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

Is it time to switch to a formulation other than the live attenuated poliovirus vaccine to prevent poliomyelitis?

The polioviruses (PVs) are mainly transmitted by direct contact with an infected person through the fecal-oral route and respiratory secretions (or more rarely via contaminated water or food) and have a primary tropism for the gut. After their replication in the gut, in rare cases (far less than 1% of the infected individuals), PVs can spread to the central nervous system leading to flaccid paralysis, which can result in respiratory paralysis and death. By the middle of the 20th century, every year the wild polioviruses (WPVs) are supposed to have killed or paralyzed over half a million people. The introduction of the oral poliovirus vaccines (OPVs) through mass vaccination campaigns (combined with better application of hygiene measures), was a success story which enabled the World Health Organization (WHO) to set the global eradication of poliomyelitis as an objective. However this strategy of viral eradication has its limits as the majority of poliomyelitis cases today arise in individuals infected with circulating vaccine-derived polioviruses (cVDPVs) which regain pathogenicity following reversion or recombination. In recent years (between January 2018 and May 2023), the WHO recorded 8.8 times more cases of polio which were linked to the attenuated OPV vaccines (3,442 polio cases after reversion or recombination events) than cases linked to a WPV (390 cases). Recent knowledge of the evolution of RNA viruses and the exchange of genetic material among biological entities of the intestinal microbiota, call for a reassessment of the polio eradication vaccine strategies.

GPTZero Performance in Identifying Artificial Intelligence-Generated Medical Texts: A Preliminary Study

BACKGROUND

With emergence of chatbots to help authors with scientific writings, editors should have tools to identify artificial intelligence-generated texts. GPTZero is among the first websites that has sought media attention claiming to differentiate machine-generated from human-written texts.

METHODS

Using 20 text pieces generated by ChatGPT in response to arbitrary questions on various topics in medicine and 30 pieces chosen from previously published medical articles, the performance of GPTZero was assessed.

RESULTS

GPTZero had a sensitivity of 0.65 (95% confidence interval, 0.41-0.85); specificity, 0.90 (0.73-0.98); accuracy, 0.80 (0.66-0.90); and positive and negative likelihood ratios, 6.5 (2.1-19.9) and 0.4 (0.2-0.7), respectively.

CONCLUSION

GPTZero has a low false-positive (classifying a human-written text as machine-generated) and a high false-negative rate (classifying a machine-generated text as human-written).

Risk of cytomegalovirus diseases among coronavirus disease survivors: A retrospective cohort study

This study was aimed at investigating the risk of cytomegalovirus (CMV) disease among coronavirus disease 2019 (COVID-19) survivors. In this retrospective cohort study, we used the TriNetX research network to identify adults with and without COVID-19 between January 1, 2022 and December 31, 2022. Propensity score matching was used to match the patients with and without COVID-19. The primary outcome was the risk of CMV disease during the 90-day follow-up period. Two matched cohorts comprising 2 501 634 patients with balanced baseline characteristics were created using propensity score matching. During the follow-up period, patients with COVID-19 had a higher risk of CMV disease than those without COVID-19 (hazard ratio [HR], 2.55; 95% confidence interval: 2.01-3.23). The higher risk of CMV disease in the COVID-19 cohort compared with that of the non-COVID-19 cohort remained unchanged in the subgroup analyses by sex (men: HR, 1.85 [1.38-2.47]; women: HR, 2.31 [1.63-3.27]), age (18-64 years: HR, 2.21 [1.71-2.85]; ≥65 years: HR, 1.97 [1.20-3.25]), obesity (HR, 1.54 [1.04-2.30]), diabetes mellitus (HR, 1.50 [1.08-2.08]), cancer (HR, 3.10 [1.95-4.92]), glucocorticoid use (HR, 3.14 [2.45-4.02]), transplantation (HR, 1.38 [1.08-1.77]), and unvaccinated status (HR, 2.37 [1.82-3.08]). In conclusion, COVID-19 can increase the risk of CMV disease. Clinicians should be aware of the risk of CMV disease in patients with COVID-19.

Recent Human Papillomavirus Vaccination is Associated with a Lower Risk of COVID-19: A US Database Cohort Study

OBJECTIVE

To explore the association between human papillomavirus (HPV) vaccination and risk of coronavirus disease 2019 (COVID-19). Specifically, our study aimed to test the hypothesis that HPV vaccination may also induce trained immunity, which would potentially reduce the risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and improve clinical outcomes.

