What You Need to Know About the Flu, COVID-19, and RSV Vaccines

November 2023

As the days grow shorter and temperatures fall, many people start to experience sniffles, coughs, and runny noses. But not all cold-weather bugs are created equal. While many viruses are mild, others are much more serious, carrying the risk of hospitalization or even death.

Fortunately, vaccines are available to prevent three of the most serious viruses you’re likely to encounter this winter — COVID-19, influenza, and respiratory syncytial virus (RSV). None of these vaccines guarantee that you won’t catch the virus, but each vaccine reduces the risk of getting sick. And even if you do develop an infection, your chances of hospitalization, serious complications, or death will be lower.

It’s important to know who is eligible for each of these vaccines and which vaccines public health experts recommend you receive to remain as healthy as possible throughout this fall and winter.


The CDC recommends that everyone aged six months and older get the annual flu vaccine. Many symptoms overlap between colds and the flu, but the flu is far more dangerous than a typical head cold. The severity of the flu varies from one year to the next. During the 2011-2012 season, about 12,000 people in the U.S. died from the flu; during the 2017-2018 season, around 52,000 died from the flu.

Strategies to prevent COVID-19, like social distancing and masking, made the 2021-2022 flu season almost nonexistent, with about 700 deaths from the flu — the lowest ever. But the gradual return to pre-pandemic activities means the flu virus has returned full time too.

Those at highest risk for severe influenza and its complications include …

  • Adults aged 65 and older, infants, young children, and pregnant women;
  • People who are immunocompromised and people with disabilities; and
  • People with chronic health conditions, especially asthma, heart disease, diabetes, HIV, cancer, kidney disease, and neurologic conditions.

Getting the seasonal flu vaccine is particularly important for people in these groups.

Infants and children getting their first-ever flu vaccines will need two doses, but everyone else needs only one dose. A couple of additional options exist for that dose beyond the usual flu shot.

Those who prefer or need an egg-free vaccine can get the cell-based flu vaccine for children aged six months and older or the recombinant flu vaccine for people aged 18 and older, which is also recommended for older adults who need extra protection.

People who want a needle-free option can get the live nasal spray flu vaccine, approved for ages 2 to 49. They can also get the jet injector flu vaccine, approved for ages 18 to 64, which shoots a high-pressure stream of fluid into the arm instead of using a needle. However, the live nasal vaccine should not be given to people who are pregnant, are immunocompromised, or have certain medical conditions.

People aged 65 and older should get one of the three vaccines designed specifically to give more protection to older adults because the immune system gets weaker with age:

  • The high-dose quadrivalent vaccine contains four times more antigen than standard flu vaccines.
  • The recombinant quadrivalent vaccine is made without eggs and is more effective in older adults than standard flu vaccines.
  • The adjuvanted quadrivalent vaccine contains an adjuvant, an extra ingredient made of naturally occurring oil, that strengthens a person’s immune response to the vaccine.


The new public health approach to COVID-19 mirrors what we do for the flu, even though COVID-19 is much more serious than the flu, with an annual COVID-19 vaccine based on whichever variants have been circulating most recently.

Therefore, the updated COVID-19 vaccines are no longer boosters because they don’t provide protection specifically against the original SARS-CoV-2 virus. Instead, they convey protection against the most recent subvariants and thus better protect against the versions of the COVID-19 virus currently making people sick. The CDC recommends that everyone aged six months and older get the new COVID-19 vaccine to reduce their risk of COVID-19 this winter.

There are three different COVID-19 vaccines available, and you can get any of these three vaccines, no matter what vaccine you originally received or what boosters you’ve gotten. The vaccine is especially important for older adults and people with weakened immune systems or certain chronic conditions, including diabetes, high blood pressure, and obesity.

RSV vaccines now available

Chances are you’ve already had RSV many times in your life. RSV season runs alongside most flu seasons, starting in the fall and peaking in the winter. For most people, RSV feels like an ordinary cold, with a runny nose, reduced appetite, coughing, sneezing, and maybe a fever. But RSV can be especially dangerous, and even deadly, in babies, older adults, and people with weakened immune systems. This is the first year that it’s been possible to prevent RSV with a vaccine.

Older Adults. Two very similar RSV vaccines were approved by the FDA in 2023 for adults aged 60 and older. Every year, about 60,000 to 160,000 older adults are hospitalized for RSV infections, and about 6,000 to 10,000 adults die from RSV complications. Those at highest risk are adults with chronic heart or lung disease, those living in nursing homes or long-term care facilities, and those with weakened immune systems or certain other underlying medical conditions.

The CDC recommends that all older adults talk with their doctors about whether this vaccine would benefit them. The vaccine is the only way to prevent RSV aside from usual hygiene practices, like washing hands, covering coughs and sneezes, and cleaning surfaces. One dose of either vaccine is about 83% to 89% effective in preventing lung infections during the first RSV season after receiving the vaccine.

Babies. The other group at high risk from RSV is babies under one year old, especially those under six months old. That’s because their airways are so small that it’s harder for them to breathe when their airways swell with inflammation. There are no RSV vaccines approved for kids, but there are two other ways to protect infants against RSV.

A parental RSV vaccine can be given between 32 and 36 weeks of pregnancy so that antibodies can be made by the parent and travel across the placenta to the developing baby. This vaccine is about 82% effective in preventing lung infections for a baby’s first three months and about 69% effective for their first six months.

Alternatively, parents can wait until after their babies are born and give infants under eight months old an RSV antibody immunization called nirsevimab. Antibodies are proteins made by white blood cells that fight off viruses and bacteria. Nirsevimab is an injection of antibodies against RSV. It’s about 75% effective in preventing RSV for five months in babies.

One dose of nirsevimab is also recommended for children aged 8 to 19 months who are entering their second RSV season and at high risk for severe RSV disease. Children with this increased risk include children who are born prematurely and have chronic lung disease, children with severe cystic fibrosis, children who are severely immunocompromised, and American Indian and Alaska Native children.

Can I get the COVID-19, flu, and RSV vaccines at the same time?

If you’re an older adult, you’re eligible to get all three vaccines. However, no studies have tested the use of all three vaccines at the same time, so public health experts don’t recommend it. Fortunately, scientists have studied the use of the flu and COVID-19 vaccines at the same time and discovered that it’s safe to get them together.

You might be slightly more likely to have side effects if you receive the flu and COVID-19 vaccines at the same time. One study found that people who got both together were a little more likely to have fatigue, headaches, and muscle aches than people who received the COVID-19 vaccine alone. But getting your flu and COVID-19 vaccines together can also save time. If you decide to get them separately, you don’t need to wait for any amount of time between one and the other.

Some people in the RSV vaccine clinical trials received the flu vaccine around the same time and did not have any problems, but the use of the RSV and flu vaccines together has not been studied closely since the RSV vaccine is new. Right now, experts recommend getting the RSV vaccine at least two weeks before or two weeks after receiving the flu and COVID-19 vaccines.

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