It’s that time of the year: fall, which I think of as flu vaccination time.
I always think getting a flu vaccine is a good idea for most older adults. In these COVID pandemic times, I think it’s even more important. So I agree with the Centers for Disease Control (CDC), which is urging that people get vaccinated against influenza early in the fall (before the end of October 2023).
Now, vaccination against seasonal influenza can seem like a bit of a tricky topic. Many older adults are skeptical of the need to get a yearly vaccination against influenza. They aren’t sure it will help. Or they think that the vaccination will actually give them a mild case of the flu. Or they just don’t like needles.
Or maybe they aren’t sure which type of seasonal flu shot to get: the regular one or one of the newer “stronger” versions, designed for older adults?
And now that we have COVID-19 to contend with, vaccination for seasonal influenza might feel even more confusing for people.
Don’t let yourself be confused. In this article, I will share with you what I know about influenza vaccination and what I’ve learned about influenza in COVID times. I also have updates on the stronger flu vaccines that are now recommended for older adults.
This year, I agree with the CDC that it’s important for people to get their seasonal flu shot, and if you are an older adult, I recommend getting one of the three flu vaccines specifically recommended for older adults. (See below for more on these!)
Note: If you are age 65 or older and it’s been more than 2 months since your last COVID booster, you may be able to get your COVID fall booster shot at the same time. (For more on the fall 2023 COVID booster, see COVID & Aging Adults: 2023 Updates)
In “normal” pre-COVID times, the Centers for Disease Control (CDC) estimates that every year, influenza affects 9-45 million Americans, causes 140,000-810,100 hospitalizations, and results in 12,000-61,000 deaths. In most years, influenza vaccination does help reduce hospitalizations and deaths (I go into details below).
And now this fall, this will be our fourth winter dealing with COVID-19 as well. (Plus there is now RSV!) As of September 2023, we still have 500-900 people dying of COVID every week, most of whom are people over age 65. We don’t know for sure what will happen this fall, but since COVID seems to spread more when people are indoors and in proximity to the exhalations of others, it’s likely that COVID will get worse again this winter.
So this year, it’s important to do what you can to reduce respiratory illness, to protect yourself, and to protect others. And getting vaccinated against influenza is one of the things we can do.
In fact, I’m about to go get mine. As a healthy woman in her 40s, I’m not that concerned about getting dangerously ill from influenza. Instead, I get my annual flu shot because I want to minimize my chance of getting sick and perhaps exposing my older patients to influenza.
Here’s what I’ll cover in this article:
- The basics of influenza and vaccination against the flu
- What we know about influenza and COVID-19
- What to know about flu shots for older adults & the CDC’s new recommendations specifically for older adults
- What’s new and resources for the 2023-2024 flu season
- Which influenza vaccination is probably best for most older adults
- What to do if your older parent or relative is unwilling or unable to get vaccinated
- Whether it’s more important to get a flu shot or a COVID vaccination (or a booster)
The basics of influenza and vaccination against the flu
Q: What is influenza?
A: Influenza is a contagious respiratory viral illness, caused by influenza A or influenza B virus. It usually causes symptoms such as sore throat, stuffy nose, cough, fever, and body aches. In the Northern hemisphere, influenza is most common in the winter. Peak influenza activity usually occurs between December and February, but it can start as early as October and occur as late as May.
In “uncomplicated” influenza, the flu causes symptoms similar to — but usually worse than — a very bad cold, and then these get better over 5-7 days. Most people who catch the flu experience uncomplicated influenza, with some people experiencing more significant symptoms than others. In fact, some people (14%, in one study) will catch the flu and shed some flu virus, yet not report any symptoms!
However, influenza does sometimes cause more serious health problems, which we call “complications.” These are more likely to happen to people who are older, have other chronic conditions, or have a weakened immune system.
The most common complication of influenza is pneumonia, which means a serious infection of the lungs. Such cases of pneumonia are sometimes purely viral. But it’s more common for them to be caused by bacteria, who are able to infect the lungs due to the body being weakened by influenza infection.
Many older adults also appear to experience worsenings of any chronic heart or lung conditions, when they experience influenza. These complications of influenza often cause hospitalization or even death.
To learn more about the basics of influenza, and for more on diagnosing and treating the flu, see:
Q: What is the usual impact of influenza, and is it worse for older adults?
