Effectiveness of different vaccine platforms in reducing mortality and length of ICU stay in severe and critical cases of COVID-19 in the Omicron variant era: A national cohort study in Iran.

Various severe acute respiratory syndrome coronavirus 2 vaccines with different platforms have been administered worldwide; however, their effectiveness in critical cases of COVID-19 has remained a concern. In this national cohort study, 24 016 intensive care unit (ICU) coronavirus disease-2019 (COVID-19) admissions were included from January to April 2022. The mortality and length of ICU stay were compared between the vaccinated and unvaccinated patients. A total of 9428 (39.25%) patients were unvaccinated, and 14 588 (60.75%) patients had received at least one dose of the vaccine. Compared with the unvaccinated, the first, second, and third doses of vaccine resulted in 8%, 20%, and 33% lower risk of ICU mortality in the adjusted model, with risk ratio (RR): 0.92, 95% confidence interval (CI): 0.84-1.001, RR: 0.80, 95% CI: 0.77-0.83, and RR: 0.67, 95% CI: 0.64-0.71, respectively. The mean survival time was significantly shorter in the unvaccinated versus the fully vaccinated patients (hazard ratio [HR]: 0.84, 95% CI: 0.80-0.88); p < 0.001). All vaccine platforms successfully decreased the hazard of ICU death compared with the unvaccinated group. The duration of ICU stay was significantly shorter in the fully vaccinated than in unvaccinated group (MD, -0.62, 95% CI: -0.82 to -0.42; p < 0.001). Since COVID-19 vaccination in all doses and platforms has been able to reduce the risk of mortality and length of ICU-stay, universal vaccination is recommended based on vaccine availability.

Molecular typing of enteroviruses and parechoviruses in acute flaccid paralysis patients in Iran in 2019.

Enteroviruses (EVs) and parechoviruses (PeVs) are among the viral pathogens that can cause acute flaccid paralysis (AFP). There is not sufficient information about direct detection of EVs and PeVs in AFP patients in Iran. The aim of this study was to conduct a one-year study for direct detection and molecular typing of EVs and PeVs from stool samples of AFP patients in Iran. One hundred stool samples from polio-negative AFP patients who were referred to the Iran National Polio Laboratory were randomly chosen and analyzed during 2019. A one-step TaqMan probe-based real-time RT-PCR assay targeting the 5'-untranslated region (5' -UTR) was used to screen for EVs and PeVs. All positive samples were genotyped by direct sequencing, targeting the VP1 region of the genome. In total, twelve (12%) and four (4%) stool samples from polio-negative AFP children were positive for EVs and PeVs, respectively. Sequence analysis revealed the presence of echovirus 2 (E2), echovirus 13 (E13), echovirus 25 (E25), echovirus 30 (E30), coxsackievirus A2 (CVA2), coxsackievirus A9 (CVA9), coxsackievirus A16 (CVA16), human enterovirus A76 (HEV-A76), and human parechovirus 1 (HPeV1) in children with AFP-like symptoms. Phylogenetic analysis showed that E2 strains clustered together with the strains circulating in the Netherlands during 2014, whereas the PeV strains belonged to different lineages. This study demonstrates that different EV types are associated with AFP cases in Iran. However, the frequency of association of PeVs with AFP cases appears to be low.

Determinants of COVID-19 vaccine acceptance in healthcare workers in Iran: National Survey.

