Lisa Maragakis, M.D., M.P.H., senior director of infection prevention; Stuart Ray, M.D., vice chair of medicine for data integrity and analytics; and Robert Bollinger, M.D., M.P.H.; the Raj and Kamla Gupta Professors of Infectious Diseases at Johns Hopkins Medicine 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 a variant of concern?
Coronavirus variants are classified into different categories by organisations such as the World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC).
A variant of interest is a coronavirus variant that, compared with earlier forms of the virus, has genetic characteristics that predict greater transmissibility, evasion of immunity or diagnostic testing, or more severe disease.
A variant of concern has been observed to be more infectious and is more likely to cause breakthrough infections or reinfections in those who are vaccinated or previously infected. These variants are more likely to cause severe disease, evade diagnostic tests, or resist antiviral treatment. Alpha, beta, gamma, delta, and Omicron variants of the SARS-CoV-2 coronavirus are classified as variants of concern.
A variant of high consequence is a variant for which current vaccines do not offer protection. As of now, there are no SARS-CoV-2 variants of high consequence.
Can the new variations be protected against using COVID-19 vaccinations and boosters?
According to Ray, "laboratory investigations have shown that some immune reactions induced by the existing vaccinations may be less effective against some of these variations." Those who are eligible for COVID-19 boosters should get them to increase their defenses against infection and serious illness.
"A decrease in one immune response component does not imply that the vaccinations will not provide protection." The immune response contains several components, including B cells that produce antibodies and T cells that can react to infected cells.
"People who have received the vaccines should watch for changes in guidance from the CDC and continue with coronavirus safety precautions to reduce the risk of infection, such as mask-wearing, physical distancing, and hand hygiene."
"We deal with mutations every year for the flu virus and will keep an eye on this coronavirus and track it," says Bollinger. "If there were ever a major mutation, the vaccine development process can accommodate changes if necessary," he explains.
The Omicron Variant
In November 2021, a variant of the SARS-CoV-2 coronavirus emerged and was named Omicron by the WHO, which lists it as a variant of concern. Cases of the highly contagious variant, including a subvariant called BA.2, or "stealth omicron," have caused COVID-19 surges, particularly in areas where safety precautions have been relaxed.
"The Omicron variant is responsible for the largest surge since 2019," says Maragakis.
"Omicron has numerous mutations that all appeared at once." It’s very different from previous versions, including Delta. It has over 50 mutations, many in the spike protein, which is how it gets into our cells in the first place. The spike protein is also one of the most prominent exterior features of the virus that our immune system recognizes, responds to, and uses to develop antibodies.
"Unfortunately, omicron is a perfect storm: mutations gave it the ability to escape weak immune responses AND become more transmissible from person to person.
"Omicron has numerous mutations that all appeared at once." It’s very different from previous versions, including Delta. It has over 50 mutations, many in the spike protein, which is how it gets into our cells in the first place.
The spike protein is also one of the most prominent exterior features of the virus that our immune system recognizes, responds to, and uses to develop antibodies.
"Unfortunately, omicron is a perfect storm: mutations gave it the ability to escape weak immune responses AND become more transmissible from person to person.
Omicron and BA.2: Do they cause more severe illnesses?
Bollinger says, "The answer appears to be no." "In fact, there is evidence that omicron may cause less severe disease than the delta variant."
"What we see is that omicron may have more of an affinity for our upper airways than our lower airways and can be more easily spread through talking, coughing, or breathing, especially from people without masks on." "Omicron also may have more potential for airborne aerosolization of the virus, hanging in the air in indoor settings," Maragakis says.
Are omicron and BA.2 more contagious than other variants of the coronavirus?
Omicron and especially its subvariant, BA.2, are very contagious, more so than the original coronavirus or the delta variant.
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