Getting a flu vaccine each year is the single most effective way to avoid the flu, reducing your risk of infection by roughly 40 to 60 percent depending on the season and your age. But vaccination works best as part of a layered approach. The habits you keep during flu season, from how you wash your hands to the humidity in your home, all influence whether you get sick.
Get Vaccinated Every Year
The flu vaccine remains your strongest line of defense. In the 2024–2025 season, preliminary CDC data showed vaccine effectiveness ranging from about 42 to 56 percent for adults across different monitoring networks. For children, the numbers were even better: vaccination reduced the risk of flu-related hospitalization by as much as 78 percent. Even in years when the vaccine is a less-than-perfect match for circulating strains, it consistently lowers the odds of severe illness, hospitalization, and death.
Your body needs about two weeks after the shot to build full antibody protection, so the best time to get vaccinated is in September or October, before flu activity peaks. Protection does wane over the course of months, which is one reason a new shot is recommended every year rather than relying on last season’s immunity.
For the upcoming 2025–2026 season, all flu vaccines will be trivalent, meaning they protect against three virus strains: an H1N1 strain, an H3N2 strain, and a B/Victoria lineage strain. You don’t need to choose between options or worry about which version you receive. Any age-appropriate flu vaccine counts.
Know If You’re at Higher Risk
Some people face a much greater chance of serious complications if they catch the flu. Adults 65 and older and children under 2 are at the highest risk. Infants younger than 6 months old have the highest rates of hospitalization and death, and they’re too young to be vaccinated, so protecting them depends entirely on the people around them getting their shots.
Chronic health conditions also raise the stakes. Asthma, diabetes, heart disease, kidney disease, liver disorders, COPD, sickle cell disease, and conditions that weaken the immune system (like HIV or cancer treatment) all increase the likelihood that a flu infection turns dangerous. The same is true for people with a BMI of 40 or higher, people who have had a stroke, and those with neurological conditions that affect breathing or swallowing. Pregnant women, including those up to two weeks postpartum, are also in this group.
If any of this applies to you or someone in your household, the everyday prevention steps below matter even more.
Wash Your Hands the Right Way
The flu virus spreads easily through contaminated hands. You touch a doorknob, a shopping cart, or someone else’s phone, then touch your face, and the virus has a direct route to your nose, mouth, or eyes. Washing with soap and water for at least 20 seconds is the most reliable way to remove it.
When you can’t get to a sink, hand sanitizer with at least 60 percent alcohol is an effective backup. Sanitizers in the 60 to 95 percent alcohol range are significantly better at killing germs than lower-concentration or alcohol-free versions. Keep a small bottle in your bag, your car, or your desk during flu season so you actually use it.
Understand How the Virus Spreads
Flu primarily travels through respiratory droplets released when an infected person coughs, sneezes, or talks. But surface contact is a real transmission route too. Influenza A and B viruses survive 24 to 48 hours on hard, nonporous surfaces like stainless steel, plastic, and countertops. On softer materials like cloth, paper, and tissues, they survive less than 8 to 12 hours.
This means high-touch surfaces in your home and workplace, think light switches, faucet handles, keyboards, and phones, can harbor live virus for up to two days. Wiping these down regularly during flu season is a simple habit that reduces your exposure. If someone in your household is already sick, cleaning shared surfaces at least once a day makes a meaningful difference.
Keep Indoor Air From Getting Too Dry
The flu virus thrives in dry air. Research on humidity and influenza seasonality has consistently found that dry conditions, around 20 to 35 percent relative humidity, favor both viral survival and person-to-person spread. At intermediate humidity levels around 50 percent, the virus becomes notably less stable.
This partly explains why flu season hits hardest in winter, when heated indoor air drops to very low humidity. Running a humidifier to keep your home closer to 40 or 50 percent relative humidity can make your indoor environment less hospitable to the virus. A basic hygrometer (available for a few dollars at most hardware stores) lets you monitor the level. Going above 60 percent creates its own problems, like mold growth, so the 40 to 50 percent range is the sweet spot.
Build Everyday Habits That Help
Wearing a mask in crowded indoor spaces during peak flu season reduces your exposure to respiratory droplets. Both surgical masks and N95 respirators offer protection, and current evidence hasn’t established a clear winner between the two for everyday use. Either is better than nothing when you’re in a packed subway car, airport terminal, or waiting room during a bad flu season.
A few other practical habits add up over time:
- Avoid touching your face. Your eyes, nose, and mouth are the entry points. Keeping your hands away from them, especially in public, cuts off a major transmission route.
- Stay away from visibly sick people. There’s no single “safe” distance, since spread depends on ventilation, how much someone is coughing, and other factors. But putting more space between yourself and someone who’s clearly ill reduces your exposure.
- Get enough sleep. Chronic sleep deprivation weakens your immune response and makes you more susceptible to infection after exposure. Seven to nine hours consistently is the general target for adults.
- Maintain adequate vitamin D levels. Low vitamin D is linked to increased susceptibility to respiratory infections. If you live in a northern climate or spend most of your time indoors, your levels may be low by winter. Blood levels above 40 to 60 ng/mL appear to be protective. A simple blood test can tell you where you stand, and supplementation is inexpensive if you’re deficient.
What to Do When Someone at Home Is Sick
If a family member comes down with the flu, your goal is to limit how much virus reaches the rest of the household. Have the sick person stay in a separate room as much as possible and use a separate bathroom if one is available. Give them their own towels, cups, and utensils.
Clean hard surfaces in shared areas daily, since the virus can survive on them for up to two days. Wash your hands immediately after any contact with the sick person or anything they’ve touched. Open windows briefly when weather allows to improve ventilation, and run a humidifier to keep the air from drying out.
If you’re in a high-risk group and a household member gets the flu, antiviral medication taken within the first 48 hours of your own symptom onset can reduce the severity and duration of illness. Some people at very high risk may be prescribed antivirals preventively after a known exposure, even before symptoms appear.