VISs were not intended to substitute for provider knowledge or for parent-provider communication, but rather to make such communication easier, according to a physician who coordinated the development of the VISs. Studies show that some knowledge is gained from reading VISs in an ideal setting, in which the research interviewer minds the child and the parent reads at his or her leisure. "However, even under these optimal circumstances, immediate and long-term recall is far from impressive," she said. One study showed that only 54 percent of parents coming to a clinic with an infant or toddler knew that there were two types of polio vaccine, a statement that appears in a large, bold heading on the front of the polio VIS (Humiston et al., 1996).
The target audience for VISs is a diverse group with a wide range of interests and abilities. The statements have been criticized by some as having too high a reading level. The statement about the polio vaccine, for example, requires a reading level beyond the capability of 57 percent of an inner-city Philadelphia clinic population (Melman, et al., 1995). In contrast, some criticize the VISs for not providing enough information. For parents who wish to know more than is provided in a VIS, a notation on each states, "If you want to learn more, ask your doctor or nurse. She/he can give you the vaccine package insert or suggest other sources of information."
The primary tool for communicating the risks and benefits of a vaccine to health care providers is the manufacturer's vaccine package insert. This insert includes statements on efficacy, contraindications, warnings, precautions, and adverse events associated with use of the vaccine. The information in the package insert comes from clinical trials conducted with the vaccine, postmarketing studies, spontaneous adverse events reported to the manufacturer, and adverse events reported to VAERS and in relevant medical journals. Package inserts are regulated by the FDA, which determines the type of information that must be included and reviews and approves each package insert prior to marketing and whenever changes are made. Factual statements in a package insert must be supported by data from clinical studies and references to scientific literature.
The contraindications section of the insert discusses situations or conditions, such as known or suspected severe egg allergy, for which a vaccine should not be used because the risks apparently outweigh the benefits. The warnings section describes serious adverse events and potential safety hazards, as well as limitations in the use of the product and steps that should be taken if these limitations occur.