A new, updated coronavirus vaccine is on the way.

This week, the U.S. Food and Drug Administration (FDA) approved and granted emergency use authorization for updated mRNA COVID-19 vaccines. The vaccines come from makers such as Pfizer and Moderna. The new 2024-25 formula includes a monovalent (single) component designed to prevent severe illness from the recent Omicron variant KP.2 strain of SARS-CoV-2.

We talked to two experts at UC Davis Health: Stuart Cohen, the chief of the Division of Infectious Diseases, and Dean Blumberg, the chief of Pediatric Infectious Diseases. They answered common questions about the new COVID-19 vaccine, including when it will be available, who should get the vaccine and why.

How soon will the new shots be available?

Cohen: The FDA just approved the new formula and is debating when exactly to allow the release of the vaccines. The expectation is that they will be available within the next several weeks. This includes both the mRNA vaccines, like Pfizer and Moderna, and a bit later the more traditional protein vaccine (Novavax).

How is this COVID vaccine different than the one we had last year?

Cohen: SARS-CoV-2, the virus that causes COVID, continues to mutate. According to the Centers for Disease Control and Prevention (CDC), the variant called KP.3.1.1 is the predominant strain of virus circulating now. It’s a strain related those known as the “FLiRT” variants.

So, the new vaccines will be targeting a different strain of the virus than last year’s vaccine. The mRNA vaccines will target the KP.2 strain, which was dominant in the spring. The protein vaccine (Novavax) will target the JN.1 strain. All three vaccines will be active against the current variants.

Blumberg: These new strains are as different from [the original] Omicron as Omicron was from the ancestral strain. They’re pretty far apart evolutionarily. The updated vaccine is a much better match for the currently circulating variant. That match is about 80 percent. We expect it to be much more effective.

Even if you had COVID before or received COVID vaccines, the immunity wanes over time and the virus mutates.What are the CDC recommendations for who should get the 2024 COVID vaccine?

Cohen: The CDC recommends that everyone ages 6 months and older receive an updated 2024-25 COVID-19 vaccine. The new vaccine will help protect against the potentially serious outcomes of COVID-19 this fall and winter. This is regardless of whether they have ever previously been vaccinated with a COVID-19 vaccine.

It is important to understand that even though the disease has become less severe, people who receive vaccines have a milder illness and a lower risk for long COVID than those who have not been vaccinated.

If someone previously had COVID, do they still need to get the vaccine?

Cohen: Yes, immunity wanes over time and the virus mutates. That is the reason the CDC made its recent recommendation.

Blumberg: If you’ve had COVID in the past three months, you’re likely protected. But the immunity seems to wear off after about three months. I do recommend waiting those three months before getting the vaccine, because that will prolong your time that you’re protected. For example, if you got COVID in August, then why not wait until November to get your updated vaccine? Then you’re protected for another four to six months through the winter.

Flu season will be here in a few months. Why should someone get the flu or COVID vaccine? The SARs-CoV-2 virus that causes COVID-19 has changed since the beginning of the pandemic

Cohen: There are several reasons to get the vaccines. Both COVID and influenza can be serious diseases, leading to hospitalization, long term symptoms and even death. Even though these vaccines do not fully prevent people from getting infected, they do decrease the risk that those infections will cause severe outcomes.

Data from the CDC continue to show the importance of vaccination to protect against severe outcomes of COVID-19 and flu, including hospitalization and death. In 2023, more than 916,300 people were hospitalized due to COVID-19 and more than 75,500 people died from COVID-19. During the 2023-24 flu season, more than 44,900 people are estimated to have died from flu complications.

Can someone get the COVID and flu vaccine on the same day?

Blumberg: You can get the influenza vaccine and COVID vaccine at the same time. You can get them simultaneously.

You can also get your COVID vaccine at the same time as you’re getting your vaccine for RSV (respiratory syncytial virus). Remember that RSV vaccines are recommended for those who are older and certain younger groups who are at more risk of severe disease.

Is the new vaccine safe?

Blumberg: The U.S. has a robust vaccine safety system. There is no question the benefits of vaccination far outweigh any adverse effects.

Experts encourage as many people as possible to get the new vaccine, even kidsKids often have mild symptoms. Do they still need a COVID vaccine?

Cohen: While illness is usually mild in children, it can be more severe on occasion. Children are also a chain in the transmission of SARs-CoV-2. The risk of the vaccine is less than the risk of the disease.

Is there any recommendation for which vaccine to get this year? Does it matter which one you had before — Pfizer or Moderna or Novavax?

Cohen: There is no clear preference. Most people have taken the mRNA vaccines, and they will be available sooner. But for the people who do not want an mRNA vaccine, waiting for Novavax is an option.

The fear from catching COVID and its impact seems to have subsided. As an infectious diseases expert, what would you like people to keep in mind?

Cohen: People continue to be hospitalized from COVID, and there were approximately 75,000 deaths last year. Everyone has COVID fatigue, but being smart about taking the right precautions will help determine whether someone will get severe disease. The vaccines have been proven safe and effective. When case numbers are high, use of a mask could be protective. The vaccine just furthers the protection by decreasing disease severity, if one does get infected.

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