title: Influenza B virus reinfection.
abstract: Four outbreaks of influenza B infection occurred in Houston, Texas in the years 1976-1984. In the Houston Family Study, age-related infection and illness rates in the recent two epidemics resembled those reported previously. A total of 118 persons, including 35 children followed from birth, were followed longitudinally through this entire period and 331 persons were studied through at least two outbreaks. Fifty-nine (88%) of 67 children studied for four outbreaks were infected and 25% had a second infection; about half of the adults had one infection but only one of 51 was reinfected. Infection rates were proportionally lower for those followed through 2-3 outbreaks. Those with documented infection were protected decreasingly over time against reinfection and associated illness in subsequent epidemics. Such protection decreased in efficacy from 65% after 2-3 years, to 46% after 4-5 years, and to no protection after seven years.
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D004196:Disease Outbreaks; D006801:Humans; D007223:Infant; D009981:Influenza B virus / Q000302:isolation & purification*; D007251:Influenza, Human / Q000453:epidemiology* / Q000276:immunology; D008137:Longitudinal Studies; D012008:Recurrence; D012621:Seasons; D013781:Texas