BACKGROUND AND AIM: It seems that acceptance of COVID-19 vaccination is the most effective way to tackle the COVID-19 pandemic now. Health care workers (HCWs) are one of the most important groups who are at risk for COVID-19 infection. This study aimed to assess the COVID-19 vaccine acceptance among HCWs in Iran and its determinants. METHODS: A cross-sectional survey was carried out among 3600 HCWs in Iran. Data were collected through a self-administered questionnaire by a trained team from February to March 2021. Multi-stage cluster sampling method was used for selecting respondents of the study. Multivariate logistic regression analysis was used to determine the key factors of COVID-19 vaccine acceptance among participants. P-value < 0.05 was considered statistically significant. RESULTS: Out of the 3536 respondents, 2191 (62.1%) intended to uptake the COVID-19 vaccine. Only about 10 percent of respondents said they did not trust any vaccine (domestic or foreign). Willing to accept a COVID-19 vaccine was relatively high among males, doctors, and those who had a history of hospitalization due to COVID-19 infection. The multivariate regression analysis showed respondents who were 40-50 years (aOR: 1.56; 95% CI: 1.47-1.66), had a history of COVID-19 infection (aOR: 0.85; 95% CI: 0.83-0.88), and hospitalized due to COVID-19 infection (aOR: 2.18; 95% CI: 1.97-2.39), were significantly associated with vaccine acceptance (p < 0.05). CONCLUSION: Our study showed moderate acceptance of COVID-19 vaccination in the HCWs in the Islamic Republic of Iran. The most important factor in the acceptance of the COVID-19 vaccine by the health staff is having a history of hospitalization. Further training and justification of health personnel is needed to increase the acceptance of COVID 19 vaccine.

Risk Communication in Early Containment of COVID-19 Pandemic in Iran: Implementation of the World Health Organization Strategic Preparedness and Response Plan (WHO-SPRP).

Background: Health systems must have functional and efficient preparedness and response plans to manage pandemics. Moreover, it is essential to adjust to changing circumstances and the dynamic character of pandemics. The World Health Organization (WHO) introduced the Strategic Preparedness and Response Plan (SPRP), emphasizing 144 measures across 10 pillars, helping governments prepare and respond to the coronavirus disease 2019 (COVID-19) pandemic. This study aimed to determine how the Iranian health system, based on the WHO-SPRP, addresses strategic preparedness and response plan in the COVID-19 pandemic at the national level. Methods: The WHO-SPRP was adopted and translated into Persian by 2 bilingual natives. The chief of the health office requested that authorized officers complete the SPRP. Then, a meeting was held by officers of related units involved in COVID-19 management to address the SPRP at regional and national levels. Results: Our findings suggest that up to August 2020, effective risk communication and community engagement were not fully established. Our response plan lacked evidence-based information and educational messaging to consistently shape public opinion and impression of a respiratory pandemic. Conclusion: The Iranian health care system and services were almost able to address the SPRP and perform the major indicators that the WHO had proposed. However, special attention should be paid to risk communication and community engagement to empower informed decision-making by individuals and communities.

Seroprevalence of Bordetella pertussis among a nationally representative sample of Iranian pediatric population: The childhood and adolescence surveillance and prevention of adult noncommunicable disease-V study.

BACKGROUND: Pertussis is a vaccine-preventable respiratory infection and seroepidemiology of the infection could be a marker of the pertussis immunity in a population. In many countries, despite vaccination coverage, high prevalence of pertussis has been observed. The present study aimed to evaluate the immunoglobulin G (IgG) antibody against pertussis and the role of demographic and anthropometric variables on the immunity rate in the Iranian pediatric population to evaluate the impact of existing immunization program in order to envisage future vaccination strategies to prevent infection. METHODS: In a cross-sectional multi-centric study, 1593 samples of the students aged 7-18 years, who had been enrolled in a national survey (Childhood and Adolescence Surveillance and Prevention of Adult Noncommunicable disease-V), were randomly selected and tested for IgG antibody against Bordetella pertussis (BP) by enzyme-linked immunosorbent assay. The age, gender, education, residency, geographical region, and body mass index (BMI) were extracted from the questionnaires of the COSPIAN-Survey. Multiple logistic regression models were used to assess the associations between the variables with the IgG antibody against BP. Data were presented by odds ratio (OR), 95% confidence interval (95% CI) and P values (P): (OR [95% CI]; P). RESULTS: Subjects were consisted of 774 boys and 750 girls, with a mean (standard deviation) age of 12.39 (3.03) years. Overall, BP seroprevalence was 59.8%. There were higher BMI values in seronegative ones versus seropositive (18.62 ± 4.07 vs. 18.15 ± 3.94, P = 0.041, 95% CI = 0.23 [0.02-0.92]). However, the categorized BMI for age was not significantly associated with IgG levels (0.27 [0.25-0.29]; 0.27). BP seroprevalence was not significantly different between geographical regions (0.06 [0.05-0.07]; 0.06), genders (1.17 [0.93-1.47]; 0.18), area of residence (1.07 [0.82-1.4]; 0.61), and educational levels (0.94 [0.75-1.19]; 0.62). CONCLUSION: IgG antibody against pertussis was not detected in nearly 40% of the subjects who had history of vaccination against pertussis. It is recommended to monitor the incidence of pertussis in high-risk populations closely and administer a booster dose of acellular pertussis vaccine in adolescents.

