Routine consumption of food introduces new bacteria into the body, and numerous bacteria live in the mouth and nose, exposing the immune system to still more antigens. And, indeed, available scientific data show no adverse effects of simultaneous vaccination with multiple vaccines on the normal childhood immune system. A number of studies, have been conducted, to examine the effects of 3iving various combinations of vaccines simultaneously. In fact, simultaneous administration of any vaccine would not be recommended by Health Canada or its national expert advisory committee until such studies showed the combinations to be both safe and effective. These studies have shown that the recommended vaccines are as effective in combination as they are individually, and that such combinations cause no greater risk for adverse side effects.
Research is currently under way to find ways to combine more antigens in a single vaccine injection.
This will assure all the advantages of the individual vaccines, but require fewer shots. There are two practical factors in favour of giving a child several vaccinations during the same visit. First, we want to immunize children as easily as possible to give them protection during the vulnerable early months of their lives. This generally means giving inactivated vaccines beginning at 2 months and live vaccines at 12 months. Second, if we can give several vaccinations at the same time it will mean fewer office visits for vaccinations, which saves parent both time and money and may be less traumatic for the child.