Influenza is more severe in some years than others. For instance, the 2017-2018 season was particularly severe, with an estimated 52,000 deaths related to the flu. The 2018-2019 season wasn’t as bad, but still had a real impact: the CDC estimates that there were 29 million flu illnesses that year, causing an estimated 28,000 flu deaths. For 2019-2020, the CDC estimates that there were 35 million flu-related illnesses and 20,000 flu deaths.
Now, most people get better without needing hospitalization, but some people get very sick. Older adults are especially likely to get dangerously ill from catching the flu.
Note: The information above is from pre-COVID times. In the winter of 2020-2021, influenza cases were much much lower than usual, probably due to masking and social distancing associated with the coronavirus pandemic. The flu season for 2021-2022 was also relatively mild, with an estimated 9 million flu-related illnesses and an estimated 5,000 flu deaths.
However, for 2022-2023, flu activity was worse, with the CDC estimating 27-54 million flu-related illnesses and 19,000-58,000 flu deaths.
In comparison, as of July 2023, over 25,000 Americans have died of COVID since the beginning of 2023. CDC data (see slide 14) shows that although last year’s flu season was bad, COVID did cause significantly more hospitalizations.
Q: How does the flu shot help protect one from influenza, and how effective is it?
A: The flu vaccine works by stimulating the body to produce antibodies against whatever strains of influenza were included in that year’s vaccine. After vaccination, it takes about two weeks for the body’s immune system to create its influenza antibodies.
Our bodies are able to fight off viral infections much more quickly if we already have matching antibodies available when a virus tries to create illness in our bodies. If we don’t have matching antibodies available, then we’ll experience more illness, and it will take longer for our immune systems to control the infection.
The tricky thing about influenza is this: both influenza A and B have a tendency to be constantly changing into slightly different strains. This means that every year, scientists must study what influenza strains are present, and try to predict which ones we’ll be exposed to, during the coming winter. Influenza vaccines are then developed, to match those strains. (This is why the flu shot has to be given every year.)
Sometimes the scientific prediction works out well. In this case, we say that the vaccine was well-matched to the influenza viruses circulating that winter, and influenza vaccination will have been more effective in preventing the flu.
But there are years in which the influenza strains that circulate the most in the winter are not the ones that scientists were expecting. These are the years in which the influenza vaccine is not well-matched, and there tends to be more illnesses and hospitalizations.
The CDC estimates that when the vaccine is well-matched to the circulating influenza viruses, flu vaccination reduces the risk of flu illness by between 40% and 60%, for the overall population.
Several different flu vaccines are available every year. Some vaccines used to be “trivalent”; these protected against two strains of influenza A and one strain of influenza B. “Quadrivalent” flu vaccines, available since 2012, protect against two types of influenza A and two strains of influenza B.
For 2023-2024, all flu vaccines are quadrivalent.
Vaccines also vary in terms of whether they are “standard-dose” versus “high-dose,” and one type includes an “adjuvant,” which is an additive designed to increase the immune system’s response to the vaccine. (More response is better, in that it means more protection from future infection.) I’ll discuss high-dose and adjuvant vaccines later in this article, in the section addressing flu shots for aging adults.
You can find a list of all available influenza vaccines in the Table listed below.
For more information:
- Key Facts About Seasonal Flu Vaccine (CDC)
- Vaccine Effectiveness – How Well Does the Flu Vaccine Work? (CDC)
- Understanding How Vaccines Work (CDC)
- Influenza vaccines — United States, 2023-2024 influenza season
Q: Can you get the flu from the flu shot? What are the risks and side effects of influenza vaccination?
A: No, you can’t get the flu from a flu shot. Most of the currently recommended vaccines are made with “inactivated” virus (which means the virus has been killed and can’t become alive again). There is also one vaccine available that was made using “recombinant” technology (which means they have cobbled together virus proteins). It is not possible for these vaccines to give you influenza.
There is also a “live attenuated” form of flu shot (FluMist), available for people ages 2-49, which is given by nasal spray. This contains a weakened form of influenza virus. It has historically been popular with children.
The most common side-effect of the flu shot is arm soreness, and sometimes redness. People do sometimes report body aches, fever, or cough after the flu shot. But a randomized trial found that these are equally common in people who had just had saline injected, so these symptoms are either due to getting sick from something else after your flu shot, or perhaps to even expecting to feel lousy after your flu shot.