Geographical distribution of Typhoid using Geographic Information System (GIS) during 2009-2014 in Iran.

Background: Salmonella induced infections remain one of the most important health problems worldwide. The purpose of this study is to investigate the incidence and geographical distribution of typhoid using GIS and to predict its incidence in Iran in 2021. Methods: This study is a descriptive analytical study. Information on pertussis was obtained from the Center for Communicable Diseases Control during 2009-2015. In the next step, ArcGIS 9.3 was used to prepare geographic maps of the disease incidence and frequency Therefore, using the Raster Calculator tool, the disease prediction map was drawn. Results: The results showed that the highest incidence of typhoid during 2009-2014 was in Kermanshah, Lorestan, Hamadan, Kurdistan, and Ilam provinces. The incidence of typhoid in Iran increased during 2009-2010. The annual incidence of typhoid decreased from 0.85 per 100,000 in 2010 to 0.5 in 2014. Based on the modeling results for Iran, Kermanshah, Lorestan, Kurdistan, Ilam and Hamadan provinces with 92.17%, 46.56%, 31.74%, 25.62% and 22.96% of their areas (Km2) are at high risk for typhoid in the coming years, respectively. Conclusion: Considering that the provinces of Kermanshah, Lorestan, Kurdistan, Ilam, and Hamadan are at risk of typhoid incidence in the coming years in Iran, and given that salmonella infections have a direct relationship with the individual's health status and individual's environmental health and socioeconomic status, improving the health status and disease control in carriers as well as improving the socio-economic status of the population living in these areas can prevent the disease in the years to come.

Epidemiology incidence and geographical distribution of Pertussis using GIS and its incidence prediction in Iran in 2021.

Background: Pertussis is a respiratory tract infection caused by Bordetella pertussis, which causes inflammation of the lungs and respiratory tract. The purpose of this study was to investigate the incidence and geographical distribution of pertussis using the geographic information system (GIS) and to predict its incidence in Iran in 2021. Methods: This was a descriptive analytical study. Information on pertussis was obtained from the Center for Communicable Diseases Control during 2009-2015. In the next step, the ArcGIS 9.3 was used to prepare geographic maps of the disease incidence and frequency. Therefore, the disease prediction map was drawn. using the Raster Calculator tool. Results: The results showed that the highest incidence of pertussis during 2009-2015 was in Zanjan, Qom, Mazandaran, and Qazvin provinces. The incidence of pertussis in Iran increased from 0.74 in 2009 to 1.53 in 2015. Based on the modeling results for Iran, Qom, Mazandaran, Tehran, Qazvin, and Zanjan provinces, with 76.76%, 73.69%, 66.32%, 30.94% and 24.18% of their areas (Km2), are at high risk for pertussis in the coming years, respectively. Conclusion: The incidence of the disease has been increasing in recent years, indicating the emergence of the disease in Iran. The modeling maps show that the Iranian provinces of Qom, Tehran, Zanjan, and Qazvin are at risk of the disease incidence in the coming years, indicating the need for planning, appropriate interventions and more precise implementation of the vaccination program against the disease.

