Influenza is not a bad cold. It comes on quickly with fever, body aches, exhaustion and cough, it can keep healthy adults in bed for days, and in older adults and people with chronic illness it can lead to pneumonia, hospitalization and worsening of heart and lung disease. The yearly flu vaccine is the single most effective way to lower that risk.
The CDC recommends a flu vaccine every season for everyone 6 months and older, with rare exceptions. A new shot is needed each year because flu viruses change and the vaccine is updated to match the strains expected to circulate, and because protection from last year's dose fades.
At New York Medicine Doctors, our internal medicine physicians give flu shots to adult patients at our Midtown Manhattan and Forest Hills offices, often during a visit you already have scheduled. We care for adults only; children should get their flu vaccine through their pediatrician.
Who should get a flu shot, and who especially
Every adult benefits, but vaccination matters most for people at higher risk of complications. The CDC lists adults 65 and older, pregnant women, and people with asthma, COPD and other chronic lung disease, diabetes, heart disease, kidney or liver disease, neurological conditions, and weakened immune systems from illness or medication. It also notes that most people hospitalized with flu have at least one underlying condition.
If you have diabetes, flu can drive blood sugar up and make it harder to control. With asthma or COPD, flu is a common trigger of serious flare-ups. With heart disease, the strain of a flu infection raises the risk of cardiac events. For these patients, the flu shot is part of managing the chronic condition itself. People who live with or care for someone at high risk should be vaccinated too.
When to get vaccinated
The CDC considers September and October the best months, aiming to be vaccinated by the end of October so protection is in place before flu activity rises. Getting vaccinated in July or August is not recommended for most adults, particularly those 65 and older, because protection may wane before the end of the season. If you miss October, it is still worth getting the shot later, since flu often circulates well into spring. It takes about two weeks after vaccination for protection to build.
Which flu vaccine is right for you
Standard flu shot
Most adults under 65 receive a standard-dose inactivated flu vaccine, given as a single injection in the upper arm. Egg-free options, including cell-based and recombinant vaccines, are also available.
Higher-dose and adjuvanted vaccines for 65 and older
The immune response weakens with age, so the CDC preferentially recommends one of three vaccines for adults 65 and older: high-dose inactivated vaccine, recombinant vaccine, or adjuvanted inactivated vaccine, which are potentially more effective than standard-dose vaccines in this age group. If none of these is available, a standard-dose shot is better than waiting. Nasal spray flu vaccine is not recommended for adults 65 and older.
If you have an egg allergy
Egg allergy is no longer a reason to avoid or delay the flu shot. According to the CDC, people with egg allergy may receive any flu vaccine appropriate for their age and health, with no special precautions beyond those used for every vaccination. The people who should not get a flu shot are those who have had a severe allergic reaction to a flu vaccine or one of its ingredients other than egg; if that applies to you, tell us so we can discuss alternatives.
Side effects
The flu shot cannot give you the flu, because it contains no live virus. Common side effects include soreness, redness or bruising where the shot was given, headache, low-grade fever, fatigue, muscle aches and occasionally nausea. The CDC describes these as usually mild and short-lived, typically lasting a day or two. Serious reactions are rare. If you have had Guillain-Barré syndrome within six weeks of a previous flu shot, or if you are moderately or severely ill on the day of your visit, let us know before vaccination.
Getting your flu shot at NYMD Center
We give flu shots to adult patients during office visits in the fall and winter, so you can combine it with a physical, a chronic-disease follow-up or a sick visit once you are feeling better. Before the shot we confirm your age, allergies and any prior vaccine reactions and choose the appropriate vaccine. The injection itself takes a minute. Many patients also use the visit for a vaccination review, since shingles, pneumococcal, RSV and COVID-19 vaccines may also be due, and several can be given at the same visit.
Other ways to protect yourself during flu season
The flu shot works best alongside everyday habits. Wash your hands often, avoid close contact with people who are sick, and stay home when you have a fever so you do not pass the virus to coworkers or family. Covering coughs and sneezes, and wearing a mask in crowded indoor spaces during peak weeks if you are at high risk, add further protection. People who live with or care for infants, older relatives or anyone with a weakened immune system help protect them by getting vaccinated themselves. And because flu and COVID-19 circulate in the same months, fall is a good time to review whether your other respiratory vaccines are current.
If you get sick anyway
No vaccine is perfect, but vaccinated people who catch flu often have a milder illness. If you develop fever, body aches and cough during flu season, call us early: antiviral treatment works best when started within the first couple of days, especially for high-risk adults. See our general illnesses page for sick visits. Call 911 for trouble breathing, chest pain or pressure, confusion, or severe weakness.
Questions patients ask
When is the best time to get a flu shot?
The CDC recommends September or October, ideally by the end of October, so you are protected before flu activity rises. Most adults, especially those 65 and older, should not get vaccinated as early as July or August, because protection can fade before the season ends. If you miss October, getting vaccinated later in the season is still worthwhile.
Can I get the flu shot if I am allergic to eggs?
Yes. The CDC says people with egg allergy may receive any flu vaccine that is otherwise appropriate for their age and health, with no extra precautions beyond the standard ones used for all vaccinations. Egg-free vaccines are also available. The people who should not receive a flu shot are those with a prior severe allergic reaction to a flu vaccine or its non-egg ingredients.
Which flu shot is best for people 65 and older?
The CDC preferentially recommends a high-dose, recombinant or adjuvanted flu vaccine for adults 65 and older, because these are potentially more effective than standard-dose vaccines in this age group. No one of the three is preferred over the others. If none is available, a standard-dose flu shot is better than going without. Nasal spray vaccine is not recommended at this age.
Can the flu shot give me the flu?
No. Flu shots contain inactivated virus or a single viral protein, not live virus, so they cannot cause influenza. Some people feel tired, achy or slightly feverish for a day or two, which is the immune system responding. Catching a cold around the same time, or being exposed to flu before protection builds over about two weeks, can make it seem otherwise.
Why do I need a flu shot every year?
Flu viruses change from year to year, and the vaccine is updated each season to match the strains expected to circulate. Protection from a flu shot also declines over the months after vaccination. A yearly shot keeps your protection current. This is especially important if you are 65 or older or have diabetes, heart disease, asthma or COPD.