How do vaccines work?
Vaccines are oral or injected preparations made up of dead or weakened disease organisms (bacteria or viruses). When living disease organisms enter a person's system, the body fights infection by producing antibodies which attack and kill the organisms. In a similar fashion, vaccines stimulate the production of antibodies, but without causing the serious symptoms which occur during infection with living disease organisms. The result is that the body develops immunity to that particular disease, and is protected for several months or for a lifetime, depending on the vaccine.
Some vaccines induce prolonged or even lifelong immunity to certain diseases, and can be given just once. But others, such as pertussis or diphtheria, only induce a temporary immunity. These vaccines require repeat injections (called boosters) in order to maintain protection against such diseases.
Are vaccines safe?
Generally, vaccines are safe and very effective. The benefits of immunization far outweigh any risks. Typical side-effects may include a mild fever or slight rash, depending on the vaccine. Your child's physician may recommend acetaminophen to treat mild fever. More serious side effects are rare, but if other symptoms develop or fever is high, consult your child's physician.
Keeping an immunization record
It's a good idea to keep a record of immunizations received. Record sheets are often provided by doctors or clinics. They're valuable if your family moves or changes doctors, and are a handy reminder of upcoming vaccines or boosters. They are also proof of your child's protection against certain infectious diseases - proof which you may need to enrol your child in school or to travel overseas.
Your child's immunization record should specify the types of vaccine, and be dated and signed by the doctor each time an immunization is given. The record should be kept at home in a safe, accessible place, and should be taken with the family on trips away from home.