Epidemiology incidence and geographical distribution of Meningitis using GIS and its incidence prediction in Iran in 2021.

Background: Meningitis is classified as a medical emergency where the identification and early treatment of bacterial meningitis can eliminate serious consequences, such as hearing loss, memory problems, learning disabilities, brain damage, seizures, and death. The purpose of this study was to investigate the incidence and geographical distribution of meningitis using Geographic Information system (GIS) and to predict its incidence in Iran in 2021. Methods: This was a descriptive analytical study. Information on pertussis was obtained from the Center for Communicable Diseases Control during 2010-2015. In the next step, ArcGIS 9.3 was used to prepare geographic maps of the disease incidence and frequency. Then, the disease prediction map was drawn using the Raster Calculator tool. Results: The results showed that the highest incidence of meningitis during 2010-2015 was in Qazvin, Qom, and Kurdistan provinces. The incidence of meningitis in Iran increased from 9.77 in 2010 to 10.33 in 2015. Based on the modeling results for Iran, Qom, Qazvin, Kurdistan, Hamadan, and Mazandaran provinces with 78.89%, 74.68%, 70.07%, 43.97%, and 22.93% of their areas (Km2) are at high risk for meningitis in the coming years, respectively. Conclusion: According to the results of this study, it can be concluded that Qom, Qazvin, Kurdistan, Hamedan, and Mazandaran provinces are at risk of the disease. Monitoring vaccination in high-risk groups can partially prevent the incidence of the disease in these areas.

Molecular characterization of non-polio enteroviruses isolated from children with acute flaccid paralysis in IRAN, 2015-2018.

In addition to polioviruses, non-polio enteroviruses (NPEVs) are frequently isolated from patients with acute flaccid paralysis (AFP) worldwide. In polio-free countries, there have been expectations that with disappearing wild poliovirus from the community, the rate of AFP would decrease, but the increasing number of AFP cases proved this notion to be wrong. There are speculations that NPEVs might be the cause of increasing AFP rate. The aim of this study was to investigate frequency, genetic diversity, circulation patterns of NPEVs isolated from AFP cases in Iran from 2015 to 2018. Fifty-three NPEVs were isolated from stool specimens of AFP cases during four years of AFP surveillance. Nested PCR and VP1 sequencing revealed 20 NPEV types in which Echovirus 3 (13.2%), Echovirus 6 (13.2%), Echovirus 7 (7.5%), Echovirus 13 (7.5%) and Echovirus 21 (7.5%) were the most frequent. Coxsackie B viruses were isolated for the first time in AFP cases in Iran. The phylogenetic analysis of Echovirus 3 and Echovirus 6 revealed that Iranian echovirus strains belonged to the same cluster, indicating these viruses have been circulating in Iran for a long time. Compared to global Echovirus 3 and Echovirus 6 references, Echovirus 3 and Echovirus 6 strains detected in this study were closely related to Indian and Malaysia strains, respectively. The results of this study demonstrated a wide variety of NPEV types in Iranian patients, some of which had not been reported in previous studies. Moreover, this study highlights the need for NPEV surveillance in AFP cases.

Spatio-temporal analysis of Pertussis using geographic information system among Iranian population during 2012-2018.

