Short term reactogenicity of cellular DTP vaccine in 4-6 year old children in Tehran, Iran

To detcnninc the short-term reacrogenicity of diphtheria-tetanus-whole cell pertussis (DTwP) vaccine administered to preschool children in a number of health centers of Tehran in 2006.

In this prospective cohort study, 337 children aged 4-6 years were injected with DTwP vaccine manufactured by Razi Institute of Iran. Reactogenicity was assessed by the parents for 7 days post vaccination using diary cards. Local (pain, redness and swelling) and systemic (fever, loss of appetite, gasterointestinal symptoms, vomiting and eczema) side effects were recorded daily.

Out of 337 children, 312 (92.6%) reported local reactions and 220 (65.3%) reported systemic reactions. No serious adverse events related to vaccination were reported. Among local reacuons, pain was the most frequent (86.9%), but 11 was mostly mild or moderate. Redness (52.8%) and swelling (41.2%) were the most frequently observed signs in the second day. The systemic reactions observed in children included fever (48.4%), loss of appetite (24%), gastrointestinal symptoms (5 6%), vomiting (8%) and eczema (2.7%). Only 3.6% of children had auxiliary fever above 39 'c. All signs were observed to have reduced or completely disappeared during a week.

Compared with previous reports in Iran, reactogenicity of DTwP of Razi Institute seems to be reduced, but it was still more frequent than the internationally approved cellular vaccine counterparts. Reactogcnicity of the cellular triple vaccine may be related to the vaccine formulation or the bacterial cell fragments used in vaccine production.