Most infections spread through a handful of predictable routes: your hands touch a contaminated surface and then your face, you breathe in particles from a sick person nearby, you eat undercooked food, or bacteria enter through a break in your skin. Blocking those routes with simple, consistent habits is the most effective way to stay healthy. Here’s how to do it across every major category of risk.
Hand Hygiene
Your hands are the single most common vehicle for spreading germs to your eyes, nose, and mouth. Washing with soap and water for 40 to 60 seconds reduces bacteria on the skin by roughly 92%. Alcohol-based hand sanitizer works slightly better at about 94% reduction and takes less time, around 20 to 30 seconds. Using both methods together, washing first and then applying sanitizer, achieved 100% bacterial reduction in a controlled trial comparing the two.
Soap and water is the better choice when your hands are visibly dirty, greasy, or have been exposed to certain pathogens like norovirus, which alcohol doesn’t kill as reliably. Sanitizer is a strong backup when you’re away from a sink. The key detail most people miss is time: a quick five-second rinse under the tap does almost nothing. You need to scrub all surfaces of your hands, including between fingers and under nails, for the full 40 to 60 seconds to get meaningful germ removal.
The highest-impact moments to wash are after using the bathroom, before eating or preparing food, after blowing your nose or coughing, and after touching shared surfaces like door handles, shopping carts, or public transit rails.
Respiratory Protection
Respiratory infections spread through particles expelled when a sick person coughs, sneezes, talks, or even breathes. The World Health Organization now describes these as “infectious respiratory particles” on a continuous spectrum of sizes, rather than drawing a hard line between large droplets and small aerosols. This matters because it means transmission can happen at both short and long distances depending on airflow, humidity, and ventilation.
When protection is needed, the type of mask you choose makes a significant difference. A surgical mask is loose-fitting and blocks splashes and large particles, but its edges don’t seal around your face, so very small particles can slip in around the sides. An N95 respirator, by contrast, is designed to form a tight seal around your nose and mouth and filters airborne particles far more efficiently. N95s don’t work properly on children or people with facial hair because the seal can’t form correctly.
Ventilation is equally important. The National Institute for Occupational Safety and Health recommends aiming for at least five air changes per hour in indoor spaces to meaningfully reduce viral particles in the air. A Lancet Commission report grades four air changes per hour as “good,” six as “better,” and anything above six as “best.” You can improve air exchange at home by opening windows on opposite sides of a room, running exhaust fans, or using a portable air purifier with a HEPA filter. These equivalent air changes count toward the same goal.
Staying Current on Vaccines
Vaccines train your immune system to recognize and fight specific pathogens before you’re exposed. For adults, the CDC’s current schedule includes several infections worth staying on top of:
- Influenza: one dose annually, with a higher-dose version preferred for adults 65 and older
- COVID-19: one or more doses of the current season’s updated vaccine for adults 19 to 64, and two or more doses for those 65 and older
- RSV: recommended for adults 75 and older, with shared decision-making for those 60 to 74
- Tetanus, diphtheria, and pertussis (Tdap/Td): one Tdap dose, then a booster every 10 years
- Hepatitis A: two to four doses depending on the specific vaccine, if not previously vaccinated
- Pneumococcal disease: recommended for older adults and those with certain health conditions
Pregnant individuals have additional recommendations, including a Tdap dose during each pregnancy and seasonal RSV vaccination to pass protection to the newborn.
Food Safety
Foodborne illness is one of the most preventable types of infection, and it comes down to temperature. Bacteria like Salmonella, E. coli, and Listeria are killed when food reaches specific internal temperatures. A food thermometer is the only reliable way to confirm doneness, since color and texture are misleading.
The USDA’s minimum safe internal temperatures are:
- Poultry (whole birds, breasts, thighs, wings, ground): 165°F (73.9°C)
- Ground beef, pork, veal, and lamb: 160°F (71.1°C)
- Steaks, chops, and roasts (beef, pork, veal, lamb): 145°F (62.8°C), then rest for at least 3 minutes
- Fish and shellfish: 145°F (62.8°C)
- Eggs: 160°F (71.1°C)
- Leftovers and casseroles: 165°F (73.9°C) when reheating
Beyond cooking temperatures, keep raw meat separate from ready-to-eat foods, refrigerate perishables within two hours (one hour if the temperature outside is above 90°F), and wash cutting boards and utensils with hot soapy water after they contact raw meat or eggs.
Wound Care
Any break in the skin, from a paper cut to a scrape from a fall, creates a direct entry point for bacteria. Proper cleaning in the first few minutes dramatically lowers the chance of wound infection.
The best cleansing agent is simply normal saline or clean tap water. Saline is preferred because it’s isotonic, meaning it matches your body’s salt concentration and won’t damage healing tissue. If you don’t have saline, potable tap water works well. Boiled and cooled water or distilled water are alternatives if tap water quality is uncertain. Gently irrigate the wound to flush out dirt and debris rather than scrubbing aggressively, which can push contaminants deeper into the tissue.
One counterintuitive finding: pouring antiseptics like hydrogen peroxide or rubbing alcohol directly into a wound can actually harm your body’s natural defenses and increase infection risk. These agents reduce bacteria on intact skin effectively, but inside a wound they damage the cells responsible for healing. U.S. guidelines for treating pressure ulcers specifically discourage antiseptics and recommend saline only. If you want to disinfect, apply the antiseptic to the skin surrounding the wound while keeping it out of the wound itself. Once clean, cover the wound with a sterile bandage to keep new bacteria out and maintain a moist healing environment.
Supporting Your Immune System
Your immune system is the last line of defense when prevention measures fall short. While no supplement replaces good hygiene or vaccination, vitamin D has the strongest evidence for reducing respiratory infection risk, particularly in children and adolescents. The Endocrine Society suggests daily vitamin D supplementation for children ages 1 to 18, noting it may lower the risk of respiratory tract infections. Clinical trials showing benefit used doses averaging around 1,200 IU per day.
For adults, maintaining adequate vitamin D levels matters most for people who get limited sun exposure, have darker skin, or live in northern latitudes. Beyond supplementation, the fundamentals of immune health are well established: consistent sleep of seven or more hours per night, regular moderate exercise, a diet rich in fruits and vegetables, limited alcohol intake, and effective stress management. None of these are dramatic interventions on their own, but together they keep your body’s defenses functioning at baseline rather than compromised.
Surface Cleaning
High-touch surfaces like light switches, doorknobs, phone screens, and countertops can harbor pathogens for hours to days. The EPA maintains a list of disinfectants proven effective against viruses including SARS-CoV-2, and the critical detail is contact time. A disinfectant only works if the surface stays visibly wet for the full duration listed on the product label, which can range from 30 seconds to 10 minutes depending on the product. A quick spray-and-wipe usually isn’t enough.
For everyday household cleaning, focus on the surfaces that get touched most often. Phones deserve special attention since most people touch their phone dozens of times per hour and then touch their face. Wiping your phone with a disinfectant-compatible wipe once or twice a day, especially after being in public spaces, is a simple habit with outsized impact.