REACTIONS FOLLOWING ADMINISTRATION OF INFLUENZA VACCINE ALONE OR WITHPNEUMOCOCCAL VACCINE TO THE ELDERLY

Background: Even though the efficacy of pneumococcal vaccine against i nvasive pneumococcal infections and other closely related infections h as been established, its use in the United States is only one quarter of that of influenza vaccine. The simultaneous administration of the t wo vaccines could be expected to raise the coverage of pneumococcal va ccination to a considerable degree. There is a paucity of data regardi ng the reactions associated with the simultaneous administration of pn eumococcal and influenza vaccines. Methods: All persons aged 65 years or older living in 29 administrative districts in Northern Finland wer e offered influenza vaccine alone or influenza and pneumococcal vaccin es. A total of 9336 persons (49.6% of the target population) accepted vaccination: 4581 persons born in odd years received influenza vaccine , and 4755 persons born in even years received influenza and pneumococ cal vaccines. Local reactions were recorded in a diary by vaccinees on the day of vaccination and for 4 days afterward according to the foll owing scale: no reaction, mild reaction, strong reaction, and disablin g reaction. The participants who felt feverish were asked to measure a nd record their temperature. Ninety-three percent of those vaccinated returned the diary. Results: No serious reactions were observed. The i ncidence of local reactions was 284 per 1000 vaccinations in the influ enza-vaccinated group and 441 per 1000 vaccinations in the influenza-p neumococcal-vaccinated group, a difference of 157 (95% confidence inte rval, 137 to 176), and that of fever (temperature, at least 37.5 degre es C) was 10 and 24 per 1000, respectively, for a difference of 14 (95 % confidence interval, 9 to 19). The frequency of local reactions decr eased with advancing age. Conclusion: Because the adverse reactions to the pneumococcal and influenza vaccines when given together were mild , we conclude that the simultaneous administration of the two vaccines to the elderly population, irrespective of age, is safe.