Fall is in full swing, meaning colorful foliage, delicious pumpkin treats, and—perhaps best of all—cooler weather.

It’s important to remember that cooler weather can also mean greater risk of getting sick. Scientists have proven that cooler temperatures weaken our immune system, making us more susceptible to illness and infection.

Additionally, cooler weather toughens the outer shell of viruses, making it easier for them to travel from person to person.

Here’s a list of four vaccines that Medicare helps pay for and that you should talk with your doctor about to help protect yourself from illness this winter and beyond.

1. Influenza Vaccine The flu—or influenza—is a contagious respiratory illness that can be severe and life-threatening. Older adults–even if they are healthy– are at higher risk when it comes to the flu due to age-related weakening of our immune systems, making it more difficult for us to fight off disease. Flu combined with pneumonia– a common acute condition among the aging population– is one of the top 10 causes of death for those aged 65+ in the U.S. According to the CDC, the flu vaccination is the best way to prevent the flu.

2. Shingles Vaccine Shingles is a painful skin rash that’s caused by the same virus responsible for chickenpox. Shingles is less contagious than chickenpox, and can only be passed on to another person up until the point when the infected person’s blisters begin to scab. Even after shingles passes, long-term pain can linger. One in three adults contracts shingles at some point in their life– the majority of whom are 60 years or older– and the older you are when you get shingles, the more likely seniors are to have severe side effects, like fever, exhaustion and loss of appetite.

3. Pneumococcal Vaccine Pneumococcal disease causes severe infections throughout the bloodstream and/or key organs. While seniors may not have heard of pneumococcal disease, they have probably heard of the conditions that result from this disease, including pneumonia (infection of the lungs), meningitis (infection of the lining of the brain and spinal cord), and bacteremia (infection of the bloodstream). Pneumococcal disease can result in deafness, brain damage, loss of limbs, and even death.

4. Hepatitis B Vaccine Hepatitis B is a contagious virus that infects the liver. Acute hep B, which usually lasts a few weeks, often mimics symptoms similar to the flu, like fever and nausea. Chronic hep B is long-term, often has no symptoms at all, and can cause liver damage or death. The liver and its function change as people age, making hepatitis B more prevalent among older adults.

Getting these vaccines is an important part of healthy aging, and they also help ensure the health of friends and family.

Seniors should see their doctor and then check with your Medicare provider about where you can get them.