Measles is still one of the most common infectious killers of children in the world, especially in developing countries. In Iran, during the prevaccine era, 150,000-500,000 cases of measles were reported annually, with a death rate of 10%-15%. After the establishment of Expanded Program on Immunization program in 1984, vaccination rates for the first and second doses of measles vaccine increased to >90% by the mid-1990s, and the number of measles cases decreased to 2652 in 1996. In response to increased numbers of cases in older age groups during 1996-2002, a nationwide measles-rubella vaccination campaign was conducted in 2003, and 33,100,000 persons (99%) aged 5-25 years were vaccinated. During 2004-2009, 221 laboratory-confirmed measles cases (<1 case per million population) were detected, primarily in rural areas and among migrant groups who traveled to or came from high-incidence countries. High routine immunization coverage, low disease incidence, and surveillance system data suggest that interruption of endemic virus transmission might have already been achieved in Iran, but challenges remain and continued efforts are needed to sustain this accomplishment.

Implementation of a comprehensive strategy for measles elimination in Iran has remarkably reduced the incidence of measles and rubella to <1 case per 1,000,000. Sporadic transmission continues to occur, particularly in areas with immigrant and nomadic populations.

Pertussis caused by Bordetella pertussis, remains a public health problem worldwide, despite high vaccine coverage in infants and children in many countries. Iran has been using whole cell vaccine for the last 50 years with more than 95% vaccination rate since 1988 and has experienced pertussis resurgence in recent years. Here, we sequenced 55 B. pertussis isolates mostly collected from three provinces with the highest number of pertussis cases in Iran, including Tehran, Mazandaran, and Eastern-Azarbayjan from the period of 2008-2016. Most isolates carried ptxP3/prn2 alleles (42/55, 76%), the same genotype as isolates circulating in acellular vaccine-administrating countries. The second most frequent genotype was ptxP3/prn9 (8/55, 14%). Only three isolates (5%) were ptxP1. Phylogenetic analysis showed that Iranian ptxP3 isolates can be divided into eight clades (Clades 1-8) with no temporal association. Most of the isolates from Tehran grouped together as one distinctive clade (Clade 8) with six unique single nucleotide polymorphisms (SNPs). In addition, the prn9 isolates were grouped together as Clade 5 with 12 clade-supporting SNPs. No pertactin deficient isolates were found among the 55 Iranian isolates. Our findings suggest that there is an ongoing adaptation and evolution of B. pertussis regardless of the types of vaccine used.

ObjectivesDuring recent decades, there has been limited attention on the seasonal pattern of pertussis within a high vaccine coverage population. This study aimed to compare the seasonal patterns of clinical suspected pertussis cases with those of laboratory confirmed cases in Iran.MethodsThe current study was conducted using time series methods. Time variables included months and seasons during 2011–2013. The effects of seasons and months on the incidence of pertussis were estimated using analysis of variance or Kruskal–Wallis.ResultsThe maximum average incidence of clinically confirmed pertussis was 23.3 in July (p = 0.04), but the maximum incidence of clinical suspected pertussis was 115.7 in May (p = 0.6). The maximum seasonal incidences of confirmed and clinical pertussis cases were reported in summer (average: 12, p = 0.004), and winter (average: 108.1; p = 0.4), respectively.ConclusionThe present study showed that the seasonal pattern of laboratory confirmed pertussis cases is highly definite and different from the pattern of clinical suspected cases.

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To determine the prevalence of vaccine-associated paralytic poliomyelitis (VAPP) in immunodeficient infants, we reviewed all documented cases caused by immunodeficiency-associated vaccine-derived polioviruses in Iran from 1995 through 2008. Changing to an inactivated polio vaccine vaccination schedule and introduction of screening of neonates for immunodeficiencies could reduce the risk for VAPP infection.

Polio might not be eradicated unless long-term vaccination with inactivated poliovirus vaccine is implemented.

BackgroundThe most important factors that affect the incidence of vaccine-related complications are the constituent biological components of the vaccine, injection site reactions, age and sex. The aim of this study is to determine the incidence rate of adverse events following immunization with pentavalent vaccine (DTPw-Hep B-Hib (PRP-T) vaccine (pentavac) (adsorbed) is manufactured by Serum Institute of India ltd), which was introduced in Iran in November 2014. It is important to monitor vaccine-related adverse events because of the role of vaccine safety in immunization program success.MethodsThis study was a mixed cohort study that included 1119 children less than 1 year of age. In 2015, the children were referred to Hamadan health centers to receive pentavalent vaccine at 2, 4 and 6 months of age. The data were collected from the parents of the children using a questionnaire that was administered either face-to-face or by telephone. The cumulative incidence of side effects and risk ratio was reported with 95% confidence intervals (CI). Chi-squared tests and logistic regressions were used to investigate the association between the variables.ResultsThe cumulative incidence rate of pentavalent-related adverse events during 48 h following immunization was estimated to be 15.8% for swelling, 10.9% for redness, 44.2% for pain, 12.6% for mild fever, 0.1% for high fever, 20.0% for drowsiness, 15.0% for loss of appetite, 32.9% for irritability, 4.6% for vomiting and 5.5% for persistent crying. There is no evidence for the occurrence of convulsion and encephalopathy among children who receive pentavalent vaccines.ConclusionFurther large studies with long time follow up are required to address rare events include convulsions, encephalopathy or persistent crying. However, Findings urge immunization programs to use pentavalent vaccinations and to continue implementing the current immunization program in children under 1 year of age.