Post introduction evaluation of the malaria vaccine implementation programme in Ghana, 2021.

BACKGROUND: Malaria remains a public health challenge in Sub-Saharan Africa with the region contributing to more than 90% of global cases in 2020. In Ghana, the malaria vaccine was piloted to assess the feasibility, safety, and its impact in the context of routine use alongside the existing recommended malaria control measures. To obtain context-specific evidence that could inform future strategies of introducing new vaccines, a standardized post-introduction evaluation (PIE) of the successes and challenges of the malaria vaccine implementation programme (MVIP) was conducted. METHODS: From September to December 2021, the WHO Post-Introduction Evaluation (PIE) tool was used to conduct a mixed methods evaluation of the MVIP in Ghana. To ensure representativeness, study sites and participants from the national level, 18 vaccinating districts, and 54 facilities from six of the seven pilot regions were purposively selected. Quantitative and qualitative data were collected using data collection tools that were adapted based on the WHO PIE protocol. We performed summary descriptive statistics on quantitative data, thematic analysis on qualitative data, and triangulation of the results from both sets of analyses. RESULTS: About 90.7% (49/54) of health workers stated that the vaccine introduction process was smooth and contributed to an overall improvement of routine immunisation services. About 87.5% (47/54) of healthcare workers, and 95.8% (90/94) of caregivers accepted RTS,S malaria vaccine. Less than half [46.3%; (25/54)] of the healthcare workers participated in the pre-vaccine introduction training but almost all [94.4%; (51/54)] were able to constitute and administer the vaccine appropriately. About 92.5% (87/94) of caregivers were aware of the RTS,S introduction but only 44.0% (44/94) knew the number of doses needed for maximum protection. Health workers believed that the MVIP has had a positive impact on under five malaria morbidity. CONCLUSIONS: The malaria vaccine has been piloted successfully in Ghana. Intensive advocacy; community engagement, and social mobilization; and regular onsite supportive supervision are critical enablers for successful introduction of new vaccines. Stakeholders are convinced of the feasibility of a nationwide scale up using a phased subnational approach taking into consideration malaria epidemiology and global availability of vaccines.

Longitudinal estimation of Plasmodium falciparum prevalence in relation to malaria prevention measures in six sub-Saharan African countries.

BACKGROUND: Plasmodium falciparum prevalence (PfPR) is a widely used metric for assessing malaria transmission intensity. This study was carried out concurrently with the RTS,S/AS01 candidate malaria vaccine Phase III trial and estimated PfPR over ≤ 4 standardized cross-sectional surveys. METHODS: This epidemiology study (NCT01190202) was conducted in 8 sites from 6 countries (Burkina Faso, Gabon, Ghana, Kenya, Malawi, and Tanzania), between March 2011 and December 2013. Participants were enrolled in a 2:1:1 ratio according to age category: 6 months-4 years, 5-19 years, and ≥ 20 years, respectively, per year and per centre. All sites carried out surveys 1-3 while survey 4 was conducted only in 3 sites. Surveys were usually performed during the peak malaria parasite transmission season, in one home visit, when medical history and malaria risk factors/prevention measures were collected, and a blood sample taken for rapid diagnostic test, microscopy, and haemoglobin measurement. PfPR was estimated by site and age category. RESULTS: Overall, 6401 (survey 1), 6411 (survey 2), 6400 (survey 3), and 2399 (survey 4) individuals were included in the analyses. In the 6 months-4 years age group, the lowest prevalence (assessed using microscopy) was observed in 2 Tanzanian centres (4.6% for Korogwe and 9.95% for Bagamoyo) and Lambaréné, Gabon (6.0%), while the highest PfPR was recorded for Nanoro, Burkina Faso (52.5%). PfPR significantly decreased over the 3 years in Agogo (Ghana), Kombewa (Kenya), Lilongwe (Malawi), and Bagamoyo (Tanzania), and a trend for increased PfPR was observed over the 4 surveys for Kintampo, Ghana. Over the 4 surveys, for all sites, PfPR was predominantly higher in the 5-19 years group than in the other age categories. Occurrence of fever and anaemia was associated with high P. falciparum parasitaemia. Univariate analyses showed a significant association of anti-malarial treatment in 4 surveys (odds ratios [ORs]: 0.52, 0.52, 0.68, 0.41) and bed net use in 2 surveys (ORs: 0.63, 0.68, 1.03, 1.78) with lower risk of malaria infection. CONCLUSION: Local PfPR differed substantially between sites and age groups. In children 6 months-4 years old, a significant decrease in prevalence over the 3 years was observed in 4 out of the 8 study sites. Trial registration Clinical Trials.gov identifier: NCT01190202:NCT. GSK Study ID numbers: 114001.

