Do Oral Cholera Vaccine and Water, Sanitation, and Hygiene Combine to Provide Greater Protection Against Cholera? Results From a Cluster-Randomized Trial of Oral Cholera Vaccine in Kolkata, India

Background

Oral cholera vaccine (OCV) and incremental improvements in household water, sanitation, and hygiene (WASH) within cholera-endemic areas can reduce cholera risk. However, we lack empiric evaluation of their combined impact.

Methods

We evaluated a cluster-randomized, placebo-controlled trial of OCV (Shanchol) in Kolkata, India. The study population included 108 777 individuals, and 106 879 nonpregnant individuals >1 year of age were eligible to receive 2 doses of OCV or placebo. We measured cholera risk in all household members assigned to OCV vs placebo and in all members of households with "Better" vs "Not Better" WASH, where WASH was classified according to validated criteria. Protection was measured by Cox proportional hazard models.

Results

Residence in an OCV household was associated with protective effectiveness (PE) of 54% (95% CI, 42%-64%; P < .001) and was similar regardless of Better (PE, 57%; 95% CI, 26%-75%; P = .002) or Not Better (PE, 53%; 95% CI, 40%-64%; P < .001) household WASH. Better WASH household residence was associated with PE of 30% (95% CI, 5%-48%; P = .023) and was similar in OCV (PE, 24%; 95% CI, -26% to 54%; P = .293) and placebo (PE, 29%; 95% CI, -3% to 51%; P = .069) households. When assessed conjointly, residence in OCV households with Better WASH was associated with the greatest PE against cholera at 69% (95% CI, 49%-81%; P < .001).

Conclusions

These findings suggest that the combination of a vaccine policy and improved WASH reduces cholera risk more than either would alone, although the magnitude of either intervention was not affected by the other. Future randomized trials investigating OCV and WASH interventions separately and together are recommended to further understand the interaction between OCV and WASH.

Association Among Household Water, Sanitation, and Hygiene (WASH) Status and Typhoid Risk in Urban Slums: Prospective Cohort Study in Bangladesh

BACKGROUND

Typhoid fever, or enteric fever, is a highly fatal infectious disease that affects over 9 million people worldwide each year, resulting in more than 110,000 deaths. Reduction in the burden of typhoid in low-income countries is crucial for public health and requires the implementation of feasible water, sanitation, and hygiene (WASH) interventions, especially in densely populated urban slums.

OBJECTIVE

In this study, conducted in Mirpur, Bangladesh, we aimed to assess the association between household WASH status and typhoid risk in a training subpopulation of a large prospective cohort (n=98,087), and to evaluate the performance of a machine learning algorithm in creating a composite WASH variable. Further, we investigated the protection associated with living in households with improved WASH facilities and in clusters with increasing prevalence of such facilities during a 2-year follow-up period.

METHODS

We used a machine learning algorithm to create a dichotomous composite variable ("Better" and "Not Better") based on 3 WASH variables: private toilet facility, safe drinking water source, and presence of water filter. The algorithm was trained using data from the training subpopulation and then validated in a distinct subpopulation (n=65,286) to assess its sensitivity and specificity. Cox regression models were used to evaluate the protective effect of living in "Better" WASH households and in clusters with increasing levels of "Better" WASH prevalence.

RESULTS

We found that residence in households with improved WASH facilities was associated with a 38% reduction in typhoid risk (adjusted hazard ratio=0.62, 95% CI 0.49-0.78; P<.001). This reduction was particularly pronounced in individuals younger than 10 years at the first census participation, with an adjusted hazard ratio of 0.49 (95% CI 0.36-0.66; P<.001). Furthermore, we observed an inverse relationship between the prevalence of "Better" WASH facilities in clusters and the incidence of typhoid, although this association was not statistically significant in the multivariable model. Specifically, the adjusted hazard of typhoid decreased by 0.996 (95% CI 0.986-1.006) for each percent increase in the prevalence of "Better" WASH in the cluster (P=.39).

