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KPBS Midday Edition

Q&A: What to know about new coronavirus variants

On the eve of the busy Fourth of July holiday weekend, local health officials are raising concerns as the omicron subvariants BA.4 and BA.5, which are now dominant across the country, are taking hold in San Diego. The subvariants are more transmissible and infectious — and becoming more prevalent in the area. According to data released Thursday by San Diego County, there were 2,048 new infections reported in the county on Wednesday and 9,900 in the past week.

Dr. Robert Schooley, an infectious disease expert and professor of medicine with UC San Diego and UC San Diego Health, joined KPBS Midday Edition to answer some questions about COVID-19. The conversation transcribed below has been lightly edited for clarity.

How is San Diego doing right now with COVID-19?


Schooley: As a city, we're doing about as well as the rest of the country. We're still seeing a lot of viral activity in the city. We're not seeing a large number of people in the hospital are dying, although we still see a fair number of people, mainly under- or unvaccinated people or people with underlying conditions are getting these variants, and some of them do get quite ill, but we're seeing a substantial amount of viral activity.

Yesterday, Scripps Health announced that it has seen COVID-19 hospitalizations double and intensive care patients triple over the last month. Is that similar to what other local hospitals are experiencing?

Schooley: Now we're seeing a gradual inching up, and that just is reflected by the extremely large number of cases. When we have as many cases as we do, some people are going to get ill, and we're going to see this rise as long as the caseload rises.

Do we know how prevalent BA.4 and BA.5 are in San Diego right now?

Schooley: Based on the wastewater monitoring that the Search Alliance has been doing, they make up over 50% of the cases we're seeing. It takes a week or so for the data to be analyzed, and, as of a week or so ago, we were already at 50% with a rapid rise, so we're clearly over 50% at this point.


BA.5 in particular has some health officials concerned, including Dr. Eric Topol of the Scripps Research Translational Institute in La Jolla, who calls the BA.5 subvariant "the worst version of the virus that we've seen." What makes BA.5 so unique from previous variants?

Schooley: It's extremely transmissible. It's able to kind of compete with the other variants and push them out of the way at the population level, particularly in populations that have been vaccinated with earlier versions of the virus, the one that circulated initially, and with people who've been infected with earlier versions. BA.5 is different enough immunologically that the level of protection provided by prior infection in vaccines is relatively modest, and people are getting infected despite prior immunization.

Now, having said that, when they do get infected, people who are up-to-date with their vaccinations are much less likely to become severely ill. This decreases the likelihood of being hospitalized or dying many-, manyfold. But people are still getting infected even though they've been heavily vaccinated.

What about breakthrough infections?

Schooley: Well, that's exactly what I'm talking about. The breakthrough infections are people who have been previously infected or who have been vaccinated, and are becoming infected with BA.4 or BA.5 anyway.

I personally am recovering from what I think was likely to be a BA.5 infection. I've been careful throughout the entire pandemic and had not been infected up until this point. A couple of weeks ago, I developed symptoms and tested positive. Based on epidemiology I think it was very likely BA.5.

So this virus is picking off people that have up until now not been infected and who have been really quite careful about vaccination and masking.

Are there any symptoms that are specific to the new subvariants?

Schooley: The main difference that we're seeing is that there's a lot of sore throat. People really have throats that are sometimes as sore as people talk about with infectious mononucleosis, or mono, the teenagers get. There's a fair amount of congestion and nasal stuffiness. We see some of this with earlier variants, but much less than with earlier variants.

You mentioned vaccines. Are we seeing any changes in the number of people getting vaccinated today?

Schooley: Well, we're seeing a slowdown in boosting. The boosters, even with the original viral variants, do provide a fair amount of protection for severe disease. And so we have a large number of people in the population who got their initial vaccinations now, some of them over a year ago, particularly people who are older, because we vaccinated them first. And, if they've not been boosted, their level of protection with a difference between BA.5 and prior variants and with the time that has passed, their level of protection is really quite sketchy.

Have health officials changed mask guidance even as a result of these new variants?

Schooley: Mask mandates haven't changed. However, what has happened is we're increasingly trying to encourage people to use their judgment and their knowledge about level of viral activity around them to make their own decisions.

I, for example, know that there's a lot of virus here in San Diego, and so, when the levels of viral activity are that high, what I will do is put on a mask when I go into a place indoors where there's going to be a lot of people. I don't wear a mask everywhere I go. There are areas that are outdoors or only people that I'm normally around, family and close friends.

But it is the kind of environment in which it makes sense for people to add that one more level of protection when risks are high. That is larger numbers of people that you don't interact with indoors.

And we have heard about the potential for newer coronavirus boosters being available this fall to specifically target omicron. What's the status there?

Schooley: They're under really very active investigation. They look to be just as well-tolerated as the current vaccines. Arms are sore for a short while, but they develop higher levels of immunity against the circulating omicron variants. Now, there are some nuances here because the vaccines that have been worked on most recently are directed at the omicron variants that we were seeing in San Diego in December and January, not BA.4 and BA.5. Those are just getting started now.

And so what we really have here is a moving target, very much like we do with flu every year. And we're going to have to struggle to keep up with this moving target, with updating the vaccines.