Vaccines (also called immunizations) help a baby's body build up defenses against serious diseases. Having your baby fully vaccinated will also help lower your baby's risk for SIDS. Many are given in a series of doses. To be protected, your baby needs each dose at the right time. Many combination vaccines are available. They can help reduce the number of times your baby gets poked with a needle to vaccinate against all of these important diseases. Talk with your child's doctor about the benefits of vaccines and any risks they may have. Also ask what to do if your baby misses a dose. If this happens, your baby will need catch-up vaccines to be fully protected. After vaccines are given, some babies have mild side effects, such as redness and swelling where the shot was given, fever, fussiness, or sleepiness. Talk with the doctor about how to manage these symptoms.