Is there any way I can boost my immune system?

Some ideas. Keep your weight in its recommended range for your height, gender, and age. Get plenty of rest and exercise. Lighten up—try to laugh more & stress less. Make sure your vitamin D level is within the normal range. Eat more foods containing omega-3 fatty acids. Don't smoke. Drink alcoholic beverages moderately. Get all recommended vaccinations. That oughta do it.
Be healthy. Eat well, exercise and get plenty of sleep. Eat a well balanced diet with plenty of fruits and veggies. Be safe - wash your hands, cover your mouth, etc... Get all recommended vaccines! nothing else is clinically proven with great studies to tremendously change immune function.