Trend of RTS,S vaccine uptake in the malaria vaccine implementing programme (MVIP) pilot regions, Ghana; 2019-2022.

Introduction: The uptake trend of a new vaccine is unpredictable and may reflect the quality of introduction process and community acceptance. The objective of this study was to conduct a trend analysis of RTS,S malaria vaccine uptake in the seven pilot regions of Ghana from 2019 to 2022. The findings are envisaged to strengthen malaria vaccine introductions in the future. Methods: A retrospective analysis was conducted on routine childhood immunisation data for 2019-2022. Coverages for the first (RTS,S1), second (RTS,S2), third (RTS,S3) and fourth (RTS,S4) doses of malaria vaccine; third dose of diphtheria, tetanus, pertussis-containing vaccine (DTP3/Penta3); first dose measles-rubella (MR1) and second dose measles-rubella (MR2) vaccines were calculated. Dropout rates and uptake gaps were estimated to assess variations in the uptake of consecutive RTS,S schedules; and the differences in the uptake of RTS,S and the comparator vaccines, respectively. Results: Nationally, the coverages of the first three doses of the RTS,S malaria vaccine rose sharply from 2019 (RTS,S1 = 54.9 %; RTS,S2 = 54.6 %; RTS,S3 = 38.6 %) through 2020 (RTS,S1 = 70.7 %; RTS,S2 = 67.4 %; RTS,S3 = 66.3 %) to peaks in 2021 (RTS,S1 = 76.0 %; RTS,S2 = 73.1 %; RTS,S3 = 74.2 %), and declined marginally in 2022 (RTS,S1 = 74.0 %; RTS,S2 = 69.9 %; RTS,S3 = 71.3 %). For the fourth dose, the low uptake in 2020 (7.5 %) was followed by a steep rise in 2021 (46.9 %) that continued, but at a reduced rate to 50.6% in 2022. The dropout rates and uptake gaps were initially high but declined consistently over the study period. Generally, the trends in vaccination coverages, and dropout rates and uptake gaps at the national level were reflected in the respective regions. Conclusion: The coverage of RTS,S malaria vaccine improved consistently over the study period despite the low uptake in the early phase of the pilot. While the decreasing dropout rates and uptake gaps may indicate improved community acceptance, strengthening immunisation service delivery is crucial in sustaining the observed trajectory.

Exploring Shigella vaccine priorities and preferences: Results from a mixed-methods study in low- and middle-income settings.

