A new omicron subvariant of the virus that causes COVID-19, BA.2, is quickly becoming the predominant source of infections amid rising cases around the world. Immunologists Prakash Nagarkatti and Mitzi Nagarkatti of the University of South Carolina explain what makes it different from previous variants, whether there will be another surge in the U.S. and how best to protect yourself.
The first omicron subvariant, BA.1, is unique in the number of alterations it has compared to the original version of the virus — it has over 30 mutations in the spike protein that helps it enter cells. Spike protein mutations are of high concern to scientists and public health officials because they affect how infectious a particular variant is and whether it is able to escape the protective antibodies that the body produces after vaccination or a prior COVID-19 infection.
Does Previous Infection With BA.1 Provide Protection Against BA.2?
Yes! A recent study suggested that people previously infected with the original BA.1 subvariant have robust protection against BA.2.
Because BA.1 caused widespread infections across the world, it is likely that a significant percentage of the population has protective immunity against BA.2. This is why some scientists predict that BA.2 will be less likely to cause another major wave.
However, while the natural immunity gained after COVID-19 infection may provide strong protection against reinfection from earlier variants, it weakens against omicron.
How Effective Are Vaccines Against BA.2?
A recent preliminary study that has not yet been peer reviewed of over 1 million individuals in Qatar suggests that two doses of either the Pfizer — BioNTech or Moderna COVID-19 vaccines protect against symptomatic infection from BA.1 and BA.2 for several months before waning to around 10 percent. A booster shot, however, was able to elevate protection again close to original levels.
Importantly, both vaccines were 70 percent to 80 percent effective at preventing hospitalization or death, and this effectiveness increased to over 90 percent after a booster dose.
How Worried Does the U.S. Need to be About BA.2?
The rise in BA.2 in certain parts of the world is most likely due to a combination of its higher transmissibility, people's waning immunity and relaxation of COVID-19 restrictions.
Though there may be an uptick of BA.2 infections in the coming months, protective immunity from vaccination or previous infection provides defense against severe disease. This may make it less likely that BA.2 will cause a significant increase in hospitalization and deaths. The U.S., however, lags behind other countries when it comes to vaccination, and falls even further behind on boosters.
Whether there will be another devastating surge depends on how many people are vaccinated or have been previously infected with BA.1. It's safer to generate immunity from a vaccine, however, than from getting an infection. Getting vaccinated and boosted and taking precautions like wearing an N95 mask and social distancing are the best ways to protect yourself from BA.2 and other variants.
This article is republished from The Conversation under a Creative Commons license. You can find the original article here.
Prakash Nagarkatti is a professor of pathology, microbiology and immunology at the University of South Carolina. He receives funding from the National Institutes of Health and the National Science Foundation. Mitzi Nagarkatti also is a professor of pathology, microbiology and immunology at the University of South Carolina. She also receives funding from the National Institutes of Health.
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