Safety of revaccination with pneumococcal polysaccharide vaccine

Context Revaccination of healthy adults with pneumococcal polysaccharide va ccine (PPV) within several years of first vaccination has been associated w ith a higher than expected frequency and severity of local injection site r eactions. The risk of adverse events associated with revaccination of elder ly and chronically ill persons 5 or more years after first vaccination, as is currently recommended, has not been well defined. Objective To determine whether revaccination with PPV at least 5 years afte r first Vaccination is associated with more frequent or more serious advers e events than those following first vaccination. Design Comparative intervention study conducted between April 1996 and Augu st 1997. Participants Persons aged 50 to 74 years either who had never been Vaccinat ed with PPV (n = 901) or who had been vaccinated once at least 5 years prio r to enrollment (n=513). Intervention PPV vaccination. Main Outcome Measures Postvaccination local injection site reactions and pr evaccination concentrations of type-specific antibodies. Results Those who were revaccinated were more likely than those who receive d their first vaccinations to report a local injection site reaction of at least 10.2 cm (4 in) in diameter within 2 days of vaccination: 11 % (55/513 ) vs 3% (29/901) (relative risk [RR], 3.3; 95% confidence interval [CI], 2. 1-5.1). These reactions resolved by a median of 3 days following vaccinatio n. The highest rate was among revaccinated patients who were immunocompeten t and did not have chronic illness: 15% (33/228) compared with 3% (10/337) among comparable patients receiving their first vaccinations (RR, 4.9; 95% CI, 2.4-9.7), The risk of these local reactions was significantly correlate d with prevaccination geometric mean antibody concentrations. Conclusions Physicians and patients should be aware that self-limited local injection site reactions occur more frequently following revaccination com pared with first vaccination; however, this risk does not represent a contr aindication to revaccination with PPV for recommended groups.