National Immunization Campaigns With Oral Polio Vaccine May Reduce All-cause Mortality: An Analysis of 13 Years of Demographic Surveillance Data From an Urban African Area.

BACKGROUND: Between 2002 and 2014, Guinea-Bissau had 17 national campaigns with oral polio vaccine (OPV) as well as campaigns with vitamin A supplementation (VAS), measles vaccine (MV), and H1N1 influenza vaccine. We examined the impact of these campaigns on child survival. METHODS: We examined the mortality rate between 1 day and 3 years of age of all children in the study area. We used Cox models with age as underlying time to calculate adjusted mortality rate ratios (MRRs) between "after-campaign" mortality and "before-campaign" mortality, adjusted for temporal change in mortality and stratified for season at risk. RESULTS: Mortality was lower after OPV-only campaigns than before, with an MRR for after-campaign vs before-campaign being 0.75 (95% confidence interval [CI], .67-.85). Other campaigns did not have similar effects, the MRR being 1.22 (95% CI, 1.04-1.44) for OPV + VAS campaigns, 1.39 (95% CI, 1.20-1.61) for VAS-only campaigns, 1.32 (95% CI, 1.09-1.60) for MV + VAS campaigns, and 1.13 (95% CI, .86-1.49) for the H1N1 campaign. Thus, all other campaigns differed significantly from the effect of OPV-only campaigns. Effects did not differ for trivalent, bivalent, or monovalent strains of OPV. With each additional campaign of OPV only, the mortality rate declined further (MRR, 0.86 [95% CI, .81-.92] per campaign). With follow-up to 3 years of age, the number needed to treat to save 1 life with the OPV-only campaign was 50 neonates. CONCLUSIONS: OPV campaigns can have a much larger effect on child survival than otherwise assumed. Stopping OPV campaigns in low-income countries as part of the endgame for polio infection may increase child mortality.

Oral Polio Vaccine to Mitigate the Risk of Illness and Mortality During the Coronavirus Disease 2019 Pandemic: A Cluster-Randomized Trial in Guinea-Bissau.

Background: Oral polio vaccine (OPV) may improve resistance to non-polio-infections. We tested whether OPV reduced the risk of illness and mortality before coronavirus disease 2019 (COVID-19) vaccines were available. Methods: During the early COVID-19 pandemic, houses in urban Guinea-Bissau were randomized 1:1 to intervention or control. Residents aged 50+ years were invited to participate. Participants received bivalent OPV (single dose) or nothing. Rates of mortality, admissions, and consultation for infections (primary composite outcome) during 6 months of follow-up were compared in Cox proportional hazards models adjusted for age and residential area. Secondary outcomes included mortality, admissions, consultations, and symptoms of infection. Results: We followed 3726 participants (OPV, 1580; control, 2146) and registered 66 deaths, 97 admissions, and 298 consultations for infections. OPV did not reduce the risk of the composite outcome overall (hazard ratio [HR] = 0.97; 95% confidence interval [CI], .79-1.18). OPV reduced the risk in males (HR = 0.71; 95% CI, .51-.98) but not in females (HR = 1.18; 95% CI, .91-1.52) (P for same effect = .02). OPV also reduced the risk in Bacillus Calmette-Guérin scar-positive (HR = 0.70; 95% CI, .49-.99) but not in scar-negative participants (HR = 1.13; 95% CI, .89-1.45) (P = .03). OPV had no overall significant effect on mortality (HR = 0.96; 95% CI, .59-1.55), admissions (HR = 0.76; 95% CI, .49-1.17) or recorded consultations (HR = 0.99; 95% CI, .79-1.25), but the OPV group reported more episodes with symptoms of infection (6050 episodes; HR = 1.10 [95% CI, 1.03-1.17]). Conclusions: In line with previous studies, OPV had beneficial nonspecific effects in males.

Penta is associated with an increased female-male mortality ratio: cohort study from Bangladesh.

Diphtheria-tetanus-pertussis (DTP) vaccine may be associated with excess female deaths. There are few studies of possible nonspecific effects of the DTP-containing vaccine Penta (DTP-hepatitis B-Haemophilus influenzae type b). We therefore investigated whether Penta vaccinations were associated with excess female deaths in rural Bangladesh. Between June 29, 2011 and April 20, 2016, we examined the mortality rates of 7644 children followed between 6 weeks and 9 months of age. We analyzed mortality using crude mortality rate ratio (MRR) and age-adjusted MRR (aMRR) from a Cox proportional hazards model. Mortality was analyzed according to sex, number of doses of Penta, and the order in which BCG and Penta were administered. During follow-up, 43 children died. For children who were only BCG vaccinated (BCG-only), the adjusted F/M MRR was 0.47 (0.09-2.48). However, among children who had Penta as their most recent vaccination, the adjusted F/M MRR was 9.91 (1.16-84.44). Hence, the adjusted F/M MRR differed significantly for BCG-only and for Penta as the most recent administered vaccination. Although the mortality rate was low in rural Bangladesh, there was a marked difference between adjusted F/M MRR's for children vaccinated with BCG-only compared with children where Penta was the most recent administered vaccination. Although usually ascribed to differential treatment and access to care, DTP-containing vaccines may be part of the explanation for the excessive female mortality reported in some regions.