Regular checkup examinations and vaccines are important for two reasons. One is that, during regular check up examinations, you can see for yourself whether you have become ill with a transmittable disease that could affect the people in your environment. This helps you take preventive measures that will combat the possible disease. Another reason is that with vaccinations, you contribute to herd immunity of your nearby group, as the higher the herd immnunity (percentage of people who are vaccinated), the lower the probability that a certain disease will be transmitted throughout your social network.