'People should be worried' about coronavirus variants, expert says

Thanks to natural mutations, more-infectious and potentially deadlier variants of the virus that causes COVID-19 are now racing around the globe and are threatening to turn back the recent progress against the disease due to vaccination.

Last week Houston became the first big American city to report the presence of all five variants that have medical experts worried — a California strain called B.1.427/B.1.429, a New York variant classified as B.1.526, the Brazilian P.1 strain, a strain called B.1.351 that is believed to have originated in South Africa, and the U.K. mutation B.1.1.7, which the Centers for Disease Control and Prevention predicts will become the dominant strain in the U.S. by the end of the month.

Each new variant comes with new, worrisome features. P.1, for instance, has been found to make reinfection easier, while new studies show that B.1.1.7 extends the infectious period beyond the original strain.

With so many questions being raised by the growing number of mutations, Yahoo News turned to resident medical expert Dr. Kavita Patel for answers. (The following interview was edited for clarity.)

Yahoo News: How worried should Americans be about coronavirus variants now circulating?

Dr. Kavita Patel: I think people should be worried. There’s a large number, a majority of the population that has not been vaccinated. They should be very worried, because they are prime targets for these viruses with the variants to reproduce.

Remember, the goal of a virus is not to kill people, it’s actually just to continue to stay alive, and the only way it does that is by infecting people. People who are not vaccinated should be incredibly worried, which is why I, in turn, am very worried about the variants as I watch now 12 states and counting, very big states including Texas and Florida, lifting any sort of mask requirements or leaving it to individuals or businesses. That’s a group that should be very worried.

Even people who are vaccinated should have some concern because all these [vaccine] trials that went on, the majority of them did not happen when we had experience with these variants. So, we are all happy that the vaccines work to some degree against the variants, but we’re not quite sure how long it will last, whether we need a booster. All the manufacturers are already talking about booster vaccines, so getting a vaccine, like I did, is a ton of relief mentally, but, I’ll be honest with you, I’m still worried when I leave my house, mostly because of these variants.

To date, a little over 16 percent of the U.S. population has received at least one dose of a COVID-19 vaccine. Is there a level at which mutations won’t pose as big of a threat?

We do know that in just kind of normal virology or infectious disease that over 50 percent and higher, the more people who are vaccinated, [the more] decreased the rate of infectivity becomes. The R naught or the Rt, which is [the measure of] how many people, if you get the infection, you will infect, that number is already coming down and will continue to go down. It won’t get to zero, but it will be pretty darn close. So that if you get infected there’s basically no chance of you infecting anyone else when we get to a certain level of immunity.

Everybody’s asking, ‘Is that herd immunity?’ But it’s not a light switch, so above 50 percent, the higher we go, the more the chances of getting infected decrease. That’s good news. We’re getting closer and closer, but we’re not going to get there in the next — it’s going to be weeks if not months before we get to that point.

One fear among epidemiologists is that the virus may undergo a mutation that will render existing vaccines useless. If that happens, are we starting from scratch?

It’s hard to render them totally useless. It would have to be such a radical alteration. Remember, the vaccines themselves don’t just target one type of element on the spike protein or re-create the spike protein in one way. The vaccine delivers what we call a polyclonal antibody response. What that means is that the vaccines ­— all three, in fact all the ones that are available around the world — all of them provoke an immune response to very different parts of that spike protein.

When Pfizer said that their vaccine develops antibodies against the variants but just at a lesser degree, what that really means is that it works against the variants, but it’s because the response that it’s developing is only so good. It’s not 100 percent, not 95 percent, but it’s probably about 80 percent — and that’s a number I’m making up. … What it [variants] could do — what’s more likely — for someone who is vaccinated, we are very confident that person won’t die or get severe disease, but it’s highly likely that some of these variants could cause some vaccinated people to get severe disease.

The common flu mutates each year, requiring a new vaccine. Is this what we can expect with COVID-19, a new yearly vaccine?

We’re definitely headed to some sort of seasonal vaccine; whether it’s every year, twice a year, once every two years, the timing is not certain.

Is it possible that the virus could mutate so fast that it could require more than one vaccine per year?

The short answer is: Possibly. We know that everyone is working on a booster. We’re used to boosters in vaccine terminology. We use a booster in shingles, we use boosters in tetanus. We use boosters in many other vaccine settings, so it’s not unusual to see a booster. What would be interesting is if we need a booster every six months after we got vaccinated — not because immunity goes away after six months, but in dealing with the variants, having so many mutations accumulate.

One of the reasons I’m not as worried as some who are talking about a fourth surge and it being catastrophic is that this is a virus that has not mutated a ton. If you step back and look at how many people have been infected, we’re only now, in the later months, talking about these really threatening mutations, which means we’ve gone a year-plus without having wave after wave of mutations and variants.

That’s why we think that the B.1.1.7 variant, those series of mutations, will be the dominant strain in the United States by the end of this month and then it will likely take a while before we see some other strain or variant that could overtake that. If you think about that, it means the timing could be yearly for a vaccine booster or a different vaccine altogether.

But it strikes me that the virus is doing a great job of mutating. Even in the time it took for the virus to spread from China to Europe to the U.S., by the time it arrived in New York, wasn’t that already a different strain?

We’re using very different terms. The virus has mutated a ton. A variant doesn’t become a strain until it’s clinically concerning. It [the virus] has mutated from the get-go, that’s correct. But it hasn’t mutated in a way that has caused such a significant clinical impact until recently, and that’s the difference. So we have a Europe strain, we have a Wuhan strain, but the clinical appearance of the virus never really changed, and the difference now, and the reason we think B.1.1.7, B.1.351, P.1 are causing more concern [is] because they are more transmissible and potentially more deadly. But look at how long it took.