Medical experts say the most dominant form of COVID-19 that is currently spreading in the United States appears to be spreading faster than earlier variants or versions. Plus it might be better for escaping immunity and could cause more serious illnesses.
Scientists say the “sub-variant” currently spreading is a mutation genetically linked to the Omicron and Delta versions of COVID-19. These two versions were dominant in the United States in the past. The new viral form has a genetic quality that comes from the past of the pandemic. This is called a “delta mutation”.
Dr. Wesley Long is an infectious disease expert at Houston Methodist in Texas. He said it appears to allow the virus “to escape the pre-existing immunity of vaccination and prior infection, especially if you have been infected with the Omicron wave. The mutation is believed to be able to better evade immunity as the older Omicron variant did not have it.
The current variant spreading in the United States, known as BA.2.12.1, was responsible for about 58% of COVID-19 infections in the United States a week ago.
There are other types of Omicron virus that carry the mutation. Two in South Africa, known as BA.4 and BA.5, have the same genetic mutation as delta. And BA.2.12.1 has one that is almost the same.
This genetic change may confuse people who caught the first version of Omicron and thought it made them unlikely to get COVID-19 again soon. Most people don’t know for sure which type of coronavirus caused their illness. But the first version of Omicron caused a huge wave of cases late last year and early this year.
Long says lab data suggests that prior infection with the first Omicron is not very protective against reinfection with the new mutations. However, a study by researchers at Ohio State University found that those with Delta may have some immunity to new viruses.
Dr Shan-Lu Liu co-authored the study. He said the degree of protection provided by a Delta infection depends in part on how long a person has been sick. This is because immunity wanes over time.
Long advises people who have become ill with Delta not to consider themselves completely protected against the new subvariants, especially if they are not vaccinated. He said, “I wouldn’t say anyone is safe.
Liu said booster shots can provide strong protection against new types of COVID-19. In general, vaccines and past infections can protect people from the worst consequences of COVID-19. But Liu added that early data points to more severe disease with the New Mutants. Scientists say it’s too early to know if the releases will lead to a higher rate of hospitalizations and deaths.
Although home testing makes it difficult to track all COVID cases in the United States, data from Johns Hopkins University shows they average nearly 107,000 a day. That’s up from 87,000 two weeks ago. And the Centers for Disease Control and Prevention (CDC) has found that the number of people entering hospitals with COVID-19 has been increasing since around mid-April.
Long said, “Hopefully we don’t see a similar increase in hospitalizations that we’ve had in previous waves.” He added: “But with COVID, anytime you have a lot of infected people, it’s just a numbers game. Some of these people are going to be tough. Some of these people will have to be hospitalized. Some of them, Sadlyare going die.”
I am Gregory Stachel.
The Associated Press reported this story. Greg Stachel adapted the story for Learn English.
words in this story
dominant – adj. the main or most important
immunity – nm to be protected against disease
mutate – v. to change (a gene) and create an unusual characteristic in a plant or animal
prior – adj. existing earlier in time
wakeup call – nm an extra amount of a substance (called a vaccine) that is injected with a needle into a person or animal to help protect against a particular disease
Sadly – adv. used to say something bad or unlucky has happened
die – v. die
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