Ask an epidemiologist: Who should get the new COVID vaccine?

CATHY WURZER: The latest COVID 19 vaccines are on the way to your local pharmacy and doctor's office. They were approved by the Federal Food and Drug Administration last Thursday. Health officials are recommending that people take the opportunity to fortify their immune systems against the latest variant of the virus. But across the country, people have been slow to get the previous round of shots. That includes people over the age of 75 who face higher risks from COVID.

In Minnesota, the State Department of Health reports just 14% of people were up to date on their vaccines as of June. COVID-19 wastewater levels and hospitalizations in the state have been climbing steadily over the last two months. Joining us right now is the head of the University of Minnesota's Center for Infectious Disease Research and Policy, epidemiologist Dr. Michael Osterholm. It's good to hear your voice.

MICHAEL OSTERHOLM: Good to be with you.

CATHY WURZER: I have lost track of which variants are out there and their acronyms. Which are the most active right now?

MICHAEL OSTERHOLM: Well, welcome to the club, OK? Because these variants continue to emerge quite quickly. What we had been talking about and what is in the vaccine right now is a variant called KP.2. And this was approved several months ago. But since that time, we've now worked from there to KP.3.1.1 as well as KP.3. And even in the last month, we've now begun to see a new variant emerge, LB.1, which is different than the previous ones.

And so this is one of the challenges in dealing with COVID and the virus SARS-CoV-2 is that it rapidly mutates and evolves. And each one of those mutations may or may not add to its ability to evade the immune protection of a human. But unfortunately, it happens enough that they do. So we're always trying to match as close as we can to the variant that has emerged.

CATHY WURZER: So this new updated vaccine, is it fairly well matched?

MICHAEL OSTERHOLM: Well, it's matched enough that it is surely going to give you a real boost in protection. Remember, as we've discussed this many times, Cathy, these are good vaccines, but they're not great. And I mean, we have to be very clear about that. These vaccines will do little to reduce you from getting infected or from transmitting the virus.

But the really important benefit is that they will actually significantly reduce your likelihood of getting seriously ill, being hospitalized, or dying. And right now across the country, we're seeing about 750 deaths a week from COVID up from what was a little over 200 a month and a half ago. Now, that is still far, far below the 20,000 deaths a week we were seeing during the major Delta and Omicron waves. But nonetheless, 750 deaths a week is still a very significant issue for us.

CATHY WURZER: And I'm assuming that these might be folks over a certain age, right? I mean--

MICHAEL OSTERHOLM: They are.

CATHY WURZER: What do you think of the fact that there are not very many folks, say, in nursing homes that are vaccinated? What does it say to you?

MICHAEL OSTERHOLM: Well, I think we've been talking about this for some time. There's two parts to this various debate you might say. One is all about immunology and the science. How well can this vaccine protect or not? The second part is about the sociology. Why do people take vaccines or not?

For example, one of the number one reasons for children under age five to be seen in an emergency room in the last two weeks around the country is due to COVID. Over 5% of all the visits in emergency rooms were kids with COVID. I mean, these were kids that weren't just sick, but they were sick enough they had to be seen in an emergency room.

And so we see very little vaccination in children right now, even though the CDC's Advisory Committee on Immunization Practices has stated clearly kids should get an updated dose of vaccine. And so we have an immense challenge before us to let people know that, in fact, you do need these updated shots.

When you think about a disease like measles where you get vaccinated as a young child, you're protected for life largely. And the virus that causes measles changes very, very little. This is one that's quite different. It's even changing much more frequently than we see with influenza. So you have to take drugs. You have to take your insulin. You have to take other things on a routine basis.

I wish we could find ourselves accepting the idea that every six months at least we should be getting vaccinated against this, particularly those at highest risk for serious illness. As you noted, the older population is, in fact, that group. But as I just pointed out, even kids are getting hit hard with this.

CATHY WURZER: You and I talked a little while back about timing. And you weren't sure when you were going to get your updated vaccine. There's this waning immunity. It's like, what, do I want to wait till September or October? What's your best guidance?

MICHAEL OSTERHOLM: Well, it's a game changer as of Thursday. Once the FDA approved the new KP.2 vaccine, that's the one to get. And it's now available. We are aware that pharmacies throughout the United States have it. They shipped on Thursday. And they are prepared to do that quickly.

So now is just scheduling your appointment, which if a lot of people decide to get vaccinated, which would be a good thing, it may slow down the time for which you could get it. But it's never too late to do the right thing. Get that dose of vaccine. It'll take anywhere from 7 to 14 days before you really start getting the benefit of the immune response to the vaccine.

And right now, we're seeing a lot of COVID. I know more people with COVID now probably than almost any time in the pandemic. And so now is the time to get it. And even, as I said, it won't prevent you from getting infected, it sure can do a lot to reduce the seriousness of your illness.

CATHY WURZER: And help me here, too, because I'm also running into so many people falling victim to COVID since July 4. Can you remind people, how long are you contagious?

MICHAEL OSTERHOLM: Well, welcome to the great unknown. [LAUGHS] And I say that because, in fact, there's been a lot of debate about that. The virologic studies that we have where we actually test people on a daily basis, once they're test positive says by seven days, you have dramatically reduced the virus in you and that, in fact, you may even not even be infectious. And surely by 10 days, that's the case.

If you actually use the tests that we have today, you may actually test positive for an extended period beyond that. But that doesn't mean you're infectious. That means you're just basically excreting out viral debris that was left over from what was happening when the virus was replicating inside of you. And so I tell people, I don't really count on whether the test is positive or not. Once you are infected, ill, and test positive, count on 7 to 10 days, and you will likely be fairly well cleared from that virus. So to me, that's, I think, the rule of thumb.

I do want to add, there's another important note here that the CDC just announced this past week that now as of the 1st of September, there will be funds available for free testing again. You can order free tests. There will be money available for Paxlovid, the drug treatment, for those who do not have health care insurance and otherwise couldn't get it. And there will be free vaccine. So if you're falling in that category again of not having a health care provider that covers it, you can get free vaccines. So we're back to where we were almost eight months ago, fortunately, that no one should be denied access to any of those three.

CATHY WURZER: Because it sounds like we have this surge going on right now. Are we thinking the spread will continue thanks to events like the State Fair?

MICHAEL OSTERHOLM: It will. I think, Cathy, we're now into what I would call the seasons of COVID. People for a long time have wanted to make this be a seasonal virus, i.e. Like influenza. You can count on it occurring from November roughly to February. This is one that is going to constantly be in flux. And it will be a combination of two things and how they merge together.

One is the variant. Is this a new variant that is escaping some of the protection of previous infection or the vaccine? The second thing that is your waning immunity. We know that by four to six months after getting a dose of vaccine or being infected, your immunity begins to wane. And so when you get the two of those overlapping, we're going to see these surges.

There have been 10 surges now in cases that we've had since the pandemic began. And they're distributed through all four seasons. My comment is about this being a seasonal virus is, yeah, it occurs in all seasons.

So, in fact, I think that's the challenge we have right now is that we can't handle this like influenza. We can't just anticipate the winter surge. This is going to occur whenever those two factors link up-- waning immunity and new variants.

CATHY WURZER: OK. Thanks. Always good information. Take care of yourself.

MICHAEL OSTERHOLM: Take care. Thanks.

CATHY WURZER: Dr. Michael Osterholm is an epidemiologist and director of the Center for Infectious Disease Research and Policy at the U of M.