Serious adverse effects related to the flu shot are very rare.
For more information:
Q: What are the best ways to protect oneself from influenza and its complications?
A: To reduce your risk of getting sick from the flu or a flu-like illness, it’s best to combine two approaches:
- Minimize your exposure to people spreading the influenza virus in the winter.
- Take steps to bolster your immune system, so that if you do get exposed to the influenza virus, you’ll be less likely to get very sick.
Older adults should also make sure they are up-to-date on pneumococcal vaccination. (These are one-time, not yearly). Pneumococcal vaccination helps reduce the risk of certain types of bacterial pneumonia and other potential complications of influenza. A 2016 meta-analysis concluded that being vaccinated for both influenza and pneumococcus was associated with a lower risk of pneumonia and death.
For a very long time, the pneumococcal vaccine recommended for all adults aged 65+ was the pneumococcal polysaccharide vaccine (“PPSV23”), brand name Pneumovax. However, in 2021, the CDC updated its pneumococcal vaccination recommendations for older adults, in part to incorporate the use of some of the newer pneumococcus vaccines.
You can see the latest pneumococcal vaccination recommendations here: CDC Pneumococcal Vaccination. For more on pneumococcal vaccination, also see 26 Preventive Services for Older Adults (Vaccination section).
Pneumococcal vaccines can be administered at the same time as the annual influenza vaccination.
Minimizing your exposure to influenza virus
The main way people get exposed to influenza is when they breathe in air droplets containing the influenza virus. These droplets are created when people infected with influenza virus talk, sneeze, or cough. The CDC estimates that a person infected with the influenza virus may be contagious for one day prior to developing symptoms, and 5-7 days after getting sick.
Influenza virus can also survive for up to two days. The virus survives for much less time on soft surfaces, such as used tissues and bed linens.
Based on these facts, the best ways to minimize exposure to influenza are to:
- Avoid exposure to people who may be infected with influenza.
- Clean household surfaces, especially hard surfaces such as counters, and especially if someone living with you has been sick.
- Wash your hands often, especially before touching your eyes, nose, or mouth.
- Minimize your time near people who have not been vaccinated for influenza.
- Your risk of influenza exposure is reduced if people around you — family members, co-workers, fellow residents of your living facility — are vaccinated for influenza.
COVID precautions, such as wearing an N95-type mask indoors and ventilating indoor spaces will also help minimize your exposure to influenza.
Bolstering your immune system
Since we are social creatures and live in communities, we all have a good chance of being exposed to the influenza virus at some point. Whether we get sick from this exposure, and how sick we get, depends on how well our immune system can fight off the influenza virus.
Ways to bolster your immune system are:
- Be vaccinated against seasonal influenza. If the vaccine is a good match with circulating viruses and you have a good antibody response, this is probably the best way to prepare your immune system to beat influenza.
- Take good care of your health and body. This includes addressing healthy lifestyle basics such as not smoking, getting adequate sleep, avoiding chronic stress, and more. For a good review of what’s known about strengthening the immune system, see: How to boost your immune system (Harvard Health Review)
What we know about COVID-19 and influenza (and RSV)
Q: How are COVID-19 and influenza similar, and how are they different?
A: COVID-19 and influenza have many similarities, but also many differences. (You should also know that RSV symptoms also have many similarities with flu and COVID; learn more in this article: Respiratory Syncytial Virus: What to Know About RSV & RSV Vaccines in Aging.)
The main similarities between COVID and influenza are:
- Both viruses are mostly spread through an airborne route. This means that steps you take to protect yourself from COVID-19, such as social distancing measures and avoiding crowded indoor spaces, will likely reduce your risk of catching influenza as well.
- The initial symptoms of infection have a lot in common. Namely, both often start with “upper respiratory symptoms” such as cough, runny nose, fatigue, fever, and body aches. This means it will be difficult to tell the two conditions apart, unless laboratory testing is used.
- Both are more likely to cause severe illness in people who are older or frail.
Even though both viruses often cause viral pneumonia, there are significant differences between the two. They are actually quite different types of viruses. The differences include:
- People appear to be infectious for longer, with COVID-19.
