When omicron wave hit the United States, it spread across the country like a steppe fire.
Various models estimate that anywhere from 50% to 75% of Americans had become infected with the variant by the end of the increase.
So what does this mean for the rest of the American population who did not get COVID-19 during the last wave?
Because omicron has shown the ability to cause breakthrough infections despite vaccination status, this has led to fears that everyone will catch the virus at some point. However, it is important to clarify that COVID vaccines remain extremely effective in their primary purpose of preventing hospitalization and death.
However, public health experts said that it is not inevitable that Americans who have not yet received COVID will eventually, and that there are several reasons why people have been able to avoid infection so far, including certain types of behavior. , such as being serious about masking and social distancing, vaccination rates and maybe even genetics.
Why some people have not received COVID yet
Doctors said there are several reasons why millions of Americans have not yet contracted the virus.
One of these reasons is human behavior, which means that people take appropriate precautions to reduce their risk of becoming infected.
“Sometimes people do not get infected because they are extremely careful,” said Dr. Mark Siedner, an associate professor of medicine at Harvard Medical School, to ABC News. “There are people who have their own health behaviors or are concerned about their own health or the health of their loved ones.”
He continued: “Maybe they have comorbidities… they may be the kind of people who are largely homebound, or who do not really interact with others or are particularly careful about things like social distancing and masking, and that can certainly stop a majority of infections or certainly reduce the risk where you are unlikely to be infected. “
These people are also more likely to have been vaccinated and boosted, and experts said it is impossible to ignore the effect vaccination rates have had on preventing infections among Americans.
Dr. Jonathan Grein said there are also social and environmental reasons that can determine why some Americans have been infected and others have not been infected, including how much time people spend with others and where they interact.
“Some people may come in more contact with people more regularly than others,” Grein, director of hospital epidemiology at Cedars-Sinai in Los Angeles, told ABC News. “There are probably also environmental reasons, the virus is likely to be transmitted more efficiently under certain circumstances like classic indoor, poorly ventilated space compared to outdoors.”
But genetics can also play a role.
Dr. Stuart Ray, a professor of medicine at Johns Hopkins University, said similar circumstances have been seen in people who were at high risk for HIV but who did not get the disease.
“One of the things that was discovered was people who had mutations in [a certain] receptor… and it was associated with not getting infected with HIV and in the uncommon people who become infected, very slow progression to AIDS, “he told ABC News.
Although there has not yet been a clearly identified gene, Ray said it is possible that some people are genetically less susceptible to COVID.
Is COVID-19 infection inevitable?
Experts said they do not believe that infection with COVID-19 is inevitable or at least inevitable for everyone.
“The fact that we are now two years in, and a significant number of people have not yet been infected, is good proof that it is not inevitable that everyone will get it,” Grein said. “One thing we have clearly identified is that being vaccinated is the most important variable in deciding how protected someone can be.
Ray said, however, that he believes Americans who are unvaccinated but who have not yet contracted the virus will eventually.
“As these variants have become more and more contagious, the likelihood of these people becoming infected seems significant,” he said. “I think it’s likely that people who have not been vaccinated and have not had COVID will eventually get it because we are not going to track infections as closely as we have done in the past, and so there will be less attention as viruses hire communities … and at some point their bubble will burst if they are not immune. “
Dr. Peter Chin-Hong, a specialist in infectious diseases at the University of California, San Francisco, said the COVID situation in Hong Kong is a “horror story” about what can happen in an unvaccinated country.
Hong Kong currently has the world’s highest COVID-19 death rate with a seven-day rolling average of 37.68 per million people, according to Our World in Data.
“A lot of people were vaccinated in Hong Kong, but that was the reverse of the United States,” he said. “In the US, so many seniors are vaccinated and boosted, but in Hong Kong it was the opposite. Very few seniors were vaccinated, so when they got it, even something ‘milder’ like omicron, there were still a lot of people who died, so it is a cautionary tale. “
There is no figure that determines when the United States has sufficient immunity
Early in the pandemic, Dr. Anthony Fauci and other public health experts said the United States had to vaccinate 75% to 85% to obtain herd immunity.
Currently, only 65.3% of all Americans are fully vaccinated.
When British Prime Minister Boris Johnson announced last month that he would drop the remaining COVID-19 restrictions in the UK, supporters said one of the reasons was that government figures showed that more than 98% of the adult population in England has traceable COVID-19 antibodies either from previous infection or from vaccination.
But officials said there is no number in the United States that officials can declare there is “enough immunity for.”
“The game has changed to some degree because the virus has been able to infect so many people and evolve,” Ray said. “It’s the level of infectivity right now is so high that the level of antibodies required to prevent infection, the level we have to achieve is difficult to maintain for a long period of time.”