Comparative analysis of the RVA VP7 and VP4 antigenic epitopes circulating in Iran and the Rotarix and RotaTeq vaccines.

Analyzing the lineages and detecting antigenic variation in immunogenic motifs of Group A Rotavirus (RVA) variants is crucial because it can impact vaccine efficacy. This study investigated the circulating lineages of VP4 and VP7 proteins of human RVA isolates and their phylogeny in ≤24-month-old symptomatic, rotavirus-positive children with transudative diarrhea within 48 h of admission to Mofid Children's Hospital between December 2020 and March 2022 in Tehran, Iran. Antigen detection was performed by ELISA, RNA extraction, and semi-nested multiplex PCR for G/P genotypes, followed by sequencing and bioinformatic analysis using multiple sequence alignments in MEGA and phylogenetic analysis by Geneious Prime. The similarity of VP7 and VP4 amino acids with the RotaTeq and Rotarix vaccine strains for cytotoxic T cell and antigenic epitopes was evaluated using the UCSF Chimera Molecular Modeling System. Overall, 27.3 % of the samples were RVA positive, showing untypeable (2.5 %), single (76.9 %), and mixed (20.5 %) genotypic characteristics. The strains clustered in the G1/II, G2/IV, G3/I, G4/I, G9/III, P (Kachooei et al., 2023) [8]/III, P (Howley et al., 2020) [4]/V, and P (Wahyuni et al., 2021) [6]/I lineages. Comparative analysis of VP7 antigenic epitopes showed that the G1/II strains were completely conserved, while the G2/IV, G3/I, G4/I, G6, G9/III strains contained 2, 3-5, 2, 4 and 9 amino acid substitutions, respectively. The P (Kachooei et al., 2023) [8]/III genotypes differed by 3 amino acids, while the P (Wahyuni et al., 2021) [6]/I genotype had the most substitutions. CTL epitopes were completely conserved in G3/I strains, but other genotypes differed by 1-4 amino acids compared to the vaccine strains. Given the diversity of circulating RVA genotypes and the observed mutations in neutralizing and CTL epitopes, immune escape by some of the strains is likely in Iran. This finding underscores the importance of evaluating the effect of rotavirus vaccines on local genotypes and related lineages before implementing a vaccination program.

Multicenter Study of Rotavirus Infection, Diversity of Circulating Genotypes and Clinical Outcomes in Children ≤5 Years Old in Iran.

BACKGROUND: To determine the epidemiology of rotavirus group A (RVA) infection in symptomatic children, and analyze genotype diversity in association with clinical characteristics, geographical and seasonal changes. METHODS: The stool samples of symptomatic children 5≥ years old were collected from 5 different hospitals during December 2020 and March 2022. Rotavirus stool antigen test was done and G and P genotypes of the positive samples were determined. Associations of the infection and genotype diversity with demographical and clinical data were assessed by statistical methods. RESULTS: RVA infection was detected in 32.1% (300/934) of the patients (Ranges between 28.4% and 47.4%). An inverse association with age was detected, where the highest frequency was measured in children ≤12 months of age (175/482, 36.3%). The infection was more frequent during winter (124/284, 43.7%) and spring (64/187, 34.2%). Children who were exclusively fed with breast milk showed a lower rate of infection (72/251, 28.6%). Among the 46 characterized genotypes (17 single- and 29 mixed-genotype infections), G1P[8] and G9P[4] were more frequently detected in children <36 (67/234, 28.63%) and 36-60 (7/24, 29.16%) months of age children, respectively. A seasonal diversity in the circulating genotypes was detected in different cities. Children with G1P[8], G1P[6], and mixed-genotype infection experienced a shorter duration of hospitalization, and a higher frequency of nausea and severe diarrhea, respectively. CONCLUSIONS: In this study high frequency of RVA infection was detected in symptomatic children in Iran. Moreover, genotype diversity according to geographic area, seasons, age groups, and clinical features of disease was detected.

Environmental Surveillance of Poliovirus and Non-polio Enteroviruses in Iran, 2017-2023: First Report of Imported Wild Poliovirus Type 1 Since 2000.

In Iran, which is at high risk of the Wild Poliovirus (WPV) and Vaccine-Derived Poliovirus (VDPV) importation due to its neighborhood with two polio endemic countries, Pakistan and Afghanistan, Environmental Surveillance (ES) was established in November 2017. Sistan-Balouchestan province was chosen for the ES due to its vicinity with Pakistan and Afghanistan. Five sewage collection sites in 4 cities (Zahedan, Zabol, Chabahar and Konarak) were selected in the high-risk areas. Since the establishment of ES in November 2017 till the end of 2023, 364 sewage specimens were collected and analyzed. The ES detected polioviruses which have the highest significance for polio eradication program, that is, Wild Poliovirus type 1 (WPV1) and Poliovirus type 2 (PV2). In April and May 2019, three of 364 (0.8%) sewage specimens from Konarak were positive for imported WPV1. According to phylogenetic analysis, they were highly related to WPV1 circulating in Karachi (Sindh province) in Pakistan. PV2 was also detected in 5.7% (21/364) of the sewage specimens, most of which proved to be imported from the neighboring countries. Of 21 isolated PV2s, 7 were VDPV2, of which 5 proved to be imported from the neighboring countries as there was VDPV2 circulating in Pakistan at the time of sampling, and 2 were ambiguous VDPVs (aVDPV) with unknown source. According to the findings of this study, as long as WPV1 and VDPV2 outbreaks are detected in Iran's neighboring countries, there is a definite need for continuation and expansion of the environmental surveillance.

COVID-19 Vaccine Intention Among Iranian Health Workers: Application of the HBM Model.

The study aimed to determine the application of the health belief model (HBM) in the acceptance of COVID-19 vaccination among health workers in 2021. The cross-sectional study was conducted on 3600 health workers from February to March 2021. Data was collected using a researcher-made questionnaire that included the intention to receive vaccines based on the health belief model constructs. Data were analyzed using descriptive statistics indicators, Chi-square, ANOVA test, and logistic regression model at a 95% confidence level. More than 62% of the participants intended to receive the vaccine. The odds of intention to receive the vaccine among people who worked in the health center and did not have a history of hospitalization due to COVID-19 disease were 1.50 and 2.10 units more than the others. Intention to receive the vaccine in individuals with high perceived sensitivity was 1.10 units. Furthermore, in terms of perceived benefits, self-efficacy, and cue-to-action constructs were 1.15, 1.34, and 1.65 units respectively. The rate of vaccine acceptance among Iranian health care workers was relatively good and the constructs of HBM in predicting the rate of intention to receive the vaccine had good applicability.