Background: In spite of existing vaccination programs in many countries, outbreaks of pertussis are still reported. In Iran, the suspected and confirmed cases of pertussis are reported annually. Due to the lack of similar studies, the purpose of the current study was to determine the Spatio-temporal distribution of Pertussis using Geographic Information System (GIS) to identify high-risk areas in Iran during 2012-2018. Methods: In the current cross-sectional study, registered data in the department of vaccine-preventable diseases in the Iranian ministry of health were used. To assess the temporal trend, the Cochran-Armitage test was used. To show the spatial distribution and to identify hotspot areas, Choropleth map and Getis-Ord Gi statistics were used. All analyses performed by Arc.map10.5, Stata 15 and Excel 2010. Results: The incidence of suspect pertussis cases had an increasing trend but did not have a linear trend (p=0.06). Most of the cases happened in under 1 year infants (62.66%). The incidence of reported cases in northern areas was higher than in the Southern areas. The Zanjan had the most reported cases during the understudied period with a median of 7.63 reported cases per 100,000. The clustering of infection and hotspots were identified in northern areas of Iran including Qazvin, Qom, Markazi, and Hamadan. Conclusion: Our results showed that the cumulative incidence of reported cases is increasing. The northern provinces had the highest incidence of Pertussis. Therefore, the causes of this spatio-temporal pattern of pertussis should be determined. Also, supervision on vaccination programs in high-risk areas is recommended.

Vaccine-Derived Poliovirus Infection among Patients with Primary Immunodeficiency and Effect of Patient Screening on Disease Outcomes, Iran.

Patients with immunodeficiency-associated vaccine-derived poliovirus (iVDPV) are potential poliovirus reservoirs in the posteradication era that might reintroduce polioviruses into the community. We update the iVDPV registry in Iran by reporting 9 new patients. In addition to national acute flaccid paralysis surveillance, cases were identified by screening nonparalyzed primary immunodeficiency (PID) patients. Overall, 23 iVDPV patients have been identified since 1995. Seven patients (30%) never had paralysis. Poliovirus screening accelerated the iVDPV detection rate in Iran after 2014.The iVDPV infection rate among nonparalyzed patients with adaptive PID was 3.1% (7/224), several folds higher than previous estimates. Severe combined immunodeficiency patients had the highest risk for asymptomatic infection (28.6%) compared with other PIDs. iVDPV2 emergence has decreased after the switch from trivalent to bivalent oral poliovirus vaccine in 2016. However, emergence of iVDPV1 and iVDPV3 continued. Poliovirus screening in PID patients is an essential step in the endgame of polio eradication.

Monitoring progress towards the elimination of measles in Iran: supporting evidence from 2014 to 2016 by application of measles outbreaks data.

BACKGROUND: To achieve the goal of measles eradication, all WHO member countries should continuously monitor the status of measles elimination. This work aims to characterize measles outbreaks in Iran from 2014 to 2016 and calculate the effective reproduction number, given that the country has recently eliminated measles. METHODS: Effective Reproduction Number (R) was estimated to achieve the goal of measles elimination using measles related outbreaks data and epidemiological data from the cases linked to imported cases. Three methods were used to estimate R includes (i) proportion of cases imported, (ii) distribution of outbreak size and (iii) distribution of outbreak generations. RESULTS: Of the 153 outbreaks occurring during the three years of the study, 29 outbreaks (19%) were unknown source, 86% of them were single cases. Estimates of R during the study period by proportion of cases imported were 0.79 (95% CI: 0.73-0.86). Corresponding values for distribution of outbreak size and distribution of outbreak generations methods were R = 0.83 (95% CI: 0.68-0.97) and R = 0.76 (95% CI: 0.54-0.90), respectively. CONCLUSIONS: Estimated values of R represent the important achievement that the outbreaks of measles originating from the indigenous genotype in Iran have been eliminated. Moreover, Iran has also achieved the goal of measles elimination by end of 2015.

Epidemiological profile of meningitis in Iran before pentavalent vaccine introduction.