CONCLUSIONS

Our findings demonstrate that existing variations in household WASH are associated with differences in the risk of typhoid in densely populated urban slums. This suggests that attainable improvements in WASH facilities can contribute to enhanced typhoid control, especially in settings where major infrastructural improvements are challenging. These findings underscore the importance of implementing and promoting comprehensive WASH interventions in low-income countries as a means to reduce the burden of typhoid and improve public health outcomes in vulnerable populations.

Better Existing Water, Sanitation, and Hygiene Can Reduce the Risk of Cholera in an Endemic Setting: Results From a Prospective Cohort Study From Kolkata, India

Background

Global cholera control efforts rely heavily on effective water, sanitation, and hygiene (WASH) interventions in cholera-endemic settings.

Methods

Using data from a large, randomized controlled trial of oral cholera vaccine conducted in Kolkata, India, we evaluated whether natural variations in WASH in an urban slum setting were predictive of cholera risk. From the control population (n = 55 086), baseline WASH data from a randomly selected "training subpopulation" (n = 27 634) were analyzed with recursive partitioning to develop a dichotomous ("better" vs "not better") composite household WASH variable from several WASH features collected at baseline, and this composite variable was then evaluated in a mutually exclusive "validation population" (n = 27 452). We then evaluated whether residents of better WASH households in the entire population (n = 55 086) experienced lower cholera risk using Cox regression models. Better WASH was defined by a combination of 4 dichotomized WASH characteristics including safe source of water for daily use, safe source of drinking water, private or shared flush toilet use, and always handwashing with soap after defecation.

Results

Residence in better WASH households was associated with a 30% reduction in risk of cholera over a 5-year period (adjusted hazard ratio, 0.70 [95% confidence interval, .49-.99]; P = .048). We also found that the impact of better WASH households on reducing cholera risk was greatest in young children (0-4 years) and this effect progressively declined with age.

Conclusions

The evidence suggests that modest improvements in WASH facilities and behaviors significantly modify cholera risk and may be an important component of cholera prevention and elimination strategies in endemic settings. Clinical Trials Registration. NCT00289224.

Comparing the effectiveness of bivalent and monovalent COVID-19 vaccines against COVID-19 infection during the winter season of 2022-2023: A real-world retrospective observational matched cohort study in the Republic of Korea

OBJECTIVES

To compare the effectiveness of bivalent and monovalent COVID-19 vaccines throughout the 2022-2023 winter season based on real-world data.

METHODS

This retrospective observational matched cohort study used the national vaccination program and a surveillance dataset from the Republic of Korea, and included adults aged >18 years who received bivalent or monovalent COVID-19 vaccines between October 11, 2022, and December 17, 2022. Cox proportional hazard models were used to estimate the hazard ratio for COVID-19 infection between the groups.

RESULTS

We included 29,245 matched individuals in the bivalent and monovalent vaccine groups, respectively. The bivalent vaccine recipients showed 12.2% (95% confidence interval [CI] 6.5-17.7%) additional protection against COVID-19 infection compared with the monovalent vaccine recipients. The additional protection provided by bivalent vaccines was significantly higher among residents of long-term care facilities (39.4%, 95% CI 21.6-53.1%). Maximum additional protection was observed 3 to 4 months after completing the vaccination (17.6%, 95% CI 6.6-27.3%).

CONCLUSION

Bivalent COVID-19 vaccines showed significantly better protection against infection than monovalent vaccines among adults during the 2022-2023 winter season. Our results highlight that immunization programs with bivalent vaccines comprising recent variants can be an effective measure to prepare for seasonal COVID-19 circulation.

Poliovirus type 1 systemic humoral and intestinal mucosal immunity induced by monovalent oral poliovirus vaccine, fractional inactivated poliovirus vaccine, and bivalent oral poliovirus vaccine: A randomized controlled trial

BACKGROUND

To inform response strategies, we examined type 1 humoral and intestinal immunity induced by 1) one fractional inactivated poliovirus vaccine (fIPV) dose given with monovalent oral poliovirus vaccine (mOPV1), and 2) mOPV1 versus bivalent OPV (bOPV).

