Illness after influenza vaccination reported through a nationwide surveillance system, 1976-1977.

In 1976, the Center for Disease Control coordinated nationwide surveillance for illnesses after influenza vaccination as part of an effort to vaccinate the nation against influenza A/New Jersey/76. For the 48,161,019 persons vaccinated in 1976, a total of 4733 reports of illness were received which included reports of 223 deaths. When Guillain-Barré syndrome was reported in vaccine recipients, an investigation was begun to examine this possible association. Other than the Guillain-Barré syndrome and rare cases of anaphylaxis, no serious illnesses were causally associated with influenza vaccination by this type of surveillance. Widespread underreporting of illness and death in the passive phase of this surveillance system, however, impaired the ability to draw conclusions about reactions to vaccine from the reports of illness received.

Guillain-Barre syndrome following vaccination in the National Influenza Immunization Program, United States, 1976--1977.

Because of an increase in the number of reports of Guillian-Barre syndrome (GBS) following A/New Jersey influenza vaccination, the National Influenza Immunization Program was suspended December 16, 1976 and nationwide surveillance for GBS was begun. This surveillance uncovered a total of 1098 patients with onset of GBS from October 1, 1976, to January 31, 1977, from all 50 states, District of Columbia, and Puerto Rico. A total of 532 patients had recently received an A/New Jersey influenza vaccination prior to their onset of GBS (vaccinated cases), and 15 patients received a vaccination after their onset of GBS. Five hundred forty-three patients had not been recently vaccinated with A/New Jersey influenza vaccine and the vaccination status for 8 was unknown. Epidemiologic evidence indicated that many cases of GBS were related to vaccination. When compared to the unvaccinated population, the vaccinated population had a significantly elevated attack rate in every adult age group. The estimated attributable risk of vaccine-related GBS in the adult population was just under one case per 100,000 vaccinations. The period of increased risk was concentrated primarily within the 5-week period after vaccination, although it lasted for approximately 9 or 10 weeks.

The epidemiology of influenza B in a rural setting in 1977.

An epidemic of influenza B began in January, 1977, in two rural parishes in northeastern Louisiana and quickly spread to involve 29% of their population with clinical influenza. This epidemic was investigated using a standard questionnaire and a random sample of 4.2% of the population. The clinical illness was typical of influenza, with predominant fever, cough, malaise and headache. Gastrointestinal symptoms were part of the clinical syndrome. Rhinitis and diarrhea were significantly more common in children aged five years or less. Clinical attack rates increased with larger household size. The youngest age groups had clinical attack rate of 40--55%, but the elderly had very low attack rates. The direct cost of influenza-like illness during the epidemic averaged almost $30.00 per case. Knowledge of the cost of influenza-like illness and age-specific attack rates should be useful in planning future control efforts for influenza B.

Excess mortality and influenza surveillance in Taiwan.

Excess mortality has proven to be a useful epidemiologic tool for influenza surveillance in the temperate zone. A retrospective analysis of the epidemiology of influenza in Taiwan was undertaken to explore the usefulness of this technique in the tropical--subtropical zone. Excess mortality similar to that observed during influenza epidemics in the temperate zone was noted during periods of previously recognized influenza epidemics in Taiwan. For the very young and the elderly excess mortality was observed to be even higher than in the temperate zone. Virus isolations, increased school absenteeism, and high clinical attack rates were also noted during influenza epidemics. Use of these epidemiologic techniques in Taiwan proved to be a useful approach to describe the impact of influenza.

Studies of inactivated influenza virus vaccines in hospital employees: reactogenicity and absenteeism.

The impact of a mass influenza vaccination program on the operation of a major medical center was evaluated in adult volunteer employees who were given either ether-split or whole-virus bivalent influenza vaccine in a double-blind manner by jet-injector gun. Each volunteer completed a reaction information form, nurses monitored temperatures, and data on absenteeism of the employees of the Nursing Service and the Building Management Service were collected. The results of this study demonstrated that the mass campaign did not adversely affect absenteeism. However, the whole-virus vaccine caused significantly more local, systemic, and febrile reactions thant the split-virus vaccine. Purified inactivated influenza virus vaccines can be given in a mass campaign to hospital personnel without adversely affecting the operation of the hospital.