MILWAUKEE — Some Wisconsinites can now roll up their sleeves — again — for a third dose of COVID-19 vaccine, the state announced this week.

The Department of Health Services on Monday released its guidelines for coronavirus booster shots, after the CDC made its final decisions last week on who can get another Pfizer shot right now. The rollout is prioritizing people who are at a higher risk based on their age, medical conditions or jobs.

Here, we break down the key questions about boosters in the Badger State — whether you’re trying to figure out if you’re eligible, or just want to make sense of the science behind the booster debate.

Who’s eligible for a booster shot now?

The latest guidance means some groups who are at higher risk — either of catching COVID-19 or getting really sick from the virus — are now eligible to get a third Pfizer dose. 

The DHS recommends that some groups SHOULD get a booster dose, including:

• People 65 years and older

• Residents in long-term care settings

• People aged 50-64 with certain underlying medical conditions that put them at risk 

And other Wisconsinites MAY get a booster dose, thinking about their individual risks and benefits:

• People aged 18-49 with certain underlying medical conditions

• People aged 18-64 who are at increased risk of COVID-19 exposure and transmission based on their job or institutional setting

So far, only those who got the Pfizer vaccine for their first two doses are able to get a booster shot. If you’re eligible, you should get the booster six months after your second dose, federal and state guidelines recommend.

There’s a long list of medical conditions that qualify for the booster shots — based on the CDC’s findings of who is most vulnerable to getting severe COVID-19. Patients with cancer, diabetes, heart conditions, obesity and lung disease are all included in the recommendation.

And the list of jobs that qualify based on exposure risk includes a range of frontline workers — from first responders and education staff, to corrections officers and grocery store employees. This list could be updated in the future, the DHS clarified in its guidance. 

But haven’t some people already been getting extra doses in the state?

That’s right. In August, the DHS gave the green light for some Wisconsinites to get third mRNA vaccine doses — that means either the Pfizer or Moderna shots — if they have certain health problems that weaken the immune system.

That means patients with some conditions — including organ transplants, HIV, immunodeficiency and stem cell transplants — have been getting their extra shots for more than a month now. 

But the DHS clarified that we should think of this earlier round as “additional doses” rather than boosters. Research has shown that people with weakened immune systems may not build up a strong enough response after two doses of a Pfizer or Moderna vaccine — so the additional dose helps get them to the standard level of immune protection.

Booster shots, on the other hand, are meant to revamp protection for people who may have had a strong response after two doses, but have seen their immunity wane over time.

Why do scientists think some people need a booster dose?

Research has shown that the vaccines still offer strong protection against the worst symptoms of COVID-19 for most people — even as delta has surged, and many are months out from their original vaccination dates. The vast majority of coronavirus hospitalizations and deaths right now are coming from unvaccinated people.

Still, the high effectiveness levels that we see soon after getting our shots may dip a bit over time, studies have shown. 

And those declines are the strongest in the groups who are first in the booster line right now: “Older and sicker people,” as Ben Weston, medical director of the Milwaukee County Office of Emergency Management, said at a Tuesday briefing.

One CDC study from August found that vaccine effectiveness in nursing home residents dipped from around 75% to 53% after delta became the dominant strain. 

Giving those vulnerable groups an extra immune nudge can help protect them from getting really sick amid our delta surge. And boosting protection for those who work with high-risk groups, or with the public in general, can help cut off the virus from spreading, Weston said. 

The boosters are another tool to “help people who are vaccinated maintain the highest possible level of immune system protection for as long as possible,” state epidemiologist Ryan Westergaard said in a DHS statement.

How do I get a booster if I’m eligible?

Getting your booster shot won’t look much different from getting your first two doses.

You can get a booster dose from “just about any place” you can get a COVID-19 vaccine, Weston said.

The Milwaukee Health Department will now offer boosters at its community vaccine clinics, Mayor Tom Barrett said at the briefing. Other local sites — including the Milwaukee VA and Hayat Pharmacy — have started getting booster shots in arms, too.

CVS and Walgreens both announced that they are administering third doses and encouraging eligible people to make an appointment. 

As always, you can check vaccines.gov to search for nearby appointments. You may want to confirm that your vaccination site has the Pfizer vaccine and is offering boosters — as well as whether you need to bring any proof that you’re eligible. 

What do the side effects look like?

Side effects for the third dose seem to be similar to the first two doses, CDC Director Rochelle Walensky said at a briefing this week. 

Overall, the extra doses are “well-tolerated,” she said. Side effects tend to be mild and fade away quickly.

The CDC this week released monitoring data from more than 22,000 people who had gotten third doses already. The most commonly reported reactions were injection site pain (71%), fatigue (56%) and headache (43%), according to the report.

All of that is pretty similar to the effects found in Pfizer’s clinical study of booster doses.

Is the booster shot different from the first two doses?

Nope. The boosters that are currently going into arms are just a third dose of the same material. 

Pfizer and Moderna both have some clinical trials underway to test out booster shots that are tailored to specific viral variants, including delta. 

But not everyone is convinced that we need such a specific shot — especially since the delta variant’s spike protein, which is the target of the vaccine, looks pretty similar to the spike from the original virus, as Vox explains.

What if I got a Moderna or Johnson & Johnson vaccine?

Right now, boosters are only authorized for the Pfizer/BioNTech vaccine. 

Booster doses for Moderna and Johnson & Johnson recipients could be added in the future. But health officials are still waiting to review the data for these other vaccines, Walensky said this week.

Both Moderna and J&J have released some promising preliminary results that third doses could provide a helpful immune boost. Infectious disease expert Anthony Fauci has said that the necessary data for the full review process are expected in the coming weeks. 

According to a recent CDC report, the Moderna vaccine’s effectiveness held up well over time: It was still around 92% effective at preventing hospitalizations after four months. The Pfizer shot dipped to 77% effectiveness against hospitalizations in that same time period, the study found. 

What’s with all the back-and-forth about boosters?

If you’ve been confused about the booster rollout recently, you’re probably not alone. 

Walensky herself said this week that she recognized the confusion with the booster rollout, and emphasized that federal officials were “evaluating this science in real time.” 

The U.S. government had previously said that everyone would be getting boosters starting in the fall. But the rollout got slimmed down, with the FDA and CDC deciding that not everyone needs another dose just yet.

The approval for booster shots, like for the vaccines in general, comes with a lot of different steps. Between the FDA, the CDC and the scientific panels that help each of them make decisions, there was some disagreement in recent weeks — especially over whether to include people who have higher exposure risk because of their jobs.

But the final CDC guidance from Walensky gave these groups the go-ahead to get a booster if they want. 

Depending on what kinds of data we’re seeing in the coming months, the booster list could grow. Eventually, everyone may become eligible for an extra dose to lock in their immune response.

But booster doses are “not the key to getting us out of this pandemic,” Weston emphasized. Getting those first shots to people who remain unvaccinated is still the priority — and U.S. officials say we have plenty of doses to handle the demand from boosters on top of the regular vaccine rollout.