No abstract

Pertussis in adolescents and adults is common, endemic, and epidemic worldwide, and its incidence is reportedly increasing. Although a number of individuals suffer only a mild cough, many others have symptoms typical of pertussis, causing prolonged cough illness, frequent use of health care resources, missed work and a variety of complications. Symptoms experienced by adolescents and adults include sleep disturbance, weight loss, pharyngeal discomfort, influenza-like symptoms, sneezing attacks, hoarseness, sinus pain, headaches and sweating attacks. Even when symptoms are typical of pertussis, the diagnosis is often not considered in adolescents and adults because of a low awareness of the disease in these age groups. Contrary to common perceptions, complications of pertussis, including some that are serious, are not infrequent in adolescents and adults. These include urinary incontinence, rib fracture, pneumothorax, inguinal hernia, aspiration, pneumonia, seizures and otitis media. Despite underreporting, hospitalization of adults and adolescents does occur. Many believe that adolescents and adults are the groups most commonly infected with pertussis and are now the major source of contagion to infants and young children. Because of the considerable health burden, there is a need for improved vaccination strategies to prevent disease in adolescents and adults and to reduce the risk of transmission to vulnerable infants.

In 2- to 10-year-old children MCV-4 had a safety profile similar to that of PSV-4 and elicited significantly higher and more persistent serum bactericidal antibody responses against meningococcal serogroups A, C, Y and W-135 than did the licensed polysaccharide vaccine.

Rotavirus vaccine development is a high priority. The association between the tetravalent rhesus-human reassortant rotavirus vaccine and intussusception has increased the need to develop new vaccines. In a small efficacy trial, the human rotavirus vaccine 89-12 recently has been shown to be safe and effective; 184 of the 215 healthy infants initially enrolled in this trial were followed for a second year. Vaccine efficacy during the second year was 59% (P=.047). For the 2 years of observation, vaccine efficacy was 76% against rotavirus gastroenteritis, 83% against severe rotavirus gastroenteritis, and 100% against rotavirus illnesses requiring medical intervention (P<.001 for each). These encouraging results have led to continued evaluation, in several countries, of a vaccine candidate derived from strain 89-12.