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The World Health Organization (WHO) African Region has approximately 100 million people with chronic hepatitis B virus (HBV) infection. This review describes the status of hepatitis B control in the Region. We present hepatitis B vaccine (HepB) coverage data and from available data in the published literature, the impact of HepB vaccination on hepatitis B surface antigen (HBsAg) prevalence, a marker of chronic infection, among children, HBsAg prevalence in pregnant women, and risk of perinatal transmission. Lastly, we describe challenges with HepB birth dose (HepB-BD) introduction reported in the Region, and propose strategies to increase coverage. In 2015, regional three dose HepB coverage was 76%, and 16(34%) of 47 countries reported ≥ 90% coverage. Overall, 11 countries introduced HepB-BD; only nine provide universal HepB-BD, and of these, five reported ≥ 80% coverage. From non-nationally representative serosurveys among children, HBsAg prevalence was lower among children born after HepB introduction compared to those born before HepB introduction. However, some studies still found HBsAg prevalence to be above 2%. From limited surveys among pregnant women, the median HBsAg prevalence varied by country, ranging from 1.9% (Madagascar) to 16.1% (Niger); hepatitis B e antigen (HBeAg) prevalence among HBsAg-positive women ranged from 3.3% (Zimbabwe) to 28.5% (Nigeria). Studies in three countries indicated that the risk of perinatal HBV transmission was associated with HBeAg expression or high HBV DNA viral load. Major challenges for timely HepB-BD administration were poor knowledge of or lack of national HepB-BD vaccination guidelines, high prevalence of home births, and unreliable vaccine supply. Overall, substantial progress has been made in the region. However, countries need to improve HepB3 coverage and some countries might need to consider introducing the HepB-BD to help achieve the regional hepatitis B control goal of < 2% HBsAg prevalence among children < 5 years old by 2020. To facilitate HepB-BD introduction and improve timely coverage, strategies are needed to reach both facility-based and home births. Strong political commitment, clear policy recommendations and staff training on HepB-BD administration are also required. Furthermore, high quality nationally representative serosurveys among children are needed to inform decision makers about progress towards the regional control goal.

In 2016, the Immunization Technical Advisory Group of the South-East Asia Region (SEAR) endorsed a regional goal to achieve ≤1% prevalence of hepatitis B surface antigen (HBsAg) among 5-year-old children by 2020. Chronic hepatitis B virus (HBV) infection is largely preventable with a birth dose of hepatitis B vaccine (HepB-BD) followed by two to three additional doses. We reviewed the progress towards hepatitis B control through vaccination in SEAR during 1992-2015. We summarized hepatitis B vaccination data and reviewed the literature to determine the prevalence of chronic HBV infection pre- and post-vaccine introduction. We used a mathematical model to determine post-vaccine prevalence of HBsAg among 5 year olds in countries lacking national serosurvey data and estimated the impact of vaccination on disease burden. Regional coverage with three doses of hepatitis B vaccine (HepB3) increased from 56% in 2011 to 87% in 2015. By 2016, 7 of 11 countries had introduced universal HepB-BD. Regional HepB-BD coverage increased from 9% in 2011 to 34% in 2015. In 2015, estimated HBsAg among 5 year olds was 1.1% with variability among countries. Myanmar (3.8%), Timor-Leste (2.7%), Indonesia (1.8%), and India (1%) had the highest prevalence of HBsAg. During 1992-2015, vaccination prevented approximately 16 million chronic HBV infections and 2.6 million related deaths. In 2015, around 197,640 perinatal HBV infections occurred in SEAR with majority occurring in India (62%), Bangladesh (24%), and Myanmar (8%). Myanmar had the highest rate of perinatal chronic HBV infections at 16 per 1000 live births. Despite significant progress in the control of HBV, SEAR needs to secure political commitment for elimination and consider additional strategies, such as promoting health facility births, universal birth dose administration, developing strong coordination between health sectors, and using alternative vaccine delivery methods, to improve HepB-BD coverage and subsequently achieve HBV control and elimination.

In 2013, the Government of Haiti implemented its first oral cholera vaccine (OCV) campaign in Petite Anse, an urban setting, and Cerca Carvajal, a rural commune. We conducted and compared responses to two independent cross-sectional knowledge and practices household surveys pre- (N = 297) and post- (N = 302) OCV campaign in Petite Anse. No significant differences in knowledge about causes, symptoms, and prevention of cholera were noted. Compared with precampaign respondents, fewer postcampaign respondents reported treating (66% versus 27%, P < 0.001) and covering (96% versus 89%, P = 0.02) their drinking water. Compared with precampaign, postcampaign survey household observations showed increased availability of soap (16.2% versus 34.5%, P = 0.001) and handwashing stations (14.7% versus 30.1%, P = 0.01), but no significant changes in handwashing practices were reported. Although there was no change in knowledge, significant decreases in water treatment practices necessary for cholera and other diarrheal diseases prevention were noted in the postcampaign survey. Future OCV campaigns in Haiti should be used as an opportunity to emphasize the importance of maintaining good water, sanitation, and hygiene practices, and include a comprehensive, integrated approach for cholera control.

