a preliminary study to evaluate the immune response to a booster dose of the adult tetanus-diphtheria vaccine (td) available in iran

Background: despite the availability of tetanus-diphtheria (td) vaccines in iran, the seroconversion rate of these products as a booster dose is unknown. objectives: this study evaluates the seroconversion rate of the iranian td vaccine in adults who have not been vaccinated in the past decade. methods: in this study, 20 adult volunteers aged 18 to 60 who had not received the td vaccine in the past decade received a booster dose of the iranian td vaccine. twenty-eight days after vaccination, the seroconversion rate was evaluated using the elisa method. vaccine adverse events were monitored at three time points after vaccination. results: seroconversion rates with the iranian td vaccine boosters were 75% and 90%, respectively, based on a 4-fold increase in anti-tetanus toxoid antibody titers and a 2- and 4-fold combination. significant associations were found between the demographic data, specifically female gender and age 43 years and older, with seroconversion rates. injection-site pain was the most common adverse reaction, with a frequency of 35%. no adverse events were reported between one week and one month after vaccination. conclusions: results showed that a booster dose of the iranian td vaccine produced a protective titer (> 0.1 iu/ml) and a long-term protective titer (> 1.0 iu/ml) in 100% of participants. the seroconversion rate of the iranian td vaccine was comparable to other common tetanus vaccines, including tenivac ®, adacel ®, infanrix ®, tetavax ®, and vacteta ®. the proportion of suitable candidates for plasma donation, based on minimum (2 iu/ml) and maximum (10 iu/ml) anti-tetanus toxoid antibody titers, was 100% and 45%, respectively.