There is an Outbreak of Disease While it is preferable to observe the recommended time interval between shots, sometimes an outbreak of disease requires an accelerated schedule of shots. The trade off to this is that the level of immunity may not be as good as when the recommended schedule is followed. However, during these times of outbreak, it is preferable to have some immunity than no immunity. The normal schedule for this immunization is a shot at 2,4,6, and 15 months. During this outbreak, children in these cities were recommended to have the pertussis vaccine at 1,2,3, and 12 months.
Some children have illnesses which require a medication called immune globulin.
Certain immunizations don't work well if given shortly after immune globulin has been given, therefore, these immunizations are delayed usually for 3 months after the last dose. The official recommendations allow for some flexibility of when shots may be given. This difference has been driven primarily by the individual state's laws. Different Companies Make Different Vaccines There has been a recent explosion in the varieties if vaccines. The Hepatitis B comes alone or combined with the Hib.