In 2016, the World Health Assembly endorsed the Global Health Sector Strategy on Viral Hepatitis, which calls for elimination of hepatitis B virus (HBV) by 2030 (definition: £ 0.1% hepatitis B surface antigen [HBsAg] prevalence among children aged 5 years). The burden of chronic HBV infection among children in Haiti is unknown. We conducted a nationally representative cross-sectional serological survey among 5-to 7-year-old children based on a two-stage cluster design with two strata: West (includes metropolitan Port-au-Prince) and non-West (all other departments). We collected demographic, socioeconomic, and vaccination history data and tested for HBsAg using a rapid point-of-care test. We estimated HBsAg prevalence and evaluated the association of HBV infection with vaccination history, demographics, and socioeconomic characteristics.

In Haiti, measles, rubella, and maternal and neonatal tetanus have been eliminated, but a diphtheria outbreak is ongoing as of 2019. We conducted a nationally representative, household-based, two-stage cluster survey among children aged 5-7 years in 2017 to assess progress toward maintenance of control and elimination of selected vaccine-preventable diseases (VPDs). We stratified Haiti into West region (West department, including the capital city) and non-West region (all other departments). We obtained vaccination history and dried blood spots, and measured antibody concentrations to VPDs on a multiplex bead assay. Among 1,146 children, national seropositivity was 83% (95% CI: 80-86%) for tetanus, 83% (95% CI: 81-85%) for diphtheria, 87% (95% CI: 85-89%) for measles, and 84% (95% CI: 81-87%) for rubella. None of the children had long-term immunity to tetanus or diphtheria (IgG concentration ³ 1 international unit/mL). Seropositivity in the West region was lower than that in the non-West region. Vaccination coverage was 68% (95% CI: 61-74%) for ³ 3 doses of tetanus-and diphtheria-containing vaccine (DTP3), 84% (95% CI: 80-87%) for one dose of measles-rubella vaccine (MR1), and 20% (95% CI: 16-24%) for MR2. The seroprevalence of measles, rubella, and diphtheria antibodies is lower than population immunity levels needed to prevent disease transmission, particularly in the West region; reintroduction of these diseases could lead to an outbreak. To maintain VPD control and elimination, Haiti should achieve DTP3 and MR2 coverage ³ 95%, and include tetanus and diphtheria booster doses in the routine immunization schedule.

Hepatitis E virus (HEV) infection is associated with a high fatality rate among pregnant women, and gestational complications have been reported among pregnant women infected with hepatitis A virus (HAV). The aim of this study was to determine the seroprevalence of HAV and HEV infections among pregnant women in Haiti. We stratified the population (n = 1,307) between West and non-West regions. Specimens were tested for total HAV antibody (anti-HAV), and IgM and IgG HEV antibody (anti-HEV). Overall, 96.8% pregnant women were positive for total anti-HAV, 10.3% for IgG anti-HEV, and 0.3% for IgM anti-HEV. The prevalence of IgG anti-HEV in the non-West region (12.3%) was significantly greater than that in the West region (5.3%) (P < 0.0001). Most pregnant women in Haiti had evidence of past exposure and immunity to HAV. The non-West region had a higher prevalence of HEV. Improvement in water and sanitation will help in the prevention and control of these infections in Haiti.

New pneumococcal conjugate vaccines (PCVs), 15- and 20-valent (PCV15 and PCV20), have been licensed for use among U.S. adults based on safety and immunogenicity data compared with the previously recommended 13-valent PCV (PCV13) and 23-valent pneumococcal polysaccharide vaccines (PPSV23). We conducted a systematic review of the literature on PCV13 and PPSV23 efficacy (randomized controlled trials [RCTs]) or effectiveness (observational studies) against vaccine type (PCV13 type or PPSV23 type, respectively), invasive pneumococcal disease (IPD), and pneumococcal pneumonia (PP) in adults. We utilized the search strategy from a previous systematic review of the literature published during the period from January 2016 to April 2019, and updated the search through March 2022. The certainty of evidence was assessed using the Cochrane risk-of-bias 2.0 tool and the Newcastle–Ottawa scale. When feasible, meta-analyses were conducted. Of the 5085 titles identified, 19 studies were included. One RCT reported PCV13 efficacy of 75% (PCV13-type IPD) and 45% (PCV13-type PP). Three studies each reported PCV13 effectiveness against PCV13-type IPD (range 47% to 68%) and against PCV13-type PP (range 38% to 68%). The pooled PPSV23 effectiveness was 45% (95% CI: 37%, 51%) against PPSV23-type IPD (nine studies) and 18% (95% CI: −4%, 35%) against PPSV23-type PP (five studies). Despite the heterogeneity across studies, our findings suggest that PCV13 and PPSV23 protect against VT-IPD and VT-PP in adults.