the age group above 15?years, there are 63 participants that have mentioned a positive history of taking part in the campaign of November 2015. the minimum sero-immunity level of a population for achieving elimination is usually calculated based on these values.12,13 For measles, the mentioned minimum inhibitory level of the herd-immunity is about 94.4%; and for rubella, this value comes to 87.5%.8-10 In fact, the herd protection threshold for measles is the highest of all Coluracetam vaccine-preventable diseases and may even vary in different settings.8,12 Based on the results of the present study, the lowest level of immunity was in the same age groups not covered in the mass immunization campaign of November 2015. This difference is additional evidence in favour of the effectiveness of the campaign in TNR enhancing the level of immunity in the target age groups. However, with regard to the seroprevalence rates of the age group 16 to 20?years, it should be kept in mind that in December 2003 these people had been children aged 4 to 8?years, i.e. most of them (those who then had been 5 to 8?years old) should have taken part in the nationwide measles/rubella campaign of the same year. As another point of concern, in the last two columns of Tables 1 and ?and2,2, i.e. the age group above 15?years, there are 63 participants that have mentioned a positive history of taking part in the campaign of November 2015. The mean age of these participants was 17.2?years (SD = 1.0; Median = 16.9 years). These participants were not supposed to take part in the campaign; however, allegedly they have taken part and have received the vaccine. Even though we did not gather the required information which can justify this, our best suggestion is that these people have received the vaccine in their schools during the campaign of November 2015. Still, there were no statistically Coluracetam significant differences between seroprevalence rates of those who allegedly had taken part in the campaign of November 2015 and those who had not, either for measles (P-value = 0.519) or for rubella (P-value = 0.376). Even though, based on the findings presented in Tables 1 and ?and2,2, the level of herd-immunity against rubella is not as high as that for measles, as it was described before, the minimum inhibitory level of herd-immunity is much lower than the level required for measles (about 87.5%). Therefore, the situation for rubella, even for those parts of the population with sero-immunity below 90%, seems even more reassuring in terms of achieving elimination goals. Before the introduction of rubella vaccine, the incidence of congenital rubella syndrome (CRS) in Iran, like most other countries, varied from 0.1- 0.2/1000 live births during endemic periods, and from 0.8 C 4/1000 live births during rubella epidemics.14,15 This is while based on the latest reports of the rubella surveillance system, during 2016, the incidence of rubella (not congenital rubella syndrome) in Iran has been about 0.32 per million total population.5 Based on the findings of the present study, it Coluracetam might be speculated that within the next few years, the frequency of measles outbreaks in the study area will decrease substantially. Before the mass immunization campaign of November 2015, these areas were the most problematic regions with regard to measles elimination efforts. The immunity level of the study population with regard to rubella is reassuring and favourable too. No doubt, in order to achieve the elimination goals, in addition to efforts undertaken for keeping a high immunization coverage as well as routine surveillance and well-organized sero-surveys, campaigns of supplementary vaccination play a substantial role. Materials and methods The survey was implemented from July 24th to August 26th, 2016, about eight months after the vaccination campaign of November 2015 mentioned above. The provinces involved included parts of Sistan-va-Baluchestan and Hormozgan provinces as well as the southern regions of Kerman Province. Even though the vaccination campaign of 2015 did not include the age group above 15?years in this survey, the age group of 16 to 20?years was also included and blood sampled. In Iran, provision of.