From Thanksgiving to New Year’s, holiday togetherness comes with a catch: a spike in the viruses that thrive when we all gather inside.

The latest U.S. wastewater data suggests that COVID, flu, respiratory syncytial virus (RSV), and the norovirus stomach bug are on the rise. In some regions, measles is also making appearances. Here’s how to protect yourself amid all the houseguests, hugs, and handshakes.

“During the holiday season, people tend to celebrate together indoors, which increases the opportunity of getting into contact with people,” says Wan Yang, PhD, assistant professor of epidemiology at the Columbia University Mailman School of Public Health. “Even though some of them may not have symptoms of infection, they could have an infection and unknowingly pass it to loved ones and friends.”

Vaccines can reduce your risk of catching flu, COVID, RSV, and measles — or of developing severe symptoms if you do get sick, says Judd Hultquist, PhD, the Dr. Robert L. Murphy Professor of Emerging Infectious Diseases at Northwestern University’s Feinberg School of Medicine in Chicago. It takes about 10 to 14 days after a shot to build protective antibodies. That means even if you get vaccinated just before Thanksgiving, your strongest protection will be in place for the full stretch of holiday gatherings that follow, Hultquist says.

Make your home comfortable for your family — not their germs. Use humidifiers. Indoor heating can dry the air, creating an environment where viruses linger longer. “Increased humidity helps lower the chance that the virus survives once it’s emitted into the air,” when infected people exhale, cough, or sneeze, says Yang. Aim for 40% to 60% humidity.

Bars, restaurants, and other crowded spaces increase the chance of exposure. Yang’s research during the early pandemic in New York City found that bringing together people from different neighborhoods in close quarters like these contributed to the spread of COVID. Hosting at home or cooking for family can be a safer alternative. If someone is coughing or sneezing, keep some distance. “Even six feet can dramatically lower your chances of catching an infection over the course of a party,” says Hultquist.

Clean your hands frequently, especially after touching shared surfaces. Respiratory viruses can spread via surfaces as well as the air, so sanitizer is a quick way to reduce risk. Viruses can enter through your eyes, nose, or mouth. One playful reminder: a sparkly nail polish design can help you notice when you’re about to touch your face, says Hultquist.