METHODS

We conducted a randomized, controlled, open-label trial in Dhaka, Bangladesh. Healthy infants aged 5 weeks were block randomized to one of four arms: mOPV1 at age 6-10-14 weeks/fIPV at 6 weeks (A); mOPV1 at 6-10-14 weeks/fIPV at 10 weeks (B); mOPV1 at 6-10-14 weeks (C); and bOPV at 6-10-14 weeks (D). Immune response at 10 weeks and cumulative response at 14 weeks was assessed among the modified intention-to-treat population, defined as seroconversion from seronegative (<1:8 titers) to seropositive (≥1:8) or a four-fold titer rise among seropositive participants sustained to age 18 weeks. We examined virus shedding after two doses of mOPV1 with and without fIPV, and after the first mOPV1 or bOPV dose. The trial is registered at ClinicalTrials.gov (NCT03722004).

FINDINGS

During 18 December 2018 - 23 November 2019, 1,192 infants were enrolled (arms A:301; B:295; C:298; D:298). Immune responses at 14 weeks did not differ after two mOPV1 doses alone (94% [95% CI: 91-97%]) versus two mOPV1 doses with fIPV at 6 weeks (96% [93-98%]) or 10 weeks (96% [93-98%]). Participants who received mOPV1 and fIPV at 10 weeks had significantly lower shedding (p < 0·001) one- and two-weeks later compared with mOPV1 alone. Response to one mOPV1 dose was significantly higher than one bOPV dose (79% versus 67%; p < 0·001) and shedding two-weeks later was significantly higher after mOPV1 (76% versus 56%; p < 0·001) indicating improved vaccine replication. Ninety-nine adverse events were reported, 29 serious including two deaths; none were attributed to study vaccines.

INTERPRETATION

Given with the second mOPV1 dose, fIPV improved intestinal immunity but not humoral immunity. One mOPV1 dose induced higher humoral and intestinal immunity than bOPV.

FUNDING

U.S. Centers for Disease Control and Prevention.

The interplay between WASH practices and vaccination with oral cholera vaccines in protecting against cholera in urban Bangladesh: Reanalysis of a cluster-randomized trial

The current global initiative to end Cholera by 2030 emphasizes the use of oral cholera vaccine (OCV) combined with feasible household Water-Sanitation-Hygiene (WASH) interventions. However, little is known about how improved WASH practices and behaviors and OCV interact to reduce the risk of cholera. We reanalyzed two arms of a cluster-randomized trial in urban Bangladesh, to evaluate the effectiveness of OCV given as a 2-dose regimen. One arm (30 clusters, n = 94,675) was randomized to vaccination of persons aged one year and older with OCV, and the other arm (30 clusters, n = 80,056) to no intervention. We evaluated the prevention of cholera by household WASH, classified at baseline using a previously validated rule, and OCV over 2 years of follow-up. When analyzed by assignment to OCV clusters rather than receipt of OCV, in comparison to persons living in "Not Better WASH" households in the control clusters, reduction of severe cholera (the primary outcome) was similar for persons in "Not Better WASH" households in vaccine clusters (46%, 95% CI:24,62), for persons in "Better WASH" households in the control clusters (48%, 95% CI:25,64), and for persons in "Better WASH" households in the vaccine clusters (48%, 95% CI:16,67). In contrast, when analyzed by actual receipt of a complete OCV regimen, , in comparison to persons in "Not Better WASH" households in the control clusters, protection against severe cholera increased steadily from 39% (95% CI:13,58) in residents of "Better WASH" households in the control clusters to 57% (95% CI:35,72) in vaccinated persons in "Not Better WASH" households to 63% (95% CI:21,83) in vaccinated persons in "Better WASH" households. This analysis suggests that improved household WASH and OCV received may interact to provide greater protection against cholera. However, the divergence between findings related to intent to vaccinate versus those pertaining to actual receipt of OCV underscores the need for further research on this topic.