BACKGROUND

Several vaccines have been reported to trigger non-specific immune reactions that could offer protection from heterologous infections. A recent case report showed that verruca vulgaris regressed after COVID-19, suggesting a possible negative association between COVID-19 and HPV infection.

METHODS

We enrolled 57,584 women with HPV vaccination and compared them with propensity score-matched controls who never received HPV vaccination in relation to the risk of COVID-19 incidence. Cox proportional hazard regression analysis was conducted to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Subgroup analyses stratified by age, race, comorbid asthma, and obesity were performed.

RESULTS

The risk of COVID-19 incidence was significantly lower in those who had recently received the HPV vaccine (within 1 year after HPV vaccination, aHR: 0.818, 95% CI 0.764-0.876; within 1-2 years after HPV vaccination, aHR: 0.890, 95% CI 0.824-0.961). Several limitations were recognized in this study, including residual confounding, problems of misclassification due to the use of electronic health record data, and that we were unable to keep track of the patients' HPV infection status and the HPV antibody levels in those who had received the vaccine.

CONCLUSIONS

Recent HPV vaccination was associated with a lower risk of incident COVID-19 and hospitalization. Based on the promising protective effect of HPV vaccine shown in this study, these findings should be replicated in an independent dataset. Further studies are needed to provide a better understanding of the underlying mechanisms and the differences in risks among 2-, 4-, or 9-valent HPV vaccine recipients.

COVID-19 vaccines and a perspective on Africa

Vaccines have dramatically changed the COVID-19 pandemic. Over 30 vaccines that were developed on four main platforms are currently being used globally, but a deep dissection of the immunological mechanisms by which they operate is limited to only a few of them. Here, we review the evidence describing specific aspects of the modes of action of COVID-19 vaccines; these include innate immunity, trained innate immunity, and mucosal responses. We also discuss the use of COVID-19 vaccines in the African continent which is ridden with inequality in its access to vaccines and vaccine-related immunological research. We argue that strengthening immunology research in Africa should inform on fundamental aspects of vaccination, including the relevance of genetics, trained innate immunity, and microbiome diversity.

Malaria and the incidence of COVID-19 in Africa: an ecological study

BACKGROUND

It has been shown that stimulation of innate immunity may provide temporary protection against a variety of infectious diseases. Malaria has been shown to induce a robust innate immune response. This study was conducted to test the hypothesis that if the cumulative number of cases diagnosed with COVID-19 per 100,000 population was correlated with the prevalence of malaria in African countries where both malaria and COVID-19 were prevalent.

METHODS

In this ecological study, the cumulative incidence of COVID-19 and the prevalence of malaria were compared in 53 African countries. A negative binomial regression analysis with the cumulative incidence of COVID-19 as the dependent variable, and the human development index (HDI) and the prevalence of malaria, as independent variables, were used.

RESULTS

The mean cumulative incidence of COVID-19 was 522 cases per 100,000. Each 0.1 unit increase in HDI was associated with 2.4-fold (95% confidence interval 1.8-3.1) increase in the cumulative incidence of COVID-19. Prevalence of malaria was also independently associated with the cumulative incidence; each 10% increase in the prevalence was associated with 28% (10-41%) decrease in the cumulative incidence of COVID-19.

CONCLUSIONS

Malaria might protect people against SARS-CoV-2 through the stimulation of innate immunity. Stimulation of the innate immune system could be the first line of defense in the pandemic preparedness arsenal.

One vaccine to counter many diseases? Modeling the economics of oral polio vaccine against child mortality and COVID-19

Introduction

Recent reviews summarize evidence that some vaccines have heterologous or non-specific effects (NSE), potentially offering protection against multiple pathogens. Numerous economic evaluations examine vaccines' pathogen-specific effects, but less than a handful focus on NSE. This paper addresses that gap by reporting economic evaluations of the NSE of oral polio vaccine (OPV) against under-five mortality and COVID-19.

Materials and methods

We studied two settings: (1) reducing child mortality in a high-mortality setting (Guinea-Bissau) and (2) preventing COVID-19 in India. In the former, the intervention involves three annual campaigns in which children receive OPV incremental to routine immunization. In the latter, a susceptible-exposed-infectious-recovered model was developed to estimate the population benefits of two scenarios, in which OPV would be co-administered alongside COVID-19 vaccines. Incremental cost-effectiveness and benefit-cost ratios were modeled for ranges of intervention effectiveness estimates to supplement the headline numbers and account for heterogeneity and uncertainty.

