Use of Oral Polio Vaccine and the Global Incidence of Mother-to-Child Human Immunodeficiency Virus Transmission.

Background: Mother-to-child transmission (MTCT) of human immunodeficiency virus (HIV) is an important global health issue. We hypothesized that the live attenuated poliovirus existing in oral polio vaccine (OPV) may protect uninfected neonates born to HIV-positive mothers through the stimulation of innate immune system. Objective: To test the hypothesis that countries using OPV have a lower MTCT rate (due to postnatal protection provided by the vaccine) compared with those using only inactivated polio vaccine (IPV). Methods: In an ecological study, the incidence of HIV/AIDS in children aged <1 year (IncHIV1), considered a surrogate index for MTCT rate, was compared between countries using OPV vs. IPV. The aggregated population data were retrieved for 204 countries from the Global Burden of Disease (GBD 2019) Collaborative Network website, "Our World in Data" website, the World Bank website, and the WHO Global Polio Eradication Initiative (GPEI). We used a negative binomial regression model with IncHIV1 as the dependent variable and the prevalence of HIV/AIDS in women aged 15-49 years (PrevHIV), antiretroviral therapy (ART) coverage, human development index (HDI), and the type of vaccine used in each country as independent variables. Multivariate imputation by chained equations was used to treat missing values. Analyses were performed for both the original dataset (with missing values) and the five imputed datasets. Results: IncHIV1 and PrevHIV were available for all 204 countries; vaccine type, 194 countries; HDI, 182 countries; and ART coverage, 133 countries. One-hundred and twenty-nine countries in the original dataset had complete data for all the above-mentioned variables; the imputed datasets had complete data for all 204 countries. The results obtained from the analysis of the original dataset had no overall difference with the pooled results obtained from the analysis of the five imputed datasets. Countries with higher HDI mainly use IPV; those with lower HDI commonly use OPV. PrevHIV, HDI, and the type of vaccine were independent predictors of IncHIV1. Use of OPV compared to IPV, was independently associated with an average decrease of 17% in IncHIV1 at the median HDI of 0.75. The protection provided by OPV increased in countries with lower HDI. Conclusions: Use of OPV compared with IPV, was independently associated with lower MTCT rate.

Use of oral polio vaccine and the incidence of COVID-19 in the world.

BACKGROUND: Several live attenuated vaccines were shown to provide temporary protection against a variety of infectious diseases through stimulation of the host innate immune system. OBJECTIVE: To test the hypothesis that countries using oral polio vaccine (OPV) have a lower cumulative number of cases diagnosed with COVID-19 per 100,000 population (CP100K) compared with those using only inactivated polio vaccine (IPV). METHODS: In an ecological study, the CP100K was compared between countries using OPV vs IPV. We used a random-effect meta-analysis technique to estimate the pooled mean for CP100K. We also used negative binomial regression with CP100K as the dependent variable and the human development index (HDI) and the type of vaccine used as independent variables. RESULTS: The pooled estimated mean CP100K was 4970 (95% CI 4030 to 5900) cases per 100,000 population for countries using IPV, significantly (p<0.001) higher than that for countries using OPV-1580 (1190 to 1960). Countries with higher HDI prefer to use IPV; those with lower HDI commonly use OPV. Both HDI and the type of vaccine were independent predictors of CP100K. Use of OPV compared to IPV could independently decrease the CP100K by an average of 30% at the mean HDI of 0.72. CONCLUSIONS: Countries using OPV have a lower incidence of COVID-19 compared to those using IPV. This might suggest that OPV may either prevent SARS-CoV-2 infection at individual level or slow down the transmission at the community level.

COVID-19 Infection Among Women in Iran Exposed vs Unexposed to Children Who Received Attenuated Poliovirus Used in Oral Polio Vaccine.