BACKGROUND: No reliable and comprehensive study has been published on the incidence and epidemiological profile of meningitis in Iran from 2008 to 2014, before pneumococcal conjugate vaccine (PCV) and pentavalent vaccine (DTPw-Hep B-Hib (PRP-T) vaccine (pentavac) (adsorbed)) introduction. The present study aimed to portray the epidemiological profile of meningitis in Iran from 2008 to 2014. METHODS: Data on meningitis cases aged from 1 day to 110 years were extracted from national notifiable diseases surveillance system from March 2008 to December 2014 in Iran. A total number of 48,006 cases of suspected meningitis were identified and 1468 cases of which met the criteria for diagnosis-confirmed meningitis. Of 1468 cases, 1352 patients were included in the study. RESULTS: The great number of cases reported from urban areas. Moreover, males were more predominant than females (58.51% vs. 33.81%) in total. The estimated annual incidence rate of meningitis varied from 0.28/100000 in 2008 to 0.09/100000 in 2014. Streptococcus pneumoniae, Haemophilus influenzae and Neisseria meningitidis were the most leading pathogens causing bacterial meningitis, accounted for 266(23.44%), 145(12.78%), 95(8.37%) of cases, respectively. Each of the three bacterial species showed a descending trend. The majority of infected subjects are children under five years. CONCLUSIONS: Unlike the decreasing trend of meningitis and high percentage of cultures with negative results, according to World Health Organization recommendation PCV introduction into routine immunization is evident. Implementing an enhanced surveillance system to provide high quality data on epidemiological profile of meningitis in Iran is necessary.

Accuracy and quality of immunization data in Iran: findings from data quality self-assessment survey in 2017.

BACKGROUND: The aim of this study was to assess the accuracy and quality of immunization data on the pentavalent (diphtheria, pertussis, tetanus, hepatitis B and Haemophilus influenzae type B (Hib)) and MMR vaccines as the administrative data of the expanded program on immunization (EPI) in Iran. METHODS: We conducted a Data Quality Self-assessment (DQS) survey from October to December 2017. Standardized DQS tools were used to assess the accuracy of reported immunizations data and quality of the immunization monitoring system at the provincial level of the healthcare system including health houses, health posts, rural and urban health centers and district health centers. Multistage cluster random sampling with proportional to size (PPS) weights was used to select target provinces and related health units. Accuracy ratio, quality index (QI), completeness and relevant quality indices of first dose of MMR (MMR1) and third dose of pentavalent vaccines were reported. Corresponding period of the survey was limited to reported administrative immunization data during the first 6 months of 2016. RESULTS: In relation to accuracy ratio, there was some evidence of under reporting of pentavalent (3rd dose) and MMR1 vaccines in health house units which were 100.94 and 101.1%, respectively. Completeness of reporting for both vaccines at different provincial levels was near 100%. However, the corresponding value for pentavalent (3rd dose) and MMR1 vaccines at the level of urban health centers was 96.67 and 94.17% respectively. Among the five components of a monitoring system data usage and core output had the lowest QI scores in either rural or urban as well as district healthcare centers. CONCLUSIONS: Findings from our DQS survey reveals that administrative reporting of the immunization data was adequate at provincial and district levels of the healthcare centers. Although, addressing the existing concerns regarding timelines of the reporting by health authorities and staffs of EPI is warranted.

The spatial analysis of annual measles incidence and transition threat assessment in Iran in 2016.

