Harrison C. Stetler

Monitoring system for adverse events following immunization.

The Monitoring System for Adverse Events Following Immunization (MSAEFI) has collected data from the public sector nationwide on adverse events occurring during the 4-week period following administration of vaccine. From 1979 to 1984, 6483 reports were received. Although rates of reporting have increased throughout the 6-year period, increases were larger for less serious events (209%) than for more serious events (53%). The MSAEFI data have been used to evaluate risk factors for adverse events following immunization, will continue to provide information on the safety of both current and future vaccines and may identify other factors that increase the risks of adverse events following immunization.

History of convulsions and use of pertussis vaccine

Data on 2062 reports from the Monitoring System for Adverse Events Following Immunization, Centers for Disease Control (CDC), were analyzed to compare the risk of a personal or family history of convulsions in children who had a neurologic adverse event after receipt of diphtheria-tetanus-pertussis (DTP) vaccine with those who had a nonneurologic adverse event. Children with a neurologic event after DTP vaccine had a 7.2 times higher risk for personal history of convulsions (95% confidence limits 4.5 to 11.5) and a 4.5 times higher risk for family history of convulsions (95% confidence limits 3.1 to 6.7) than did children with an adverse event that did not affect the nervous system. Children with either a febrile or nonfebrile convulsion after receipt of DTP were significantly more likely to have a personal history of convulsions than children with a nonneurologic adverse event (P less than 0.0001). Children with a febrile convulsion after receipt of DTP but not children with nonfebrile convulsions were significantly more likely to have a family history of convulsions than those with a nonneurologic adverse event. It is recommended that pertussis vaccination be deferred in children with a personal history of a convulsion until it can be determined that an evolving neurologic disorder is not present. If such disorders are found, these children should be given the combined pediatric diphtheria and tetanus toxoids (DT) vaccine to complete the series.

Streptococcal abscesses following diphtheria-tetanus toxoid-pertussis vaccination.

Abscesses developed in seven children who received diphtheria-tetanus toxoid-pertussis vaccine at a clinic in Indiana. Epidemiologic investigation revealed that all seven children had received vaccine from the same multidose vial and had been vaccinated by the same nurse at the office of one physician. Group A beta-hemolytic Streptococcus was isolated from abscesses in six of the seven children. No source was identified as the cause of this cluster of abscesses. Vaccine of the same lot number used elsewhere was not associated with the development of abscesses. It appears that the vaccine became contaminated during use.

Fetal Risk Associated with Rubella Vaccine

Ninety-four susceptible women received either Cendehill or HPV-77 rubella vaccine. All gave birth to healthy infants. Seventeen susceptible women received the RA 27/3 vaccine. All their infants were free of abnormalities compatible with congenital rubella, as were 54 born to mothers of unknown immune status at the time of RA 27/3 vaccination and those later found to be immune. An additional susceptible woman received an unknown strain of vaccine; she also had a healthy infant. The risk of severe congenital malformations after rubella vaccination is low. In our 112 cases, the maximum risk was approximately 3%. Concern about the potential adverse effects of rubella vaccine on the fetus should not interfere with vaccination of women of childbearing age. However, since the actual risk may not be zero, women known to be pregnant should not be vaccinated, and conception should be avoided for three months after vaccination.