Benefit of Inactivated Influenza Vaccine in Infants in Iran: A Community based Randomized Control Trial

Influenza in infants and young children is a major medical problem which causes excess medical visits, antibiotic prescriptions and hospitalization even in otherwise healthy children. Many of the developed countries have recommended influenza vaccination for all children (>6month old), but the economic benefit of this strategy is not clear especially for developing countries.

To find the difference in the incidence of influenza-like illness (ILI) and economic cost related to it between TIV vaccinated and non-vaccinated infants in Mashhad, Iran.

This was a community randomized controlled trial which was started in November 2005 and ended up at May 2006. Each of the study and control groups were composed of 500 infants between 6 month and 20 months old who were brought for routine vaccination. The study group was given two doses of TIV; the control group received routine care without any extra intervention. Both groups were followed by monthly telephone calls (up to six months after the vaccination) and were asked about signs and symptoms of flu like illnesses and any cost related to them. SPSS 11.5 was used for statistical analysis, P<0.05 is considered as statistically significant.

There was no significant difference in the monthly occurrence of ILI between the vaccinated and non-vaccinated groups (P: 0.06- 0.97). The costs related to ILI were similar between vaccine and control groups, except for physicians visit cost in the third month, which was more in the control group (P<0.05).

In influenza season of 2005-06, TIV vaccination did not decrease the rate of influenza-like illnesses and was not cost saving in infants (6- 20 months old) in Mashhad.