Hepatitis E Virus (HEV) Synopsis: General Aspects and Focus on Bangladesh

HEV is the most common cause of acute hepatitis globally. This review summarizes the latest knowledge on the epidemiology, clinical characteristics, testing, and treatment of HEV infection. We also focused on Bangladesh to highlight the distinct challenges and the possible remedies. In low-income settings, the virus is mainly transmitted between people by fecal contamination of drinking water causing large outbreaks, and sporadic cases. The disease is usually mild and self-limiting acute hepatitis. Still, pregnant women and their offspring in low-income countries are at particular risk for severe disease, with up to 20% maternal mortality. Despite the high burden of the disease, HEV remains a relatively neglected virus, with detection hampered by costly tests and a lack of suitable treatments. Molecular PCR diagnostics, together with ELISA antibody tests, remain the preferred methods for diagnosis of HEV; however, rapid bedside diagnostics are available and could offer a practical alternative, especially in low-income countries. One vaccine (HEV 239) is only available in China and Pakistan, as efficacy against the other genotypes remains uncertain. The effectiveness trial conducted in Bangladesh might lead the way in gathering more efficacy data and could, together with improved surveillance and raised awareness, dramatically reduce the global burden of HEV.

Cost of oral cholera vaccine delivery in a mass immunization program for children in urban Bangladesh

Cholera poses a substantial health burden in the developing world due to both epidemic and endemic diseases. The World Health Organization recommends oral cholera vaccines for mass vaccination campaigns in addition to traditional prevention practices and treatments in resource-poor settings. In many developing countries like Bangladesh, the major challenge behind implementing mass vaccination campaigns concerns the affordability of the oral cholera vaccine (OCV). Vaccination of children with OCV is not only an impactful approach for controlling cholera at the population level and reducing childhood morbidity but is also considered more cost-effective than vaccinating all ages. The aim of the study was to estimate the cost of an OCV campaign for children from a societal perspective using empirical study. A total of 66,311 children aged 1 to 14 years old were fully vaccinated with two doses of the OCV Shanchol while 9,035 individuals received one dose of this vaccine. The estimated societal cost per individual for full vaccination was US$ 6.11, which includes the cost of vaccine delivery estimated at US$ 1.95. The cost per single dose was estimated at US$ 2.86. The total provider cost for full vaccination was estimated at US$ 6.01 and the recipient cost at US$ 0.10. Our estimation of OCV delivery costs for children was relatively higher than what was found in a similar mass OCV campaign for all age groups, indicating that there may be additional cost factors to consider in targeted vaccine campaigns. This analysis provides useful benchmarks for the possible costs related to delivery of OCV to children and future OCV cost-effectiveness models should factor in these possible cost disparities. Attempts to reduce the cost per dose are likely to have a greater impact on the cost of similar vaccination campaigns in many resource-poor settings.

Impact of vaccination with SCB-2019 COVID-19 vaccine on transmission of SARS-CoV-2 infection: a household contact study in the Philippines

Background

An exploratory household transmission study was nested in SPECTRA, the phase 2/3 efficacy study of the adjuvanted recombinant protein-based COVID-19 vaccine SCB-2019. We compared occurrence of confirmed COVID-19 infections between households and household contacts of infected SPECTRA placebo or SCB-2019 recipients.

Methods

SPECTRA participants at eight study sites in the Philippines who developed rRT-PCR-confirmed COVID-19 were contacted by a study team blinded to assignment of index cases to vaccine or placebo groups to enroll in this household transmission study. Enrolled households and household contacts were monitored for three weeks using rRT-PCR and anti-SARS-CoV-2 N-antigen IgG/IgM testing to detect new COVID-19 infections.

