JOHN YANG: When federal health officials approved a new COVID booster earlier this month and recommended it for anyone six months or older, doses were expected to be available in pharmacies within days.

But two weeks later, many people are having trouble finding the vaccine.

And if they do find it, some are having trouble getting insurance to pay for it.

And some nursing homes, which are more vulnerable to COVID, haven't even begun vaccinating residents yet and may not until November.

Katelyn Jetelina is a University of Texas epidemiologist and author of the popular newsletter Your Local Epidemiologist.

Katelyn, why is the rollout of this new booster a little messier than the previous rollouts?

KATELYN JETELINA, Author, "Your Local Epidemiologist": Yeah, it's been messy, to say the least, like you said.

And this is because of a massive shift coming out of the emergency that COVID-19 vaccines are now commercial.

So in other words, the U.S. government is no longer responsible for purchasing or distributing these vaccines.

So this means we have now multiple payers i.e.

Insurance companies and changes to the delivery system, which has unfortunately resulted in this slow rollout and fragmented inequitable and, quite frankly, imperfect system.

General Perna was in charge of it during the pandemic.

He was the chief operation officer of Operation Work Speed.

And I think a lot of people underappreciate, including me, the massive task of getting 330,000,000 people a vaccine quickly.

I think it was 24 hours after the initial rollout in December of 2020, and it saved lives.

JOHN YANG: This week, the Health and Human Services Secretary, Xavier Becerra, called in the insurance company executives to remind them or get them to recommit to paying for these vaccines.

Is that also a factor or a result of this moving from the government to commercial?

KATELYN JETELINA: Yeah, commercial is very confusing because COVID is also not our normal flu vaccine.

But bottom line to the general population, no one should be paying for a COVID-19 vaccine.

Private insurance companies are mandated to cover this vaccine with no copay.

Now insurance companies are no longer required to pay out of pocket.

So this may mean you have to get your vaccine at your doctor's office opposed to a pharmacy that's not in network and then under an uninsured people, CVS and Walgreens are required by federal law to give you a vaccine at no cost.

Thanks to this new federal bridge program.

JOHN YANG: There was a Kaiser Family Foundation poll that found that 46% of those surveyed said they either definitely or probably will get this new booster.

And that's above what it was for the previous booster at the beginning of the year, but also below what it was for the initial vaccine.

Is that good news or bad news that number?

KATELYN JETELINA: You know, I think it's good news.

I'm actually pleasantly surprised it's about 50 percent.

That's about what we see with the flu vaccine every year pre pandemic and during pandemic.

And I think that if we can get up to those flu vaccine numbers, we're a whole lot better than we did last fall, which was about one in four Americans getting their fall boosters.

JOHN YANG: You talked about the three vaccines that are out there this fall for people COVID, seasonal flu, and RSV, the respiratory virus.

Walk us through what people should be thinking about this, about when to get them, which ones to get.

Can you mix them?

Can you get two or all three at the same time?

Let's start with COVID.

KATELYN JETELINA: Yeah.

So everyone over six months and older are eligible to get the COVID-19 vaccine.

You can get it with your flu.

You can also get it with your RSV vaccine, which cuts down the number of visits you have to the pharmacy or the doctor's office.

The most challenging thing with COVID-19 vaccines is timing.

When should you get your COVID-19 vaccine?

And this is dependent on, of course, your risk calculus.

How long do you want to wait?

It depends on how at risk you are.

So those over 65, I tell people to get their vaccine right away, and it also depends on the last time you were infected.

So we suggest people getting their vaccine about at least three to four months after infection.

JOHN YANG: And the RSV vaccine.

KATELYN JETELINA: People are eligible if they're over the age of 60.

And pregnant people are now eligible to have the vaccine in their last trimester of pregnancy to help their newborn.

And we also have monoclonal antibodies.

And this isn't a vaccine, but it's more like antibody medication that little kids under eight months old can get in their first RSV season.

RSV doesn't wane as quickly the protection doesn't wane as quickly as COVID-19 or flu vaccine.

So you should get it right away, and it'll be durable throughout the season and even maybe into next season.

We're waiting to see data on that.

JOHN YANG: Seasonal flu vaccine, there's always, or at least I've heard this debate about whether you get it early or get it late.

What's your recommendation?

KATELYN JETELINA: Yeah, so everyone over six months is eligible for flu vaccine.

It does wane, I would say not as quickly as COVID-19.

And so, particularly among older adults, we suggest getting the vaccine in October.

So all this is really confusing to keep in mind, but I think the bottom line is if you're eligible, get the flu COVID and RSV vaccine before Halloween, and you should be pretty darn protected going into this winter.

JOHN YANG: Katelyn Jetelina, your local epidemiologist.

Thank you very much.

KATELYN JETELINA: Thanks for having me.