CHAPTER 12

• Jurisdiction: United States

CHAPTER 12 WHAT ADVERSE EFFECTS HAVE BEEN EXAMINED IN PAST VACCINE DEVELOPMENT PROJECTS?

It is important to understand what has been learned in studies of past vaccine effects. A study compared the measles-mumps-rubella vaccine (MMR+V) paired with the varicella vaccine, as opposed to the measles-mumps-rubella-varicella vaccine (MMRV) and observed children (twelve to twenty-three months old) for seven to ten days following vaccination.¹ The MMRV group experienced twice the risk of fever and subsequent febrile seizure than the MMR+V group. Pre-licensure studies revealed higher rates of fever as well as measles-like rash in the MMRV group, but in licensure stages, it was unknown that this increase was associated with increased risk of febrile seizure. As defined by the Mayo Clinic, a febrile seizure is a "convulsion in a child caused by a spike in body temperature . . . . [T]hey're usually harmless and typically don't indicate a serious health problem."²

An autoimmune response in the person being vaccinated may be triggered by adjuvants—molecules in the vaccine that enhance immunological responses within the body.³ Autoimmune disease results when the body's immune system starts attacking its own healthy tissue. When a vaccine elicits an immune response, there is a risk that this could result in an autoimmune disease. There has been no consistent, causal relationship identified between a vaccine and an autoimmune disease, though isolated cases have indicated potential increased risk. The immunization programs for the H1N1 Swine flu vaccine were halted because of a spike in Guillain-Barré syndrome (GBS) cases among individuals who had been immunized.⁴

Anaphylaxis is another remote but serious event. Vaccination anaphylaxis rate is estimated at 1.31 cases per million vaccine doses.⁵

CDC Warning Requirements for Vaccines

The CDC has posted on its website an exhaustive list of contraindications and precautions that the vaccine maker should communicate to the healthcare providers prior to administration of vaccinations. Standard informed consent documents are sent to the vaccination stations for distribution to persons who seek the vaccine.

Importance of the VAERS Monitoring Data

The FDA manages the Vaccine Adverse Event Reporting System (VAERS), a national vaccine safety monitoring system co-sponsored by the CDC and FDA that was established in 1990. By using the system, the FDA and CDC can collect and analyze adverse events reported by individuals (unsolicited...