Results

154 eligible COVID-19 index cases (51 vaccinees, 103 placebo) were included. The secondary attack rate per household for symptomatic COVID-19 infection was 0.76% (90% CI: 0.15–3.90) if the index case was a SCB-2019 vaccinee compared with 5.88% (90% CI: 3.20–10.8) for placebo index cases, a relative risk reduction (RRR) of 79% (90% CI: -28–97). The RRR of symptomatic COVID-19 per household member was similar: 84% (90% CI: 28–97). Impact on attack rates in household members if index cases were symptomatic (n = 130; RRR = 80%; 90% CI: 7–96) or asymptomatic (n = 24; RRR = 100%; 90% CI: -76–100) was measurable but the low numbers undermine the clinical significance.

Conclusions

In this prospective household contact study vaccination with SCB-2019 reduced SARS-CoV-2 transmission compared with placebo in households and in household members independently of whether index cases were symptomatic or not.

Are better existing WASH practices in urban slums associated with a lower long-term risk of severe cholera? A prospective cohort study with 4 years of follow-up in Mirpur, Bangladesh

OBJECTIVE

To investigate the association between existing household water quality, sanitation and hygiene (WASH) practices and severe cholera risk in a dense urban slum where cholera is highly endemic.

DESIGN, SETTING AND PARTICIPANTS

We assembled a large prospective cohort within a cluster randomised trial evaluating the effectiveness of oral cholera vaccine. Our dynamic cohort population (n=193 576) comprised individuals living in the 'non-intervention' clusters of the trial, and were followed over 4 years. This study was conducted in a dense urban slum community of Dhaka, Bangladesh and cholera surveillance was undertaken in 12 hospitals serving the study area.

PRIMARY OUTCOME MEASURE

First severe cholera episode detected during follow-up period.

METHODS

We applied a machine learning algorithm on a training subpopulation (n=96 943) to develop a binary ('better', 'not better') composite WASH variable predictive of severe cholera. The WASH rule was evaluated for performance in a separate validation subpopulation (n=96 633). Afterwards, we used Cox regression models to evaluate the association between 'better' WASH households and severe cholera risk over 4 years in the entire study population.

RESULTS

The 'better' WASH rule found that water quality and access were the most significant factors associated with severe cholera risk. Members of 'better' WASH households, constituting one-third of the population, had a 47% reduced risk of severe cholera (95% CI: 29 to 69; p<0.001), after adjusting for covariates. The protective association between living in a 'better' WASH household and severe cholera persisted in all age groups.

CONCLUSIONS

Salutary existing household WASH practices were associated with a significantly reduced long-term risk of severe cholera in an urban slum of Dhaka. These findings suggest that WASH adaptations already practised in the community may be important for developing and implementing effective and sustainable cholera control programmes in similar settings.

TRIAL REGISTRATION NUMBER

This article is a re-analysis of data from a cluster randomized trial; can be found on ClinicalTrials.gov NCT01339845.

Prevention of typhoid by Vi conjugate vaccine and achievable improvements in household WASH: Evidence from a cluster-randomized trial in Dhaka, Bangladesh

BACKGROUND

Typhoid fever contributes to approximately 135,000 deaths annually. Achievable improvements in household water-hygiene-sanitation (WASH) combined with vaccination using typhoid conjugate vaccines (TCVs) may be an effective preventive strategy. However, little is known about how improved WASH and vaccination interact to lower the risk of typhoid.

METHODS

61,654 urban Bangladeshi children aged 9 months to <16 years, residing in 150 clusters with a baseline population of 205,760 residents, were randomized 1: 1 by cluster to Vi-tetanus toxoid TCV or Japanese Encephalitis (JE) vaccine. Surveillance for blood culture-confirmed typhoid fever was conducted over two years. Existing household WASH status was assessed at baseline as Better or Not Better using previously validated criteria. The reduction in typhoid risk among all residents associated with living in TCV clusters, Better WASH households, or both was evaluated using mixed-effects Poisson regression models.

RESULTS

The adjusted reduced risk of typhoid among all residents living in the clusters assigned to TCV was 55% (95% confidence interval (CI): 43%,65%; p < 0.001), and that of living in Better WASH households, regardless of cluster, was 37% (95%CI: 24%,48%; p < 0.001). The highest risk of typhoid was observed in persons living in households with Not Better WASH in the JE clusters. In comparison with these persons, those living in households with Better WASH in the TCV clusters had an adjusted reduced risk of 71% (95%CI: 59%, 80%; p < 0.001).

