Clinical use of Biken acellular DPT in two-month old infants

We have examined the antibody titer and side effects in two-month-old infants (1.5-2.5) who received vaccinations of acellular DPT Combined Vaccine Adsorbed "Biken" Lots 22 and 23. We observed high-antibody titers far in excess of prevention levels. No particular increase in side effects was observed in the two-month-old infants, except a normal increase in once-only side effects. The results suggest that this vaccine can protect infants under one year of age, who are especially liable to be affected by this illness.