Influenza vaccines in children. Comparison of new cetrimonium bromide and standard ether-treated vaccines.

We compared a new cetrimonium bromide (CTAB) subunit vaccine with a conventional polysorbate (Tween)-ether split-product vaccine in 63 children and young adults. The vaccines each contained influenza A/Bangkok/79, A/Brazil/78, B/Singapore/79; two doses were given one month apart. Among persons initially seronegative for A/Bangkok/79, the geometric mean antibody titer rose to more than 100 following one dose of vaccine, while those initially seropositive had titers of greater than 200 after one dose of either vaccine. Neither vaccine was able to induce comparable antibody titers to A/Brazil/78 or B/Singapore/79 after one dose in initially seronegative persons. After two doses the titers were greater than 100 for A/Brazil but not for B/Singapore. An A/Bangkok epidemic struck the New York City metropolitan area. The attack rate in the unvaccinated matched sibling control group was 35% (15/43). Only two of the 27 recipients of cetrimonium bromide vaccine and none of the 36 polysorbate-ether vaccines had a fourfold or greater increase in antibody titer during the epidemic.