4 virus variants are spreading in the US, and studies suggest they can make people sicker, evade the immune response, or spread faster. Here’s why experts are concerned.
- There are four coronavirus variants that experts in the US are worried about.
- These include variants first identified in South Africa, the UK, and Brazil.
- They may spread more easily, make people sicker, escape immune responses, evade tests, or render treatments ineffective, studies suggest.
- See more stories on Insider’s business page.
Several coronavirus variants have evolved mutations that mean they spread more easily, make people sicker, escape immune responses, evade tests, or render treatments ineffective.
These are called “variants of concern” by the Centers for Disease Control and Prevention (CDC), and there are four in the US. They differ from the original virus strain in a number of key ways.
B.1.1.7, first found in the UK
B.1.1.7 was first detected in two people in south-east England. It was reported to the World Health Organization (WHO) on December 14.– ADVERTISEMENT -https://s.yimg.com/rq/darla/4-6-0/html/r-sf-flx.html
It has been identified in 111 countries worldwide, including the US, where there are more than 20,000 reported cases, according to the CDC. Michigan has the highest proportion of B.1.1.7 cases of any state, at over 57%.
B.1.1.7 is between 30% to 50% better at spreading from person to person than other coronavirus variants, according to UK scientists.
B.1.1.7 could be more deadly. The UK government’s New and Emerging Respiratory Virus Threats Advisory Group (NERVTAG) reported a model on January 21 that showed someone infected with B.1.1.7 is 30% to 40% more likely to die than someone with a different variant.
Community-based studies in England, Scotland and Denmark showed that infection with B.1.1.7 in the community causes a higher risk severe disease requiring hospital treatment and death.
But there is a lot of uncertainty around the numbers. And two studies published in the Lancet Infectious Diseases and the Lancet Public Health on April 13 indicated that B.1.1.7 was more infectious, but didn’t cause worse illness in hospitalized patients.
B.1.351, first identified in South Africa
B.1.351 is thought to be 50% more contagious than the original strain, according to South African health officials.
It’s not thought to be more deadly. But there is evidence from South Africa that when hospitals came under pressure because of the variant’s spread, the risk of death increased.
The variant may evade the body’s immune response, data suggests. Antibodies work best when they attach snugly to the virus and stop it from entering our cells. The B.1.351 variant has mutations called E484K and K417T at the site where antibodies latch on. In early lab tests, antibodies produced by Pfizer and Moderna’s COVID-19 vaccines couldn’t attach as well to B.1.351, compared to the original coronavirus.
We don’t know yet whether this impacts the vaccines’ effectiveness in real-life. A real-world study from Israel published on April 10 suggested that Pfizer’s vaccine provided less protection against B.1.351 than the original coronavirus. But it was focused on those who have already tested positive for the virus, not total infection rates, so we can’t draw firm conclusions. Pfizer has published some data suggesting its vaccine may help protect people against this variant.
Johnson & Johnson’s COVID-19 vaccine was 64% effective at preventing COVID-19 in trials in South Africa, where 95% infections are caused by B.1.351, and 72% effective in the US, where B.1.351 accounts for less than 1% of sequenced coronavirus tests.
AstraZeneca’s COVID-19 vaccine didn’t prevent mild to moderate disease caused by B.1.351 in a trial, and we don’t yet know if AstraZeneca’s shot still protects against severe illness caused by the variant.
It is unlikely that vaccines will become completely useless against the variant. Existing vaccines could be updated and tailored to a new variant within weeks or months, or you may require a booster shot.
P.1, first identified in Brazil
The variant found in Brazil was first detected in four people in Japan, who had traveled from Brazil on January 2. It was identified by the National Institute of Infectious Diseases on January 6, and reported to the WHO that weekend.
P.1 is twice as contagious as the original coronavirus – it was initially detected in Amazonas, north-west Brazil, on December 4, and by January 21, 91% of people with COVID-19 in the region were infected with P.1, according to the WHO.
P.1 has similar E484K and K417 mutations as B.1.351, which means it can also evade antibody responses.
This could be the reason P.1 is able to reinfect people who have already caught coronavirus – a study published April 14 showed that previous coronavirus infection only offered between 54% and 79% of the protection for P.1 than for other virus strains.
P.1’s mutations could also mean that vaccines work less well.
COVID-19 vaccines from Pfizer and AstraZeneca work against P.1. Moderna’s hasn’t been tested. Johnson & Johnson’s COVID-19 vaccine was 68% effective in trials in Brazil, where the variant is the most common strain, compared with its 72% efficacy in the US, where P.1 accounts for 0.1% of sequenced coronavirus tests.
B.1.427/B.1.429, first identified in California
The variant first found in California consists of two slightly different mutated forms of the virus, called B.1.427 and B.1.429. It is also called CAL.20C, using another naming system. It was first found in California in July and has now been detected across the US and elsewhere, including in Australia, Denmark, Mexico, and Taiwan, according to the Global Initiative on Sharing Avian Influenza Data (GISAID).
B.1.426/B1.429 are estimated to be 20% more infectious than the original coronavirus – they have become the most common coronavirus variants in California, accounting for more than 53% of sequenced cases, according to the CDC. This is likely because of a mutation called L452R mutation, which in early lab studies was shown to help the virus infect cells.
COVID-19 vaccines haven’t yet been tested against this variant specifically. But early lab studies showed that antibodies produced by previous COVID-19 infections worked only half as well against the variant as they did with the original coronavirus strain.
Variants of interest
So-called “variants of interest” have potentially worrisome mutations, but how they affect the virus’ behavior is not yet known..
B.1.526/ B.1.525, first identified in New York
These two variants were detected in New York in late 2020. They are “variants of interest” because they have mutations that could evade antibody responses. B.1.525 accounts for 0.5% of sequenced coronavirus tests in the US, according to the CDC.
P.2, first identified in Brazil
P.2 was first detected in Brazil in April 2020. It’s a “variant of interest” because it has mutations that could mean it evades antibody responses. Less than 1% of sequenced coronavirus tests in the US are P.2, according to the CDC.
B.1.617, first identified in India
B.1.617 was first found in India on March 24, but dates back to in October 2020, according to GISAID. It is not yet a “variant of interest”, according to the CDC. But the UK has designated it a “variant under investigation” because it has some potentially worrying mutations: it has the same L452R mutation as the variant first found in California, B.1.426/B1.429, as well as a mutation called E484Q that is similar to the E484K mutation found in the variants first found in Brazil, P.1, and South Africa, B.1.351.
No studies yet have found that this so-called “double mutant” is deadlier than earlier versions of the virus, or that it can evade vaccines.
Human behavior can help stop them spreading
The WHO has said that everyone should double down on precautions that stop the spread of variants, such as social distancing, hand-washing, mask wearing, and avoiding crowds.
“Human behavior has a very large effect on transmission – probably much larger than any biological differences in SARS-CoV-2 variants,” Paul Bieniasz, a virologist at the Howard Hughes Medical Institute, told Insider.
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