- In “mild” COVID-19 (meaning hospitalization is not required), people seem to be sick for longer than with the flu.
- The antivirals known to be active against influenza (such as oseltamivir) do not work against COVID-19.
- Similarly, antivirals that work against COVID, such as Paxlovid, do not work against influenza.
- COVID-19 has been noted to cause more severe and more varied illness in the body than influenza, including clotting disorders, inflammation of organs other than the lungs, persisting long-term symptoms in some patients, and more.
- Although COVID-19 and flu viruses spread in similar ways, COVID-19 seems to be more contagious under certain circumstances.
- Although the mortality rate for COVID-19 is still being debated (we still don’t know exactly how many people have had COVID-19), in adults of all ages, it appears to be higher than that of influenza.
In short, influenza and COVID-19 are similar in terms of how they spread and common initial symptoms. But COVID-19 has so far caused more serious disease, and at this time, remains harder to treat, in part because it seems to affect the body in more significant ways than influenza usually does.
For more on the similarities and differences between influenza, COVID-19, and RSV:
- CDC: Similarities and Differences between Flu and COVID-19
- CDC: Protect yourself from COVID-19, Flu, and RSV
- Respiratory Syncytial Virus: What to Know About RSV & RSV Vaccines in Aging
Q: Is it possible to get influenza and COVID-19 at the same time? How do they affect each other?
A: Yes, over the few years, some people have been found to be co-infected with influenza and COVID-19 at the same time.
That said, our understanding of how these two viruses interact remains limited, as we haven’t yet had large numbers of people be co-infected. For instance, a Mayo Clinic study published in 2022 found only 120 co-infection cases (out of almost 200,000 COVID cases).
Since the arrival of COVID, the past two influenza seasons have been relatively mild in the US. It remains to be seen whether we’ll have a more significant influenza season for 2022-2023 (some experts think we will) and whether this results in a lot of co-infections.
What to know about flu shots for older adults
Q: Is the flu vaccine effective for older adults?
A: You may have heard people say that the flu shot doesn’t work in older people. This is not entirely correct.
Now, it’s true that flu vaccine is usually less effective in older adults because aging immune systems tend to not respond as vigorously to the vaccine. In other words, older adults tend to create fewer antibodies in response to vaccination. So if they are later exposed to flu virus, they have a higher chance of falling ill, compared to younger adults.
But “less effective” doesn’t mean “not at all effective.” For the 2017-2018 flu season, the CDC estimates that vaccination prevented about 700,000 influenza cases and 65,000 hospitalizations, for adults aged 65 and older.
For more on the effectiveness of influenza vaccination in older adults, see:
- Vaccine Effectiveness – How Well Does the Flu Vaccine Work? (You can jump to the section “How effective is the flu vaccine in the elderly?” by using the “On this Page” menu, to the right.)
- Influenza Vaccine Effectiveness in Older Adults Compared with Younger Adults Over Five Seasons
To provide more effective vaccination to aging immune systems, vaccine makers have developed “stronger” vaccines against the flu, which I explain in the next section.
Q: Are there flu shots specifically designed for older adults?
Yes! Over the past several years, vaccine makers have developed vaccines that are designed to work better with an aging immune system. Most research studies to date show that these stimulate aging immune systems to produce more antibodies to influenza. There’s also some evidence that these vaccines reduce the risk of being hospitalized for influenza.
In 2022, for the very first time, the CDC’s Advisory Committee on Immunization Practices (ACIP) decided to recommend certain influenza vaccines specifically for older adults. You can read about this exciting development here: ACIP Flu Meeting Update: Flu Vaccines Worked Better than Reported & ACIP Recommends Specific Vaccines For Seniors.
For 2023-2024, there are three influenza vaccines that are specifically recommended for people aged 65 and older:
- Fluzone High-Dose Quadrivalent: This vaccine contains four times the amount of antigen, compared to Fluzone standard-dose. It is approved for adults age 65+. Fluzone High-Dose has been trivalent in past years but is now quadrivalent.
- Studies have found that the high-dose vaccine does improve antibody response. A study published in 2017 also found that use of the high-dose vaccine in nursing-homes was associated with a lower risk of hospitalization during flu season.
