- Why do people need vaccines? What is immunization? What is immunity?
- How can people become immune (protected)?
- Are there different types of vaccines?
- Can people receive multiple vaccinations during one visit to the doctor?
- Are there any dangers to being immunized?
- Can people with severe egg allergies still get an annual influenza vaccination?
- What reactions are likely after an immunization?
- Who should not receive a vaccine?
- What vaccines can women receive while pregnant?
- What are invalid reasons for postponing vaccination?
- Why do people keep getting vaccines if the numbers of cases of the vaccine preventable diseases are at a record low in the United States?
- Is there any financial help for people who have been injured by vaccines?
- Is there anything different that health-care workers need to do compared with non-health-care workers?
- Do people need any additional vaccinations for foreign travel?
- Where can people find additional information on immunizations?
Are there different types of vaccines?
There are two major categories of vaccines.
- The first category of vaccine is made from live viruses that have been "attenuated" or weakened so that they do not cause the disease (Table 2). Usually, any symptoms caused by the vaccine is milder than the natural disease. The attenuated viruses elicit a strong immune response as the virus is very close to the virus that causes the disease.
- The second category of vaccine, inactivated vaccine, is produced by growing the bacterium or virus in culture and then inactivating it (killing it) by using heat or chemicals (Table 3). These vaccines cannot cause the disease, but allow the body to develop immunity. While these vaccines are safer, they do not produce protection as good as that from the live vaccines.
Haemophilus influenza type b
Can people receive multiple vaccinations during one visit to the doctor?
Simultaneous administration (vaccines given at the same visit but not in the same shot) of most commonly used vaccines does not decrease the response to the vaccines or increase the risk for adverse reactions. The simultaneous administration of vaccines was instituted to increase compliance with recommended immunization schedules. If people have to come back many times to get additional shots, there is an increased chance that they will not get all recommended vaccinations. In children, there are now a few combination shots that contain multiple vaccines in a single shot. Most of these are approved for use in adults, except Tdap (a three-vaccine combination) and one containing measles/mumps/rubella (MMR). There is an ongoing controversy in the public media about giving "too many" vaccines at one time to little children. Physicians, however, do not believe that children are at risk from "too many" vaccinations given at one time.