CONCLUSION

Implementation of TCV programs combined with achievable and culturally acceptable household WASH practices were independently associated with a significant reduction in typhoid risk.

Perceptions about Telemedicine among Populations with Chronic Diseases amid COVID-19: Data from a Cross-Sectional Survey

Chronic diseases, including non-communicable diseases (NCDs), have arisen as a severe threat to health and socio-economic growth. Telemedicine can provide both the highest level of patient satisfaction and the lowest risk of infection during a pandemic. The factors associated with its usage and patient adherence are not visible in Bangladesh’s resource-constrained settings. Therefore, this study aimed to identify perceptions about telemedicine among populations with chronic diseases amid the COVID-19 pandemic. A closed-ended self-reported questionnaire was created, and the questionnaire was written, reviewed, and finalized by a public health investigator, a psychiatrist, and an epidemiologist. The data for this study were collected from individuals using simple random sampling and snowball sampling techniques. Ethics approval was granted, and written/verbal consent was taken before interviews. Most of the participants showed a positive attitude towards telemedicine. People aged 35–54 years old and a higher level of education were less frequently associated with willingness to receive telemedicine services for current chronic disease (WRTCCD) than their counterparts. People living in urban areas and lower-income participants were more strongly associated with WRTCCD. Additionally, people who did not lose their earnings due to the pandemic were less strongly associated with WRTCCD. However, the main strength of this research is that it is a broad exploration of patient interest in several general forms of telehealth. In Bangladesh, there are many opportunities for telemedicine to be integrated into the existing healthcare system, if appropriate training and education are provided for healthcare professionals.

Prevention of Typhoid Fever by Existing Improvements in Household Water, Sanitation, and Hygiene, and the Use of the Vi Polysaccharide Typhoid Vaccine in Poor Urban Slums: Results from a Cluster-Randomized Trial

Modest improvements in household water, sanitation, and hygiene (WASH) and typhoid vaccination can reduce typhoid risk in endemic settings. However, empiric evaluation of their combined impact is lacking. A total of 62,756 persons residing in 80 clusters in a Kolkata slum were allocated randomly 1:1 to either the typhoid Vi polysaccharide (ViPS) vaccine or hepatitis A (Hep A) vaccine. Surveillance was conducted for 2 years before and 2 years after vaccination. We classified households as having "better" or "not better" WASH, and calculated the prevalence of better WASH households in clusters using previously validated criteria. We evaluated the protection by better household WASH, better household WASH prevalence, and ViPS vaccination against typhoid in all cluster members present at baseline using Cox proportional hazard models. Overall, ViPS vaccination was associated with a 55% (P < 0.001; 95% CI, 35-69) reduction of typhoid risk and was similar regardless of better WASH in the residence. Living in a better WASH household was associated with a typhoid risk reduction of 31% (P = 0.16; 95% CI, -16 to 59) overall. The reduction was 48% (P = 0.05; 95% CI, -1 to 73) in Hep A clusters, 6% (P = 0.85; 95% CI, -82 to 51) in ViPS clusters, and 57% (P < 0.05; 95% CI, 15-78) in the population during the 2 years preceding the trial. These findings demonstrate a preventive association of better household WASH in the non-ViPS population, but, unexpectedly, an absence of additional protection from ViPS by better WASH in the ViPS population. This analysis highlights the importance of assessing the combination of WASH in conjunction with typhoid vaccines, and has implications for the evaluation of new-generation typhoid conjugate vaccines.