- Fluad Quadrivalent: This vaccine contains an “adjuvant,” which is an additive meant to stimulate a better immune response to the vaccine. It is a newer vaccine in the U.S., but had been licensed in Canada and several European countries prior to receiving approval here in 2015. The quadrivalent version was licensed by the FDA in February 2020.
- An Italian study found that this vaccine resulted in higher antibody titers, among older adults. Another study published in 2020 found that this vaccine “stimulated a superior antibody profile.”
- An industry-funded systematic review & meta-analysis published in 2021 concluded that the trivalent version of this vaccine was effective in reducing influenza illness among older adults.
- Flublok Quadrivalent: This is a recombinant protein influenza vaccine. It is approved for use in people 18 years and older, and as of 2022, it’s also specifically recommended for older adults.
- Per the CDC announcement, “It is made using different production technology than the inactivated influenza vaccines and contains three times the antigen dose compared with standard-dose inactivated flu vaccines. The higher dose of antigen is intended to give people 65 years and older a better immune response to vaccination, and therefore, better protection against flu.”
For more on why the ACIP decided to recommend these three influenza vaccines for older adults, you can view the ACIP slides from June 2022 here.
Note: The ACIP says there is not yet enough data available to say which of the above three vaccines is better for older adults. Also, if none of these three are available to you, it’s fine to get a standard flu shot for adults.
For more information on flu shots for older adults, see:
- CDC: Flu & People 65 Years and Older
- Fluzone High-Dose Seasonal Influenza Vaccine
- FLUAD Flu Vaccine With Adjuvant
- Flublok Quadrivalent
Q: Does Medicare cover the cost of influenza vaccination?
Yes, yearly influenza vaccination is 100% covered by Medicare, with no deductible or co-pay. So if you get your flu shot from a health provider that accepts Medicare payment, there should be no cost.
Q: Is it more important to get a flu shot or a COVID vaccine/booster?
That said, if you’re reluctant to get both and really want to know which is more likely to make a difference to your risk of being hospitalized this winter…
If for some reason, you haven’t yet gotten vaccinated against COVID: I’d go with COVID vaccination. And if you are older: make sure you get a booster too! COVID is just much more dangerous than influenza.
Also, the mRNA COVID vaccines (Moderna, Pfizer) have proven to be extremely effective at protecting older adults against hospitalization due to COVID, especially if you stay up-to-date on boosters. (See my COVID vaccination article for more.)
Now, if you have been vaccinated against COVID and are wondering if a booster or a flu shot is more likely to help you…well, we don’t really know. Australia saw significant flu in the summer of 2022, so we might finally be in for a bad flu season this winter.
Really: the best is to just get updated protection again both influenza and COVID. (And then take precautions to minimize exposure to respiratory illnesses this winter.)
What’s new and resources for the 2023-2024 flu season
The CDC maintains a page dedicated to the current flu season. There is a section for the public and also a section for providers. This is a good place to get up-to-date information on influenza and influenza vaccination. You can find it here:
- 2023-2024 Flu Season (main page)
- Frequently Asked Flu Questions 2023-2024 Influenza Season (main page for the public)
Note that the CDC’s Flu FAQ page currently includes lots of information about influenza and COVID-19, such as how to tell them apart, why it’s safe to be vaccinated for both at the same time, and more.
The CDC also provides information specific to older adults here:
Which influenza vaccination is best for older adults?
Looking at the list of available flu shots can be overwhelming. In looking at this year’s CDC table of available influenza vaccines, I counted eight options that are available for people aged 65 or older:
- 4 standard-dose quadrivalent inactivated vaccines (Afluria Quadrivalent, Fluarix Quadrivalent, FluLaval Quadrivalent, Fluzone Quadrivalent)
- 1 standard-dose quadrivalent inactivated vaccine manufactured with a newer “cell culture-based” technology (Flucelvax Quadrivalent)
- 1 high-dose quadrivalent inactivated vaccine (Fluzone High-Dose Quadrivalent)
- 1 standard-dose quadrivalent adjuvanted inactivated vaccine (Fluad Quadrivalent)
- 1 quadrivalent recombinant vaccine (Flublok Quadrivalent)
Only Fluzone High-Dose Quadrivalent and Fluad Quadrivalent are restricted to people 65 years or older.
