Wash hands often and avoid touching your eyes, nose or mouth. Germs typically enter the body via the hands. Get enough sleep. Adequate rest is essential for a well-functioning immune system. Reduce stress. Too much can hinder the immune system. Eat a balanced diet. Dietitian Gabrielle Tuscher suggests including 'lots of fresh fruits and vegetables, lean proteins such as lean chicken breast, seafood, bean curd, tuna, salmon, low-fat dairy products and unrefined wholegrain products such as breads, cereals and brown rice'. Get moving. Health agencies recommend 20-30 minutes of physical activity every day.