This is for informational purposes only. For medical advice or diagnosis, consult a professional.
The 2026 flu vaccine recommendations are refreshingly simple: nearly everyone 6 months and older should get a flu shot every season, and adults 65 and older do best with a stronger version. Polio protection matters too, though most adults are already covered from childhood.
If you have been putting off the shot, or worrying that it is not worth the trouble, you are not alone. This guide walks through what the science actually says, answers the questions Pasadena readers ask most, and gives you a calm next step for each one.
Which Vaccines Matter Most This Flu Season?
Polio is different. Most adults were fully vaccinated as children and do not need anything more. Only a small group of adults ever needs a one-time polio booster, which the sections below explain.
Here is who this season’s shots are for:
- Flu: everyone 6 months and older, every year, with rare medical exceptions.
- Flu for adults 65 and older: a higher-dose or adjuvanted version is preferred.
- Polio: routine for children; for adults, only those who are unvaccinated or at higher risk of exposure.
How a Flu Vaccine Works
The seasonal flu vaccine for 2026-2027 protects against three influenza viruses. You need a fresh one each year for two reasons: protection fades over months, and the viruses themselves keep changing.
Does the Flu Vaccine Really Work, and Is It Worth It?
The CDC points to a 2021 study in which flu vaccination was linked to a 26 percent lower risk of being admitted to intensive care and a 31 percent lower risk of dying from flu among adults, compared with people who were not vaccinated. Vaccination also reduces doctor visits and missed work.
Effectiveness does vary from year to year, depending on how well the vaccine matches the circulating viruses and on your own age and health. Even in a season with a weaker match, the shot can still prevent illness from the other viruses it covers, which is why the recommendation holds every year. The National Foundation for Infectious Diseases notes that even when a flu vaccine does not fully prevent infection, it can still guard against the serious complications that lead to hospital stays.
Can the Flu Shot Give You the Flu?
The viruses in a flu shot are either killed (inactivated) or not whole viruses at all, so there is nothing there that can infect you. The nasal spray uses a weakened virus that cannot reproduce in the warm parts of your lungs where flu takes hold.
Some people do feel a little achy or run a low fever for a day after the shot. That is the immune system doing its job as it builds protection, and it passes quickly. It is a much smaller thing than a real bout of flu.
What Side Effects Should I Expect?
The usual reactions to a flu shot include:
- Soreness, redness, or swelling where the shot was given
- Headache
- A low fever
- Muscle aches
- Nausea or tiredness
Fainting can occasionally follow any injection, so it helps to sit for a few minutes afterward. Serious reactions are very rare.
Still, it is smart to know the warning signs. A severe allergic reaction is uncommon but can begin within minutes to a few hours, with trouble breathing, swelling of the face, lips, or throat, hives, a racing heartbeat, or dizziness. If any of these appear, call 911. Anyone who has had a severe reaction to a flu vaccine in the past should talk with a provider before the next one, as noted on the CDC page on who should not get a flu shot.
Why Do Adults 65 and Older Need a High-Dose or Adjuvanted Flu Shot?
The stakes are higher in this age group. The CDC reports that in recent years an estimated 70 to 85 percent of flu-related deaths and 50 to 70 percent of flu-related hospitalizations have occurred in people 65 and older.
If you are in this group and feel unsure about the stronger shot, a few points may reassure you. It is not experimental; it has been the preferred choice for older adults for several seasons. Studies suggest it is potentially more effective than a standard-dose shot for this age group. And if a preferred version is not in stock the day you visit, a standard-dose flu vaccine is a fine substitute, so there is no reason to leave without one. The nasal spray, though, is not recommended for people 65 and older.
This is also a natural moment to ask about pneumococcal protection. The CDC recommends that people 50 and older stay up to date on pneumococcal vaccination, which can often be given at the same visit as your flu shot.
Why Would an Adult Need a Polio Booster?
A one-time lifetime booster is meant only for adults who were fully vaccinated as children but now face a higher chance of exposure. The CDC lists the situations that count as higher risk:
- Traveling to a country with a documented increased risk of poliovirus
- Working in a lab or healthcare setting that handles specimens which might contain poliovirus
- Being a healthcare worker or caregiver in close contact with someone who could be infected
- Being identified by public health authorities as part of a group at risk during an outbreak
There is a separate situation. Adults who were never vaccinated, or who are not sure they finished the series, should complete it. The full adult series is three doses, and the inactivated polio vaccine has been the only type used in the United States since 2000.
The protection is worth the small effort. The CDC notes that two doses provide at least 90 percent protection and three doses at least 99 percent. Side effects are usually limited to a sore spot where the shot was given.
Where and When Can Pasadena Residents Get Vaccinated?
Flu shots are widely available. You can get one at a doctor’s office, a pharmacy, a health department, or an urgent care or walk-in clinic. If you are weighing your options, this overview of what a walk-in clinic can and cannot handle is a helpful starting point, and several Exer Urgent Care locations in Pasadena offer vaccinations as well.
A primary care visit is often the easiest place to sort out which flu shot fits you and whether your polio history is complete. Local groups such as Physicians of Southern California handle this kind of routine care, and Pasadena family physician Cleo Tsolakoglou-Williams, M.D., can review your records and talk through your questions in plain language.
For an older adult who finds leaving the house hard, there is a gentler option: a doctor who makes home visits can bring a flu shot and a simple checkup to the door. That can be a relief for a homebound parent who still wants to stay protected.
One more piece of calm guidance. If you are 65 or older and come down with flu symptoms, call your provider promptly, because early antiviral treatment is recommended for this group. And for anyone, warning signs such as trouble breathing, chest pain, confusion, or bluish lips call for emergency care right away. If you are choosing an over-the-counter product to ride out a cold, this guide to safer cough remedies for seniors and people with high blood pressure can help you read the label with confidence.
Frequently Asked Questions
Can I get a flu vaccine and another vaccine at the same visit?
In general, yes. A flu vaccine can usually be given at the same visit as other recommended vaccines, such as a pneumococcal or polio dose, often in different arms. Your provider can confirm what is right for you and your health history.
I have an egg allergy. Can I still get a flu vaccine?
Yes. People with an egg allergy can get any flu vaccine that is otherwise appropriate for their age and health. Since the 2023-2024 season, no extra precautions beyond those used for any vaccine are needed, regardless of how severe a past egg reaction was.
Is the nasal spray flu vaccine an option for me?
The nasal spray is an option for many healthy people ages 2 through 49 who are not pregnant. It is not recommended during pregnancy, for people with a weakened immune system, or for adults 65 and older. If you are unsure, ask your provider which form suits you.
When is it too late in the season to get a flu shot?
It is rarely too late. Early fall is the ideal time, but a shot in the winter still offers protection as long as flu viruses are circulating. Keep in mind it takes about two weeks for the vaccine to take full effect.
How do I know whether I was fully vaccinated against polio as a child?
Most adults raised in the United States were vaccinated in childhood. You can check old immunization records, ask the provider who cared for you as a child, or look into your state’s immunization registry. Your current provider can help decide whether you need any doses.
Should I also ask about a pneumococcal vaccine?
If you are 50 or older, the CDC recommends staying up to date on pneumococcal vaccination, and it can often be given at the same visit as your flu shot. Your provider can tell you which pneumococcal vaccine is recommended for you.