Evaluation of protection by COVID-19 vaccines after deployment in low and lower-middle income countries

The availability and use of vaccines for the coronavirus disease 2019 (COVID-19) in low and middle-income countries (L/MICs) lags far behind more affluent countries, and vaccines currently used in L/MICs are predominantly of lower efficacy. As vaccines continue to be rolled out in L/MICs, successful control of COVID-19 by vaccines requires monitoring both of vaccine protection of vaccinees (effectiveness) and of the entire targeted populations, including vaccine herd protection of non-vaccinees (impact). To be of greatest relevance to L/MICs, there is the need to address the distinctive medical and demographic features of populations, health systems, and demography that may greatly affect vaccine performance in these settings. We identified 58 published studies that included 85 evaluations of the effectiveness of different COVID-19 vaccines globally. Only three were done in L/MICs, and no impact studies were identified in these settings. Post-deployment studies of the protection by COVID-19 vaccines rolled out in L/MICs constitute an important but currently neglected global priority.

A five-day course of ivermectin for the treatment of COVID-19 may reduce the duration of illness

Ivermectin, a US Food and Drug Administration-approved anti-parasitic agent, was found to inhibit severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) replication in vitro. A randomized, double-blind, placebo-controlled trial was conducted to determine the rapidity of viral clearance and safety of ivermectin among adult SARS-CoV-2 patients. The trial included 72 hospitalized patients in Dhaka, Bangladesh, who were assigned to one of three groups: oral ivermectin alone (12 mg once daily for 5 days), oral ivermectin in combination with doxycycline (12 mg ivermectin single dose and 200 mg doxycycline on day 1, followed by 100 mg every 12 h for the next 4 days), and a placebo control group. Clinical symptoms of fever, cough, and sore throat were comparable among the three groups. Virological clearance was earlier in the 5-day ivermectin treatment arm when compared to the placebo group (9.7 days vs 12.7 days; p = 0.02), but this was not the case for the ivermectin + doxycycline arm (11.5 days; p = 0.27). There were no severe adverse drug events recorded in the study. A 5-day course of ivermectin was found to be safe and effective in treating adult patients with mild COVID-19. Larger trials will be needed to confirm these preliminary findings.

Debate on Bacille Calmette-Guérin vaccination against COVID-19: Is it worth performing clinical trials?

The non-specific beneficial effects of Bacille Calmette-Guérin (BCG) vaccination suggest that this vaccine might play a role in protecting individuals against severe coronavirus disease 2019 (COVID-19). Several studies propose that BCG vaccination may increase the body's immunity, thereby preventing respiratory infections caused by other respiratory pathogens. As the number of deaths due to COVID-19 is increasing rapidly and there is no specific treatment available to date, scientists are evaluating the effectiveness of already approved drugs as therapies against COVID-19, and the results were found to vary widely: from no significant effect being observed to a reduction in the time taken for clinical improvement. This study thus aims to evaluate whether it is worth performing clinical trials to examine the effects of the BCG vaccine on COVID-19. We herein emphasize the need to conduct phase III randomized controlled trials with adequate sample size and quality to investigate the effects of the BCG vaccine on COVID-19. In the event that BCG vaccination provides non-specific protection against COVID-19, administering it could be helpful in controlling the transmission of COVID-19 and other infectious diseases during future pandemics.

A randomized Phase I/II study to evaluate safety and reactogenicity of a heat-stable rotavirus vaccine in healthy adults followed by evaluation of the safety, reactogenicity, and immunogenicity in infants

Objectives: To assess the safety and reactogenicity of single oral dose of heat-stable rotavirus vaccine (HSRV) in healthy adults aged 18–45 years followed by assessment of safety, reactogenicity, and immunogenicity of three doses of HSRV in healthy infants aged 6–8 weeks at enrollment.

Trial Design: Single-center randomized controlled, sequential, blinded (adults) and open-label (infants).

Setting: Single site at International Center for Diarrheal Disease Research, Bangladesh (icddr,b).

Participants: Fifty eligible adults randomized in 1:1 ratio (HSRV: Placebo) followed by 50 eligible infants randomized in 1:1 ratio (HSRV: Comparator (RotaTeq®, pentavalent human-bovine (WC3) reassortant live-attenuated, rotavirus vaccine)).

