Healthy Returns: What to know about the latest round of Pfizer, Moderna Covid vaccines

A version of this article first appeared in CNBC’s Healthy Returns newsletter, which brings the latest health-care news straight to your inbox. Subscribe here to receive future editions.

It’s that time of the year again. A new round of Covid shots is on its way to Americans. 

The Food and Drug Administration last week approved updated mRNA-based vaccines from Pfizer and Moderna amid a relatively large summer surge of the virus. Here’s what you need to know, including how the shots are different this time around, who is eligible, where to get a vaccine and more. 

U.S. health officials have long told patients to expect annual updates to Covid shots as the virus mutates into new strains that can dodge the immunity people develop from previous vaccinations or infections. It’s similar to how the U.S. rolls out new flu shots each year. 

This time, the shots from Pfizer and Moderna are designed to target a strain called KP.2, a descendant of the highly contagious omicron subvariant JN.1 that began circulating widely in the U.S. earlier this year. 

KP.2 was the dominant strain of the virus in May, but now only accounts for roughly 3% of all U.S. cases as of Aug. 17, according to the latest Centers for Disease Control and Prevention data.

Still, both Pfizer and Moderna have said that their new vaccines can produce stronger immune responses against other circulating variants, such as KP.3, than last year’s round of shots targeting the omicron strain XBB.1.5 can. 

KP.3 accounts for nearly 17% of U.S. cases, while a related strain called KP.3.1.1 makes up almost 37% of cases, CDC data says. 

“The good news is so far that the updated vaccine closely matches the KP.3 family of viruses that continues to grow in dominance,” CDC Director Mandy Cohen told reporters during a briefing on Friday. 

The CDC recommends that everyone 6 months and older receive one dose of the new Covid vaccine. 

To maximize protection, people should wait at least two-to-three months since their last Covid vaccination or infection before getting one of the updated shots, Dr. Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research, told NPR last week. 

Health officials have also stressed the importance of high-risk individuals keeping up with their Covid vaccinations. That includes people 65 and older and those who are immunocompromised or have serious medical conditions. 

Following the approval last week, Pfizer and Moderna both said they expected their new shots to be available in pharmacies, hospitals and clinics across the U.S. “in the coming days.” 

Walgreens said patients can now schedule vaccination appointments at stores nationwide, according to a statement on Thursday. Appointments for people ages 12 and above are available starting on Sept. 6, the company noted. 

Meanwhile, CVS’ online vaccine scheduler offers appointments for as early as Wednesday. Rite-Aid’s own scheduler shows appointments for early September. 

The CDC plans to relaunch its shot appointment locator once the jabs are more widely available. 

The FDA’s Marks told NPR that he would likely get vaccinated “in as timely a manner as possible” because the variant targeted by the updated shots is “reasonably close” to the strains currently circulating in the U.S. 

But he said some people could consider waiting until September or October if they want to maximize their protection from the vaccine through a potential winter Covid surge and the holiday season. 

“Getting vaccinated sometime in the September to early October time frame seems like a pretty reasonable thing to do to help bring you protection through the December/January time frame,” Marks told the outlet. “It doesn’t, like, suddenly stop. This is not like something that suddenly cuts off at three or four months. It’s just that the immunity will decrease with time.”

Most private insurance plans, as well as the federal Medicare and Medicaid programs, cover the cost of Covid vaccinations.

Children can also receive free shots through a federally-funded program called Vaccines for Children. 

Meanwhile, the CDC’s Bridge Access Program, which was designed to provide free Covid shots to underinsured and uninsured Americans, will not reopen this year. 

But the CDC has found $62 million in funding for state and local immunization programs to cover the cost of Covid vaccines for uninsured and underinsured adults, Dr. Demetre Daskalakis, director of the CDC’s National Center for Immunization and Respiratory Diseases, told reporters during the briefing last week. 

Novavax has filed for authorization of a new protein-based shot targeting JN.1. The company said its vaccine should provide protection against descendants of that strain, such as KP.2.3, KP.3, KP.3.1.1 and LB.1. 

In a statement last week, Novavax said it is working “productively” with the FDA as the agency completes its review. Novavax expects its shot to receive authorization in time for peak vaccination season in the U.S.

