Acute adverse events following immunization with DTP-HB-Hib pentavalent vaccine in the first year of life

Background: Since November 2014, the pentavalent (Diptheria+Tetanus+Pertussis and Hepatitis B and Hib or DTP-HBHib) vaccine has been integrated into the Iranian national vaccination programme. Aims: We conducted a prospective study in Zahedan in the southeast of the Islamic Republic of Iran to determine the incidence of adverse events following immunization (AEFI) with the pentavalent vaccine in children aged under one year. Methods: Using cluster sampling, 1119 children aged 2–10 months at 15 public health clinics were invited, through their parents, to participate in the study. The parents were trained to register and report any AEFIs in a questionnaire. They were instructed to return the child to the clinic for further examination by a physician if they observed any complications within 3 days of vaccination. Results: The most commonly reported AEFIs were fever (50.94%), mild (41.46%) and severe (1.70%) injection site complications, persistent crying for 3 hours or more (1.88%), hypotonic hyporesponsive episode (0.36%), vomiting (1.88%), diarrhoea (2.95%), and sterile abscess (0.62%). There were no cases of convulsion, purulent abscess or rash. The work experience of vaccinators (OR = 1.85; 95% CI: 1.4–2.46) showed a significant statistical association with the incidence of mild local complications at the injection site. Those with a history of Bacillus Calmette–Guérin (BCG) lymphadenitis (OR = 3.89; 95% CI:1.04–14.49) had a higher risk of severe local complications at the injection site. Conclusions: The observed incidence of serious AEFIs following pentavalent vaccine injection in the study population was within the expected range. However, some of the relationships observed in this study require further research.

Immunization coverage of children aged 24–35 months in the Islamic Republic of Iran: a national cluster coverage survey

Background: Although vaccination coverage against a disease is not exactly the same as community immunity against that disease, it is undoubtedly directly related to it and provides an estimate of the coherence and efficacy of community health infrastructure. Aims: To evaluate the vaccination coverage of children throughout the Islamic Republic of Iran in 2019. Methods: This was a cross-sectional study. A probability proportional to size cluster sampling method was used and the vaccination data of 8682 children aged 24–35 months were collected in the form of 1447 clusters, each comprising six participants. Only valid data, including vaccination card or electronic health files, were used. The results were reported in the form of descriptive tables. Results: Overall, 97.82% of Iranian participants (8068 of 8248) and 90.32% of non-Iranian participants (392 of 434) had received all essential childhood vaccination by the time of interview. In total, 93.02% of all participants had presentable vaccination cards, and the immunization history of 535 (6.16%) children was retrieved using their electronic health files. The dropout rate between receiving pentavalent vaccine 1 and pentavalent vaccine 3 was 0.01%. In 29 provinces, vaccination coverage was ≥ 95%. In the other two provinces, the figure was 93.30%.Conclusion: Immunization coverage of children aged 24–35 months fully complied with eradication/elimination goals of vaccine-preventable diseases. In 2019, measles and rubella elimination was certified in the Islamic Republic of Iran. However, non-Iranian residents with immunization coverage < 95% constitute a high-risk group for possible outbreaks.

Effect of Leishmania gerbilli injection on mice immunization against cutaneous leishmaniasis (CL) caused by Leishmania major.

In the present study Leishmania gerbilli were used to immunize BALB/c mice against pathogenic strains of leishmania to determine whether injection of L. gerbilli in mice could protect them against later L. major inoculation. Eighty female BALB/c mice were divided by random in eight groups. Promastigotes of L. major and L. gerbilli were used. Mice were inoculated with three different doses of L. gerbilli (3 x 10(6), 2 x 10(7) and 5 x 10(7)) via subcutaneous (SC) in the base of their tails or interpretoen (IP). Forty days after the first injection, all mice received the same doses as a booster. Two control groups received PBS (SC or IP) only. All BALB/c mice were inoculated subcutaneously with 2 x 10(6). Promastigotes of L. major in the base of their tails after 75 days of the first injection of L. gerbilli. When leishmania lesion developed (35 days after challenge), the size was measured and continued once a week for 12 weeks. Meanwhile, the liver and spleen samples of dead mice moved to culture media and examined for the parasite. Delayed Type Hypersensitivity (DTH) and immunoflurecent tests were used to determine results of immunization. Compared with the control group and the other groups that received different doses of L. gerbilli via IP, an evident decrease in lesion size was observed in group that received 2 x 10(7) promastigotes (p < 0.05). By contrast, in those groups received L. gerbilli subcutaneously, no difference was observed through the different doses of inoculated parasite. Comparison of the inoculation styles showed that IP method caused smaller lesions than SC (p < 0.05).