Results

For child mortality, headline cost-effectiveness was $650 per child death averted. For COVID-19, assuming OPV had 20% effectiveness, incremental cost per death averted was $23,000-65,000 if it were administered simultaneously with a COVID-19 vaccine <200 days into a wave of the epidemic. If the COVID-19 vaccine availability were delayed, the cost per averted death would decrease to $2600-6100. Estimated benefit-to-cost ratios vary but are consistently high.

Discussion

Economic evaluation suggests the potential of OPV to efficiently reduce child mortality in high mortality environments. Likewise, within a broad range of assumed effect sizes, OPV (or another vaccine with NSE) could play an economically attractive role against COVID-19 in countries facing COVID-19 vaccine delays.

Funding

The contribution by DTJ was supported through grants from Trond Mohn Foundation (BFS2019MT02) and Norad (RAF-18/0009) through the Bergen Center for Ethics and Priority Setting.

Ecosystems Determinants of Nutritional Adequacy Among the Indian Preschool Children

Given the specified importance of dietary diversity in reducing the burden of malnutrition, our study explores the reasons for the high rate of malnutrition in India through assessment of a comprehensive range of ecosystem factors leading to poor nutrients intake. The study uses the Dietary Diversity Score (DDS) to investigate preschoolers, through differences in wealth, gender, and health. Demographic and Health Survey (2015-16) data of 1,40,470 preschool children between the ages of 2-5 years, is investigated using the Bronfenbrenner's Ecological Systems Theory. Multiple linear regression models developed to investigate the association between variables, depict the importance of vaccination (p-value < 0.01, 95% CI 0.02-0.06) as positively impacting the outcome measures. Interestingly, overall wealth index does not impact the dietary diversity of the child. The lower wealth index, however, significantly impacts the DDS of the female child as compared to the male child (p-value < 0.1, 95% CI - 0.03 to 0.02), indicating that the lower wealth index plays a role in developing the non-egalitarian gender attitudes for female children. Policy implications involve adapting biofortified foods with higher density of nutrients with major focus on female children to minimize the gender gap and leveraging the digital technology such as telemedicine, and advanced techniques such as artificial intelligence, machine learning, and big data to offer real-time surveillance to address the healthcare needs in the ongoing immunization programs.

Supplementary Information

The online version contains supplementary material available at 10.1007/s41745-022-00339-4.

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.

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 &lt;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.

Vaccination With Oral Polio Vaccine Reduces COVID-19 Incidence

Background

Effective response to emerging pandemic threats is complicated by the need to develop specific vaccines and other medical products. The availability of broadly specific countermeasures that could be deployed early in the pandemic could significantly alter its course and save countless lives. Live attenuated vaccines (LAVs) were shown to induce non-specific protection against a broad spectrum of off-target pathogens by stimulating innate immune responses. The purpose of this study was to evaluate the effect of immunization with bivalent Oral Poliovirus Vaccine (bOPV) on the incidence of COVID-19 and other acute respiratory infections (ARIs).

Methods and Findings

A randomized parallel-group comparative study was conducted in Kirov Medical University. 1115 healthy volunteers aged 18 to 65 were randomized into two equal groups, one of which was immunized orally with a single dose of bOPV “BiVac Polio” and another with placebo. The study participants were monitored for three months for respiratory illnesses including COVID-19. The endpoint was the incidence of acute respiratory infections and laboratory confirmed COVID-19 in both groups during 3 months after immunization. The number of laboratory-confirmed cases of COVID-19 was significantly lower in the vaccinated group than in placebo (25 cases vs. 44, p=0.036). The difference between the overall number of clinically diagnosed respiratory illnesses in the two groups was not statistically significant.

Conclusions

Immunization with bOPV reduced the number of laboratory-confirmed COVID-19 cases, consistent with the original hypothesis that LAVs induce non-specific protection against off-target infections. The findings are in line with previous observations of the protective effects of OPV against seasonal influenza and other viral and bacterial pathogens. The absence of a statistically significant effect on the total number of ARIs may be due to the insufficient number of participants and heterogeneous etiology of ARIs. OPV could be used to complement specific coronavirus vaccines, especially in regions of the world where the vaccines are unavailable, and as a stopgap measure for urgent response to future emerging infections. Clinical trial registration number NCT05083039 at clinicaltrals.gov https://clinicaltrials.gov/ct2/show/NCT05083039?term=NCT05083039&draw=2&rank=1