What is a vaccine? Vaccines are a treatment to prevent infections. They teach the body to resist the causative organisms that cause infections. Thanks to vaccines, the number of people who die from infections has dropped significantly, especially in children. Vaccines have also reduced the number of people suffering from polio and other infectious diseases that can cause permanent disability. Most vaccines are administered by intradermal injection, but some are also inhaled through the nose or swallowed by mouth. Some vaccines require only one dose, while others require two or more doses. Usually the vaccine starts to work a few weeks after the vaccination. Why do I need to get vaccinated? Vaccinations can prevent disease, and even if you get sick, they can prevent you from getting sicker. In addition, vaccinations can protect people around you from getting sick. What are the side effects of vaccines? Generally speaking, vaccines do not have side effects. If side effects do occur, they can be as follows: redness, mild swelling or pain at the vaccination site; mild fever; mild rash; headache or general discomfort; sometimes the vaccine can cause serious side effects, such as a severe allergic reaction. But they are relatively rare. When should I get vaccinated? What vaccines should I get? Different vaccines are needed at different times in a person’s life: Infants and children need all the vaccines against infections that may occur during their lifetime. These include: anti-measles vaccine, anti-mumps vaccine, anti-rubella vaccine, and anti-polio vaccine. Children over 6 months of age and adults need an annual flu vaccination. Some adults also need the most common pneumonia vaccine. In addition, adults sometimes need vaccinations that they never received as children. Vaccinations against local infectious diseases are required when traveling. Can vaccinations cause autism? No. After extensive and rigorous clinical trials, scientists have not found a link between vaccines and autism. Although one study many years ago found a link between autism and vaccination, that study was later proven to be wrong and has been withdrawn. What if I am allergic to eggs? Please consult your doctor and ask which vaccine is safe for you. Some vaccines are made from eggs, so people with severe egg allergies sometimes react less well to these vaccines. However, people with mild allergies can usually receive vaccines made from eggs. Also, there are vaccines that are not made from eggs and can be used for certain people.