Omicron subvalants BA.4, BA.5 and the future of coronavirus

As we move to another location with COVID-19, the landscape of coronavirus variants changes once again.

The relatively new omicron subvariant – BA.2.12.1 – now accounts for the majority of COVID-19 cases in the country. But experts say two more options, BA.4 and BA.5, could take off very well in the next few months, taking the steam.

As of June 18, sub-variant BA.2.12.1 was responsible for approximately 56% of all COVID-19 cases in the United States, according to the latest data from the Centers for Disease Control and Prevention.

At the same time, BA.2, which previously dominated, now accounts for only 9% of cases. In early May, BA.2 and BA.2.12.1 were responsible for nearly half of all coronavirus infections in the United States, CDC data showed. And in March, BA.1 (the original omicron strain) was still in the lead.

In some parts of the country, BA.2.12.1 occupied even more: “I’m in Connecticut, and that’s like 80% of all sequences we see now,” said Anne Khan, Ph.D., post-doctoral student. This was announced today by a researcher at the Yale School of Public Health.

“And the exchange between BA.1, then BA.2 and now BA.2.12.1 was so fast, it’s unexpected,” Khan said, adding that his work is investigating the evolution of the SARS-CoV-2 virus. “We’re in BA.5 right now and it’s June 2022. It’s the first of the whole family to be born in November 2021. So it’s really interesting.”

This rapid exchange of variants is thought to be due to mutations in the spike protein, which allow each strain, especially the virus, to evade immune protection. In the case of BA.2.12.1, “it is believed that this will help to rule out some antibodies caused by previous infections or vaccines,” said Bill Hanaj, Ph.D., associate professor of epidemiology at Harvard TH Chan School, the Ministry of Public Health said today .

However, it is unclear to what extent the success of BA.2.12.1 “depends on the nature of the transmission,” said Hanaj, co-director of the Harvard Center for Infectious Diseases.

Does BA.2.12.1 lead to more severe disease? “Some parts of the country have been hit hard compared to BA.2.12.1 and this has not really resulted in a very large number of hospitalizations or deaths,” Hanaj said.

However, because of this subvariant, it is difficult to estimate the true severity of the disease. “The vast majority of the population has been vaccinated or has had COVID infection before and this affects the severity of the disease because they have some basic immunity,” the doctor said. Anna Durbin, an associate professor at Johns Hopkins University School of Medicine, said today.

“The good news we can get from this is that we are still seeing the protective effects of the vaccine against severe forms of the disease,” Durbin said, noting that his research focuses on protective diseases when evaluating vaccines against infectious diseases.

On the horizon: BA.4 and BA.5

While BA.2.12.1 is now predominant in the United States, other emerging omicron sub-variants called BA.4 and BA.5 have begun to gain momentum. First identified in South Africa, BA.4 now accounts for 11% of cases in the U.S., and BA.5 is responsible for almost 24%, CDC data show.

“They’re not flying at the same pace everywhere,” Hanaj said, noting that two new strains appear to be emerging in Texas and Florida, and that BA.5 cases are also on the rise in Washington state.

“In general, it’s unclear whether there’s a reason for this, they’re flying faster in places where BA.2 isn’t seen much,” he explained. This could be because the BA.2 specifically offers some degree of protection against these new options, or simply because a new infection – in any case – provides some coverage, he said.

Khan said he expects the new options to be “accepted by the end of the summer” and noted that Portugal is now seeing significant growth due to the BA.5 cases. This is “extremely dangerous because it is one of the most vaccinated populations in the world, especially when it comes to amplifiers,” he said.

The companies are working on the next generation of COVID-19 amplifiers, which will focus on specific options related to omiron. For example, Modernna plans to release a bivalent vaccine this fall that targets the original strain of the coronavirus, as well as the omicron variant.

The company shared new clinical trial data in a press release this week, in which the shot provides better protection against BA.4 and BA.5 than the original vaccine. Buster was more effective against the original omicron strain.

What options can we see in the future?

Almost all experts agreed that new options were provided. And given that all of the last few dominant options were in the omicron family, this is a good bet, but not a guarantee – the latter will be too.

“You never want to be surprised by this thing, but it seems to have changed,” Hanaj said. And now experts don’t expect another new option to emerge out of nowhere and dominate as fast as the omicron, Khan said.

Previous variants, including alpha, delta, omicron (BA.1) and BA.2, “all began to develop in the first few months after the virus entered the human population. They did not originate from each other,” Hanaj explained. “But what we’re seeing now is taken from the omicron, it’s something new.”

At the same time, it is important to recognize that these omicron subvariants are not similar to each other: “We call it the omicron family, but in fact if you look at the genetic distance of the members of this family, they are different for each other. was the alpha delta, ”Khan said.

Eventually, the options will “come; they won’t stop,” Durbin said. “What do we know about other seasonal coronaviruses? They keep coming back, they continue to mutate, and we continue to be infected.”

The key questions for researchers are whether the virus causes more severe disease, whether we should continue to take boosters to protect ourselves, and whether those vaccines need to be constantly updated to better adapt to the circulating strains. , he said. Both Moderna and Pfizer are working on boosters that target the omicron version expected in the fall.

How to protect yourself and your community

“We can never completely eradicate all variants of the coronavirus,” Hanaj said. But there are things we can do to reduce the likelihood of more occurrences and reduce their chances of being occupied.

  • Wear a mask. Yes, face masks still work – especially high quality respirators such as KN95, KF94 and N95. Wearing masks is especially useful in dangerous situations, such as crowded indoor events. “If it’s a good mask, it will protect you no matter what people around you are doing,” Hanaj said.
  • If you are fit, make a plan to get your second strength. “We’re looking at up to a month or two,” he said, noting that the main protection from binoculars is less time consuming. need to. But if you want extra protection before a trip or event, it’s a good idea to plan ahead.
  • Check with your local health department. Because COVID-19 is distributed differently in different parts of the country, it is useful to keep an eye on the situation around you. There are some on the CDC website, Durbin said, but it usually directs people to the local health department’s website for the latest information about their community.
  • If you get sick and can stay home, you should. Even if you test negatively at home with a quick COVID-19 test, don’t think you’re accurate. “If you can spend a sick day, you shouldn’t go into an office where you’re sneezing, coughing or having a fever,” Durbin said. Preventing the virus from spreading to others and “reducing the overall burden is our best bet against emerging options,” Khan agreed.
  • According to Durbin, vaccinating young children will help protect them and reduce the number of infected people. This transmission may also affect the emergence of new options.
  • Wait for the next generation of lifts. According to experts, the next crop of vaccines will be an important step forward, focusing on specific options or multiple options. “Current vaccines have been developed against strains of two or more years of age,” Durbin said. “We know the virus is widely mutated.”

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