States has risen from nearly zero in March to over 30% in early June due to prevalence in areas with low vaccination rates.

According to experts, the delta variant will soon become the predominant variant in the United States within a few weeks, even if it does not yet exist, due to its unusually high transmission rate.

“In places like California, delta variants appear to account for about 40% of new cases, contributing to outbreaks in Missouri and Oklahoma,” said Tara Smith, an epidemiologist at Kent State University. Seems to be. “

How much should US vaccinated individuals be concerned about delta mutations?

Studies show that Americans who receive a full course of any of the three vaccines approved by the Food and Drug Administration (Moderna, Pfizer-BioNTech, Johnson & Johnson) are confident in their degree of protection against all four variants, including Delta. Should have ..

William Schaffner, a professor of preventive medicine at Vanderbilt University, said each of the three vaccines “provides very safe protection for people with severe illnesses that require hospitalization.” Stated. “Therefore, you can also prevent entry into the intensive care unit and death.”

But there are important nuances. These vaccines protect vaccinated individuals from serious illnesses caused by variants, but may not protect individuals from mild or asymptomatic infections. In most cases, these infections do not hurt vaccinated individuals, but they can spread the virus to other unvaccinated people.

“Delta variants are more contagious than other variants, and vaccination is slightly less effective in preventing symptomatic infections, but thankfully it is equally effective in preventing serious illnesses.” Said Nichols. “This is a source of concern. Delta continues to circulate among vaccinated individuals and can still cause serious illness in unvaccinated individuals.”

Are there any other interesting variants on the horizon?

The next-generation stocks that are attracting the most attention Lambda variant.. Confirmed in Peru attacked by coronavirus, Spread In at least 27 countries. Early findings suggest that vaccines have high transmission rates and weak efficacy, but more research is needed before these results can be confirmed.

Another variant that is attracting attention is “Delta PlusFirst discovered in Nepal, this variant is a combination of mutations from beta and delta.

“So far, it hasn’t spread,” Havid said of Delta Plus. “But until October or November of last year, I hadn’t heard of any variations of concern, and since the pandemic isn’t over globally, it’s very common to say,’Look at this space.’ is. I think it’s very unlikely that a mutation will completely destroy all vaccine-induced immunity, but that’s not impossible. “