Feel free to send any tips, suggestions, story ideas and data to Annika at annikakim.constantino@nbcuni.com.

Earlier this month, I began testing out a new continuous glucose monitor from the diabetes management company Dexcom. It’s called Stelo, the company’s first product available over the counter without a prescription. 

A continuous glucose monitor, or a CGM, is a small sensor that sticks through the skin and measures glucose levels in real time. Glucose is a type of sugar people receive from carbohydrates, and it’s the body’s primary energy source. 

Everyone’s glucose levels fluctuate, but high levels can lead to serious health problems like diabetes, heart disease and kidney disease over time. CGMs are typically prescribed to patients with diabetes so they can monitor their glucose levels and get alerted to emergencies. 

Stelo is primarily designed for adults with prediabetes or Type 2 diabetes who do not use insulin, though people without either condition can also get it. The device launched in the U.S. on Monday after the Food and Drug Administration approved it in March. 

Users can buy a one-month supply of Stelo online for $99, or sign up for an ongoing subscription at $89 a month. Patients can also use their flexible spending accounts and health savings accounts to pay for it, Dexcom said. Dexcom is working with Amazon to fulfill Stelo deliveries.

I’ve been using the sensor for a couple weeks, and I’ve already learned a lot. I think it’s an easy product to try for an approachable introduction to understanding your glucose data. 

Once your sensors arrive at your home, everything you need is in the box. First, you apply the sensor to your arm and pair it with the Stelo app. 

The app walks you through exactly what to do, so there’s no need to be nervous. I cleaned the back of my right arm, placed Dexcom’s applicator there, pressed the button and the sensor popped right on. There’s a small needle in the applicator that can look a little unnerving, but I didn’t feel a thing. 

The CGM connects to the Stelo app via Bluetooth, and then it takes about a half hour to warm up. 

When I got to this step the first time, I encountered some problems. Once my device had warmed up, I got an error message that said “Brief Sensor Issue.” It told me not to take off the CGM, and said the issue would resolve within up to three hours. I left it on for the rest of the day, but by evening, I noticed some light bleeding around the sensor. 

I decided to take that CGM off, which you can do by peeling it like a sticker. I tried again with a new sensor on my other arm, and that one warmed up and worked correctly. I haven’t had any more trouble with bleeding. If you encounter any issues with Stelo while you’re using it, you can message the chat feature on the website to ask questions or get a replacement if necessary.

On the whole, I think the sensor is quite easy to wear. It’s waterproof, and it lasts for 15 days at a time (a new record for Dexcom). It’s gray, around the size of a quarter and about half an inch thick. Though it snagged from time to time when I was pulling on long sleeves, I felt like I could wear anything over it. I didn’t notice it while sleeping, either.  

I’ve also found Stelo’s app interface easy to use, and I think Dexcom does a good job presenting the data in a way that doesn’t feel overwhelming or confusing. 

On the Stelo homepage, you’ll see your latest glucose reading, which is updated every 15 minutes. You’ll also see a graph of your readings each day, which includes a shaded green area to indicate your “Target Range.” That span is where Dexcom encourages users to try to keep their glucose levels, based on existing medical standards. 

The tab next to the home page is the “Events” page, which is where you can log meals, activity, fingersticks, which are another way to measure blood sugar, or other notes. You don’t need to log every little detail of your day, but Jake Leach, chief operating officer at Dexcom, told me it’s important to log when you’re experiencing a glucose spike. 

Glucose spikes occur when the amount of sugar present in the bloodstream rapidly increases and then decreases. This often happens after eating. Stelo will notify you when you’re experiencing a notable spike, and logging an entry can help you reflect on what might be causing them, Leach said. 

If it’s your first time using a CGM, I definitely recommend reading through the articles in the app’s “Learn” tab. They’re short, and they help break down concepts like what glucose is, what affects it and why it matters.

In just a couple weeks, I’ve learned a lot about how my body responds to food and activity with Stelo. And now that the tech is available over-the-counter, I wouldn’t be surprised if CGMs become the next big tech wearable in the U.S. 

Feel free to send any tips, suggestions, story ideas and data to Ashley at ashley.capoot@nbcuni.com.