As of 2022, the CDC is now recommending these three influenza vaccines for adults aged 65 and older:
- Fluzone High-Dose Quadrivalent
- Fluad Quadrivalent
- Flublok Quadrivalent
So if you are an older adult, or if you’re trying to arrange a flu shot for an aging relative, which flu vaccine should you try to get?
My take is this: if you have a choice, go for one of the three vaccines listed above.
Why? Because we know that as people get older, their immune systems tend to respond less vigorously to immunization. And because research suggests that the high-dose flu shot generates higher antibody titers and has been associated with better influenza outcomes.
You may have also heard that the New England Journal of Medicine published a study in 2017, about a newer influenza vaccine in older adults. That study, funded by the manufacturer of recombinant influenza vaccines, compared the effectiveness of a recombinant quadrivalent vaccine with a standard-dose quadrivalent inactivated vaccine, in adults aged 50 and older. Confirmed influenza cases were 2.2% in the group receiving recombinant vaccine and 3.2% in the group receiving inactivated vaccine. Hence the probability of influenza-like illness was 30% lower with the recombinant vaccine than with the inactivated vaccine. But again, this study did not compare the recombinant vaccine against a high-dose inactivated vaccine.
- What is most important is to get any type of flu vaccination that is approved for your age.
- Research suggests that older adults are more likely to benefit from an influenza vaccine designed to provide a stronger stimulus to the immune system, such as Fluzone High-Dose, Fluad, or Flublok.
- If you are under age 65, you might get better protection from a vaccine that is recombinant (Flublok) rather than made from an inactivated vaccine.
- Flumist, the nasally administered vaccine, is available only to people age 2-49, and so is not an option for older adults.
What to do if your older parent or relative is unwilling or unable to get vaccinated
Now, what if your older parent won’t, or can’t, get a flu shot?
Some older adults just don’t want to get it. Here are some things you can try:
- Ask them to clarify what their concerns are. It’s important to start by listening, in order to understand what an older person believes about the flu and the flu shot.
- Provide information to dispel myths and misunderstandings. Sometimes all people need is a little of the right kind of information.
- Point out that it can benefit an older person’s family members and neighbors. Getting a flu shot can reduce the risk that we pass the flu on to another person. People are sometimes more willing to take action to protect others than to protect their own health.
- Make sure they know they won’t have to pay for the flu shot. If you get the shot from a provider who takes Medicare, it shouldn’t cost anything.
- Offer to go together to get your flu shots. Sometimes it helps to make it a family outing.
There are also some older adults for whom it’s hard to get a flu shot, such as people who are homebound or have very limited transportation options.
If this is your situation, the main thing to do is encourage flu shots (and COVID vaccination!) for family and others coming to the house. For older adults who don’t get out much, their main source of exposure to influenza and other dangerous viruses will be from those who come to them.
Above all, don’t panic if your older loved one can’t or won’t get a flu shot.
Although I’ve just written a long article encouraging flu vaccination for older adults, the truth is this: most years, the chance of getting very sick or dying from influenza are small. Although some seasons, such as the 2017-2018 season, are unusually severe; most years are less severe. (I fully expect that more respiratory illnesses will be related to COVID-19, so prioritize COVID vaccination and boosters!)
Being vaccinated certainly helps make this chance smaller. But not every older person is interested in doing everything possible to reduce the danger of illness. Vaccination is important from a public health perspective, but most people survive flu season whether or not they’ve been vaccinated.
Personally, I think it’s worth getting vaccinated because there’s a small chance that you’ll avoid the misery of having influenza. And, there’s maybe an even better chance that you’ll help reduce the spread of influenza to people around you.
The downsides of getting a flu shot are small. You’ll have to get to a place where they are offering the flu shot. The needle poke will hurt for a moment. Your arm might be sore for a day or so.
And then that’s it! You’ll have done your small part to protect yourself and others.
So, have you decided where to go to get your flu shot? You can find a place to get one here: VaccineFinder.org.
This article was reviewed and updated in September 2023.
Note: Over the past few years there have been occasional comments from readers complaining that my information on vaccination is inaccurate. I’ve decided to stop approving and responding to these comments. BetterHealthWhileAging.net exists to share what I consider “mainstream geriatrics,” which concurs with the public health recommendations from the CDC. People who disagree with these expert recommendations are free to hold their own opinions and can find other spaces online to post such opinions.