Importance: Live attenuated vaccines may provide short-term protection against infectious diseases through stimulation of the innate immune system. Objective: To evaluate whether passive exposure to live attenuated poliovirus is associated with diminished symptomatic infection with SARS-CoV-2. Design, Setting, and Participants: In a longitudinal cohort study involving 87 923 people conducted between March 20 and December 20, 2020, the incidence of COVID-19 was compared between 2 groups of aged-matched women with and without exposure to live attenuated poliovirus in the oral polio vaccine (OPV). Participants were people receiving health care services from the Petroleum Industry Health Organization and residing in 2 cities in Iran (ie, Ahwaz and Shiraz). Participants were women aged 18 to 48 years whose children were aged 18 months or younger and a group of age-matched women from the same residence who had had no potential exposure to OPV. Exposures: Indirect exposure to live attenuated poliovirus in OPV. Main Outcomes and Measures: Symptomatic COVID-19, diagnosed by reverse transcription-polymerase chain reaction. Results: After applying the inclusion and exclusion criteria, 419 mothers (mean [SD] age, 35.5 [4.9] years) indirectly exposed to the OPV and 3771 age-matched women (mean [SD] age, 35.7 [5.3] years) who had no exposure to OPV were available for analysis. COVID-19 was diagnosed in 1319 of the 87 923 individuals in the study population (151 per 10 000 population) during the study period. None of the mothers whose children received OPV developed COVID-19 after a median follow-up of 141 days (IQR, 92-188 days; range, 1-270 days); 28 women (0.74%; 95% CI, 0.47%-1.02%) in the unexposed group were diagnosed with COVID-19 during the 9 months of the study. Point-by-point comparison of the survival curves of the exposed and unexposed groups found that indirect exposure to OPV was significantly associated with decreased COVID-19 acquisition; probability of remaining without infection was 1.000 (95% CI, 1.000-1.000) in the exposed group vs 0.993 (95% CI, 0.990-0.995) in the unexposed group after 9 months (P < .001). Conclusions and Relevance: In this cohort study, indirect exposure to live attenuated poliovirus was associated with decreased symptomatic infection with COVID-19. Further study of the potential protective effect of OPV should be conducted, especially in nations where OPV is already in use for polio prevention and specific COVID-19 vaccines are delayed, less affordable, or fail to meet demand.

Accessing free quality health care services and premature death.

BACKGROUND: The type of health insurance may affect the likelihood of mortality of insured people. We conducted this study to determine if accessing free quality health care services could decrease the premature mortality of people in a developing country. METHODS: In a multicenter cross sectional study, "years-life-lost" (YLL) due to premature death was evaluated in 202 671 insured people residing in six large regions in Iran. The participants had access to free quality health care services. The number of insured people that died in the six regions during March 20, 2014, to March 20, 2015, as well as their sex, age, and cause of the death, were collected, and the YLL was calculated based on assumptions made in Global Burden of Disease Study 2010 (GBD2010). RESULTS: The crude mortality rate was 2.3 per 1000, significantly lower than the overall rate of 4.6 per 1000 people in general population of Iran. The average YLL was 47 years per 1000 persons, significantly lower than that in general population of Iran and many industrialized countries. The most common causes of death (and YLL) were cardiovascular diseases and malignancies. CONCLUSION: Having access to free quality health care services is associated with a significant decrease in premature death.

Knowledge of and attitudes toward breast self-examination in Iranian women: a multi-center study.

BACKGROUND: In Iran, breast cancer is the second most common malignancy among women and diagnosed in advanced stages almost a decade earlier than women living in western countries. OBJECTIVE: To determine the level of knowledge and attitudes toward breast self-examination (BSE) among Iranian women. METHODS: In a cross-sectional multi-center study, 3,060 women aged between 25 and 54 years attending between July and October 2009 to 11 general health care centers located in 11 cities of Iran, were interviewed to assess their knowledge and attitudes toward BSE. RESULTS: Of the total, the data of 3,030 were found eligible for analyses. The median (interquartile range [IQR]) age of participants was 40 (14) years; 2,687 (88.7%) were married; 1496 (49.4%) women performed BSE, 290 of whom (19.4% of performers and 9.6% of all studied women) did it using a correct method and at an appropriate time. More than three-quarters of performers (n=1141) learned about BSE from a health care provider; 248 (16.6%, 95% confidence interval [CI]: 14.7% to 18.5%) had abnormal findings, 11 (0.7% , 95% CI: 0.3% to 1.2%) of which were malignant. Of 1,534 (50.6%) non-performers, 474 (30.9%) did not know how to do BSE; the remaining women did not do BSE for fear of being found positive for cancer or did not care about it. Being a health care provider, married, educated, and knowing of a person with breast cancer was associated with performing BSE. CONCLUSIONS: The level of BSE practice and knowledge among Iranian women is unsatisfactory. We should emphasize appropriate education of women.