IMMUNOGENICITY AND TOLERABILITY OF A TRIVALENT INFLUENZA SUBUNIT VACCINE (INFLUVAC(R)) IN HIGH-RISK CHILDREN AGED 6 MONTHS TO 4 YEARS

Fifty-two children, aged less than 5 years, with chronic lung disease or congenital heart disease were entered into a two-centre open study to determine the immunogenicity and tolerability of Influvac(R), a tri valent influenza sub-unit vaccine. Seroresponses were determined follo wing two intramuscular vaccinations with 0.25 mi of Influvac, four wee ks apart. Any local or systemic reaction was sought. Seroresponses wer e age and antigen specific, with children older than 9 months showing better seroresponses to all three antigens. Both A/Taiwan and B/Panama strains met all efficacy criteria. A/Shangdong met two of the three c riteria: seroconversion and mean geometric titre increase. Local (23%) and systemic (48%) reactions following either of the two vaccinations were minor in nature and resolved within a few days. The vaccine indu ced a strong antibody response against all three haemagglutinin antige ns and was well tolerated. The incidence of local and systemic reactio ns was comparable with those reported in healthy adults.