A new type of flu vaccine called mFlusiva is expected to be available for adults 50 and older this flu season. The Food and Drug Administration (FDA) approved it in early August, making it the first flu shot to use the same mRNA technology used in COVID-19 vaccines.

Like other seasonal flu vaccines, mFlusiva is designed to protect against the flu strains expected to circulate this fall and winter. Its potential advantage is that mRNA technology can be updated and manufactured more quickly as those strains evolve.

Flu vaccines are updated annually and are given once a year, with September and October considered the best times to get vaccinated.

Flu can be serious, particularly for older adults and people with certain chronic conditions. mFlusiva may offer hope for a faster response for the most vulnerable populations. Dr. Benjamin Missick, a family medicine physician at Novant Health Blakeney Family Physicians in Charlotte, shared more about the new flu vaccine.

What makes this new flu vaccine different?

This vaccine is an mRNA vaccine. Traditional vaccines can take some time to manufacture. Because the influenza virus is constantly evolving, the effectiveness of the traditional flu vaccine may not be as high from year to year. By comparison, the mRNA vaccine was shown to be 26.6% more effective than the traditional flu vaccine in clinical trials.

Can you explain how mRNA vaccines work?

Yes. We first saw mRNA vaccines become prevalent during COVID-19, when they were mobilized to quickly respond to the pandemic. mRNA vaccines deliver genetic instructions that help the body recognize the flu. They do not contain influenza virus.

Why could this technology be especially useful for influenza, given that flu strains change from season to season?

As we saw during COVID-19, with boosters coming out as the virus evolved into different strains, mRNA technology can make it possible to update vaccines more quickly when viruses change. That could be especially helpful for the flu, which evolves quickly.

Like other seasonal flu vaccines, mFlusiva is still designed around the strains we expect to circulate most widely, but mRNA technology gives us more flexibility to respond as strains evolve due to the fast production time.

Those who are over 65 have traditionally received high-dose flu vaccines. Is this new mRNA vaccine a better option?

For those ages 65 and older, the mRNA vaccine has been shown to be a comparable option to the high-dose vaccine, so either is a good option. That’s good news because it gives people another effective choice. If your pharmacy doesn’t have the mRNA vaccine in yet, you can confidently get the high-dose vaccine you’ve received in the past.

What side effects should people expect, if any?

One could expect muscle aches, fever, injection site pain, headache, chills and/or fatigue. Not everyone will experience these side effects, and not everyone will have them with the same severity. In the clinical trial of this vaccine, any side effects lasted about two days. You can prepare for the potential of side effects by clearing your schedule for a day and considering over-the-counter options such as Tylenol and ibuprofen.

How should patients weigh the risks and benefits of this vaccine?

The risk of getting the flu far outweighs short-lived side effects. The vaccine is a safe way to prevent what can be a dangerous illness for people 50 and over, or those with underlying conditions.

Consider that if you’re 50 and older and have underlying risk factors such as heart problems, a history of smoking, asthma or Type 2 diabetes, you’re more likely to develop heart failure or pneumonia once you contract the flu. We tend to think of the flu as a seasonal hazard, but in reality, it can lead to severe complications.

How can I find out if my pharmacy or doctor’s office carries the new flu shot?

Ask your doctor or call your local pharmacy. Many should be carrying it once it becomes widely available.

What should I do if the new mRNA flu vaccine isn’t available to me?

If you are older than 65 and this vaccine is not available to you, get your regular, high-dose vaccine.

If you are 50 to 64 and this vaccine is not available to you, get the regular recommended seasonal flu vaccine. If you are younger than 50, get the seasonal flu vaccine recommended for your age group.

Beyond vaccination, what are the best steps you can take to avoid getting the flu?

• Avoid crowds.
• Don’t go out if you’re sick.
• Schedule appointments to get your recommended yearly vaccines. If you aren’t sure what those are, ask your primary care provider which vaccines you need this year to be up to date with the American Academy of Family Physicians Vaccine Schedule.
• Practice good hygiene — always wash your hands with warm water and soap.
• Sanitize high-contact surfaces, like doorknobs.
• Wear a mask, especially if sick. It certainly won’t hurt you, and it will protect others.
• Ensure that any caregivers are vaccinated. For example, if a grandparent takes care of your child, make sure they’re vaccinated. If a healthcare worker lives in the house, make sure all of you are vaccinated to avoid transmission of disease to and from their workplace.

Key takeaway: The flu can cause serious illness and death, and although the medically vulnerable are usually most at risk, getting vaccinated can help reduce the spread of illness in the community. If you’re 50 or older, you can ask your doctor or pharmacist about mFlusiva as a new option for protection against the flu.

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