BA.5 most contagious strain yet, second booster on the way

It’s being called the worst version of COVID to date by some doctors — and now the BA.5 subvariant of omicron is becoming the dominant strain in the U.S. after sweeping across Europe, Africa, and Australia.

The power of BA.5 is its capacity to spread. It is even more transmissible than omicron subvariant BA.2, which spread during the spring, and the original omicron variant responsible for the winter wave; each of those strains were, in their heyday, more contagious than what had been seen before.

It also does a better job of evading prior immunity.

“It’s how contagious it actually appears to be, and the fact that our antibodies that we have created from getting immunized or from previous infections don’t seem to be standing up to it very well,” said Mercer Island-based Dr. Gordon Cohen on KIRO Newsradio’s Seattle’s Morning News.

BA.5 reinfects former COVID patients as health officials push for updated vaccine

Dr. Deborah Fuller at UW Medicine explained that the R-naught of BA.5 — the number of people each person with the illness infects — is high.

“It’s definitely much higher than what we’ve seen in any other COVID-19 variant before, and the previous variants were around seven to eight — meaning that if you go into a room, a person infected could infect seven to eight people,” Fuller said.

She said it might even turn out to be almost as contagious as measles, which has an R-naught in the teens.

“It’s quite possible, once they’ve done some more epidemiological analyses, that we might see that BA.5 is getting closer to measles,” Fuller said. “And that is a concern.”

While each new variant does appear to be less and less severe in its symptoms, Cohen said you should still do everything you can to try not to catch it. Each time you catch the illness, you become susceptible to long-term, lingering effects.

“Getting infection still runs the risk of developing long-term symptoms, long COVID, which we don’t really understand very well,” he said.

The good news is, boosters coming out this fall will combat BA.5 and its predecessor BA.4 specifically. But what do we do in the months in between, as BA.5 takes hold?

First on the agenda should be getting a second booster, Fuller said. Those 50 and older, or those 12 and older with compromised immune systems, qualify for a second booster.

“If you’re eligible, definitely go out and get that booster immunization for sure … even as new, updated boosters are going to get rolled out in the fall, don’t hesitate to take what’s offered to you right now,” Fuller said.

If you get a booster now, it will still be perfectly fine to get another one in the autumn, as the BA.5-targeted shots come out.

“As long as they’re spaced at least a month apart, your body is going to be able to respond very well to any additional booster dose,” Fuller said.

While the current vaccines and boosters were developed before BA.5 reared its head, they will still help you build up an immune response that will make you less likely to catch the new variant, and certainly far less likely to develop serious symptoms.

“The virus is able to escape to some degree from antibody responses. But some of the antibodies that are generated as a result of your booster immunization are still able to interact and bind up with the virus,” Fuller explained. “When you have higher amounts of that, you increase the chances of preventing that infection.”

But what about the young adults who do not fall into the eligibility category for booster number two?

“Our best solution, if you’re not eligible for getting vaccinated, is to just put that mask on when you’re going in crowded areas,” Fuller said.

In fact, she would like the government to re-instate some type of masking requirement, at least in crowded situations.

However, you can take comfort in knowing that even if you are many months past your last shot, you are still much better protected against the virus — including its more contagious new forms — than you were two years ago, before the availability of vaccines.

“Even after six months, you still have a significant level of immunity in your body. You’re still much, much better off than we were before we had any other immunity,” Fuller said. “So the body is still able to recall those immune responses, still able to accelerate clearance of the virus from our body, and help us to recover much more quickly.”

And as a society, she added, with the prevalence of vaccines, at-home tests, contact tracing, COVID treatments, and sheer knowledge about the virus, we are much better equipped than we were in summer 2020.

Additionally, Fuller said that the young adults who are ineligible for second boosters at the moment should get their chance this fall when the BA.5-targeted boosters come out — the CDC is expected to expand eligibility.

While BA.5 is alarming in how easily it spreads, Fuller said we should not resign ourselves to getting it.

“I don’t think that we should give up hope,” Fuller said. “I think there’s still a lot of good reason to believe that we can manage and control this and be able to reduce our chances of getting infected with it.”

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