Background: During the past years, due to the increase in immunization coverage and promotion of surveillance data, the incidence of measles decreased. This study aimed to determine the measles incidence risk, to conduct spatial mapping of annual measles incidence, and to assess the transition threat in different districts of Iran. Methods: A historical cohort study with retrospective data was conducted. The measles surveillance data containing 14 294 cases suspected of having measles in Iran were analyzed during 2014-2016. WHO Measles Programmatic Risk Assessment Tool was applied to calculate and map the incidence of measles in each district, to determine the annual incidence rate, and to conduct spatial threat assessment risk. Threat assessment was measured based on factors influencing the exposure and transmission of measles virus in the population. The annual measles incidence rate and spatial mapping of incidence in each Iranian district was conducted by Measles Programmatic Risk Assessment Tool. Data were analyzed by descriptive statistics in Excel 2013 and Arc GIS 10.3. Results: Of 14 294 suspected cases, 0.6% (CI 95%: 0.599-0.619) were identified as clinically compatible measles, 0.280 (CI 95%: 0.275-0.284) as confirmed rubella, 0.52% (CI 95%: 0.516-0.533) as epi-linked measles, 4.6% (CI 95%: 0.450-0.464) as lab-confirmed measles, and 94% (CI 95%: 93.93-94.11) were discarded. The annual incidence rate in cases per 100 000 populations increased from 0.0726, (CI 95%; 0.0714-0.0738) in 2014 to 0.1154 (CI 95%; 0.1135-0.1173) in 2016, and the 3-year incidence rate during the study period was 1.032 (CI 95%; 1.017-1.047) and the annual average was 0.3442 (CI 95%; 0.3387-0.3496). Conclusion: The average annual incidence rate of measles in Iran was low, but after a 11-fold increase in the number of measles cases in 2015, the number of measles cases decreased to more than 7-times in 2016. However, maintaning a high immunization coverage of measles and timely vaccination can be effective in reaching the goal of measles elimination.

Strain variation and antigenic divergence among Bordetella pertussis circulating strains isolated from patients in Iran.

Despite global efforts and widespread vaccination to control whooping cough (pertussis) caused by B. pertussis, the re-emergence of pertussis still is being reported all over the world. Antigenic divergence in B. pertussis virulence factors is one of the reasons of pertussis resurgence, resulting in dissimilarity of local and vaccine strains. In this study, clonal spread and variation of B. pertussis virulence factor in isolated strains from Iranian patients have been analyzed. A total of 100 B. pertussis isolates were obtained from Pertussis Reference Laboratory of Pasteur Institute of Iran. Real-time PCR were performed to confirm the B. pertussis strains. The genomic patterns of B. pertussis strains were analyzed by pulsed-field gel electrophoresis (PFGE). Predominant alleles of local strains were ptxP3, ptxA1, prn2, fim 2-1, fim3-2, and cya2. PFGE results showed 25 patterns clustered into 18 PFGE groups. A few similarities between the circulating isolates, vaccine, and standard strains were obtained. Significantly, 48% of the isolates showed dominant pattern with different allelic profiles from vaccine strains. According to the genomic profiles, the clonal spread was observed among the circulating strains. Predominant virulence factor profile was also comparable with other countries. It may be suggested that strain variation between vaccine and local strains may have an effect on pertussis resurgence in Iran like other parts of the world.

Adverse events following immunization with pentavalent vaccine: experiences of newly introduced vaccine in Iran.

BACKGROUND: The 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. METHODS: This 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. RESULTS: The 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. CONCLUSION: Further 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.

Vaccine-Derived Polioviruses and Children with Primary Immunodeficiency, Iran, 1995-2014.

Widespread use of oral poliovirus vaccine has led to an ≈99.9% decrease in global incidence of poliomyelitis (from ≈350,000 cases in 1988 to 74 cases in 2015) and eradication of wild-type poliovirus serotypes 2 and 3. However, patients with primary immunodeficiency might shed vaccine-derived polioviruses (VDPVs) for an extended period, which could pose a major threat to polio eradication programs. Since 1995, sixteen VDPV populations have been isolated from 14 patients with immunodeficiency in Iran. For these patients, vaccine-associated paralysis, mostly in >1 extremity, was the first manifestation of primary immunodeficiency. Seven patients with humoral immunodeficiency cleared VDPV infection more frequently than did 6 patients with combined immunodeficiencies. Our results raise questions about manifestations of VDPVs in immunodeficient patients and the role of cellular immunity against enterovirus infections. On the basis of an association between VDPVs and immunodeficiency, we advocate screening of patients with primary immunodeficiency for shedding of polioviruses.

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.

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.