Intervention: Adults received either a single dose of HSRV or placebo and followed for 14 days. Infants received three doses of either HSRV or comparator with a follow-up for 28 days after each dose.

Main Outcome Measures: Solicited and unsolicited adverse events (AEs) along with any serious adverse events (SAEs) were part of the safety and reactogenicity assessment in adults and infants whereas serum anti-rotavirus IgA response rates were part of immunogenicity assessment in infants only. Post-vaccination fecal shedding of vaccine-virus rotavirus strains was also determined in adults and infants.

Results: In this study, HSRV, when compared with placebo, did not result in increase in solicited adverse events (solicited AEs) in adults. In infants, HSRV had a safety profile similar to comparator vis-à-vis solicited AEs. In infants, fecal shedding of vaccine-virus strains was not detected in HSRV recipients but was observed in two comparator recipients. Percentage of infants exhibiting threefold rise in serum anti-rotavirus IgA titers from baseline to 1-month post-dose 3 in HSRV group was 88% (22/25) and 84% (21/25) in comparator group.

Conclusion: HSRV was found to be generally well-tolerated in both adults and infants and immunogenic in infants.

Impact of vaccination on the risk factors for acute rotavirus diarrhea: An analysis of the data of a cluster randomized trial conducted in a rural area of Bangladesh

BACKGROUND

Rotavirus is one of the causes of severe diarrhea and death in young children. To control the disease, safe and effective vaccines are being used in several countries. We assessed the impact of vaccination on the risk factors for acute rotavirus diarrhea (ARD) in Bangladesh.

METHODS

We used the data of a cluster-randomized trial. The clusters were 142 villages, 71 in each of the two arms of study. The infants were offered human rotavirus vaccine (HRV), Rotarix, over three-year period. We divided the time period into two equal periods (T1 and T2). A generalized estimating equation with logit-link function was used to evaluate the risk factors by arm and by period.

RESULTS

Among 10,917 children, 5,759 (53%) were in the HRV villages. We had 359 cases; 44% in the HRV villages. Mean age of attack was similar between the arms of study in T1, but significantly higher in HRV villages than that in the non-HRV villages in T2. In HRV villages, males were at a higher risk of having ARD than females in T1, but not in T2. In contrast, males were at a higher risk of having ARD in both the time periods in non-HRV villages. In HRV-villages, children having literate mother were at significantly higher risk of having ARD in T1 but not in T2; whereas children in the non-HRV villages had a higher risk of having ARD in T2. Children living in an area with higher phone users had more cases than their counterpart in non-HRV villages, but not in HRV villages.

CONCLUSION

Our study illustrates that several risk factors for ARD varied between the two arms of study as well as between the two periods of study. Assessing post-vaccination risk factors is, therefore, important for understanding the impact of vaccination and undertaking post-vaccination control measures.

Prevalence and severity of viral hepatitis in Pakistani pregnant women: a five year hospital based study

A hospital based observational study was carried out on pregnant women presenting with either acute hepatitis or fulminant hepatic failure (FHF), during the past years. Of 53 patients, 20 (38%) developed FHF.Non-A, Non-B was the commonest cause (62%) followed by hepatitis B in 17% and hepatitis A in 4% cases. Eight women expired (case fatality rate 15%) with a high maternal mortality (62%) caused by NANB hepatitis. Perinatal mortality was 30%. Poor prognostic factors identified were lack of antenatal care, severity of jaundice, history of somnolence, gastrointestinal bleeding and a high grade of encephalopathy.

Inhibitors of Deuterophoma tracheiphila in Citrus Varieties Resistant to "Mal Secco"

Growth of colonies of the fungus Deuterophoma tracheiphila, the causal agent of the "mal secco" disease of lemons, is inhibited by two substances, C(1) and CS(2), which are found in resistant mandarin varieties but not in susceptible lemons and related species. Some properties of these substances are reported. CS(2) may be naringenin, but the stronger inhibitor, C(1), has not yet been identified.