There are several things you can do to help boost your immune system and keep it functioning at its best:

1. Eat a balanced diet: A diet rich in fruits, vegetables, whole grains, and lean meats to support immune function.
2. Stay hydrated: Drinking enough water.
3. Exercise regularly: Regular physical activity can help flush bacteria out of your lungs and airways, which can reduce your chances of getting sick.
4. Get enough sleep: Sleep is important for overall health and can help support the immune system. Aim for at least 7-9 hours of sleep each night.
5. Minimize stress: Chronic stress can suppress the immune system, so it is important to find ways to manage stress, such as through exercise, meditation, or therapy.
6. Avoid smoking and limit alcohol consumption: Smoking and excessive alcohol consumption can damage the immune system, so it's important to avoid these habits or limit your consumption.
7. Get vaccinated: Vaccines can help protect you against certain diseases by priming the immune system to recognize and fight the pathogens that cause these diseases.

It's important to keep in mind that there is no single food or supplement that can provide a guaranteed boost to the immune system. The best way to support your immune system is to adopt a healthy lifestyle that includes a balanced diet, regular exercise, adequate sleep, stress management, and avoiding habits that can harm the immune system.