Background: Shigella is the leading bacterial cause of diarrheal mortality in children and can cause long-term effects on growth and development. No licensed Shigella vaccines currently exist but several promising candidates are in development and could be available in the next five years. Despite Shigella being a well-known public health target of the World Health Organization for decades, given current burden estimates and competing preventable disease priorities in low-income settings, whether the availability of an effective Shigella vaccine will lead to its prioritization and widespread introduction among countries at highest risk is unknown. Methods: We conducted a mixed-methods study of national stakeholders and healthcare providers in five countries in Asia and Africa and regional stakeholders in the Pan American Health Organization to identify preferences and priorities for forthcoming Shigella vaccines. Results: In our study of 89 individuals, diarrhea was the most frequently mentioned serious health concern for children under five years. Antimicrobial resistance (AMR) was more often considered very concerning than diarrhea or stunting. Shigella awareness was high but not considered a serious health concern by most stakeholders. Most participants were willing to consider adding a new vaccine to the routine immunization schedule but expressed reservations about a Shigella vaccine because of lower perceived burden relative to other preventable diseases and an already crowded schedule; interest was highest among national stakeholders in countries receiving more financial support for immunization. The priority of a Shigella vaccine rose when participants considered vaccine impacts on reducing stunting and AMR. Participants strongly preferred oral and combination vaccines compared to injectable and a single-antigen presentations, citing greater perceived community acceptability. Conclusions: This study provides a critical opportunity to hear directly from country and regional stakeholders about health priorities and preferences around new vaccines. These findings should inform ongoing Shigella vaccine development efforts and eventual vaccine introduction and implementation planning.

National stakeholder preferences for next-generation rotavirus vaccines: Results from a six-country study.

BACKGROUND: Currently available live, oral rotavirus vaccines (LORVs) have significantly reduced severe rotavirus hospitalizations and deaths worldwide. However, LORVs are not as effective in low- and middle-income countries (LMIC) where rotavirus disease burden is highest. Next-generation rotavirus vaccine (NGRV) candidates in development may have a greater public health impact where they are needed most. The feasibility and acceptability of possible new rotavirus vaccines were explored as part of a larger public health value proposition for injectable NGRVs in LMICs. OBJECTIVE: To assess national stakeholder preferences for currently available LORVs and hypothetical NGRVs and understand rationales and drivers for stated preferences. METHODS: Interviews were conducted with 71 national stakeholders who influence vaccine policy and national programming. Stakeholders from Ghana, Kenya, Malawi, Peru, Senegal, and Sri Lanka were interviewed using a mixed-method guide. Vaccine preferences were elicited on seven vaccine comparisons involving LORVs and hypothetical NGRVs based on information presented comparing the vaccines' attributes. Reasons for vaccine preference were elicited in open-ended questions, and the qualitative data were analyzed on key preference drivers. RESULTS: Nearly half of the national stakeholders interviewed preferred a highly effective standalone, injectable NGRV over current LORVs. When presented as having similar efficacy to the LORV, however, very few stakeholders preferred the injectable NGRV, even at substantially lower cost. Similarly, a highly effective standalone injectable NGRV was generally not favored over an equally effective oral NGRV following a neonatal-infant schedule, despite higher cost of the neonatal option. An NGRV-DTP-containing combination vaccine was strongly preferred over all other options, whether delivered alone with efficacy similar to current LORVs or co-administered alongside an LORV (LORV + NGRV-DTP) to increase efficacy. CONCLUSION: Results from these national stakeholder interviews provide valuable insights to inform ongoing and future NGRV research and development.

Healthcare provider perspectives on delivering next generation rotavirus vaccines in five low-to-middle-income countries.

BACKGROUND: Live oral rotavirus vaccines (LORVs) have significantly reduced rotavirus hospitalizations and deaths worldwide. However, LORVs are less effective in low- and middle-income countries (LMICs). Next-generation rotavirus vaccines (NGRVs) may be more effective but require administration by injection or a neonatal oral dose, adding operational complexity. Healthcare providers (HPs) were interviewed to assess rotavirus vaccine preferences and identify delivery issues as part of an NGRV value proposition. OBJECTIVE: Determine HP vaccine preferences about delivering LORVs compared to injectable (iNGRV) and neonatal oral (oNGRV) NGRVs. METHODS: 64 HPs from Ghana, Kenya, Malawi, Peru, and Senegal were interviewed following a mixed-method guide centered on three vaccine comparisons: LORV vs. iNGRV; LORV vs. oNGRV; oNGRV vs. iNGRV. HPs reviewed attributes for each vaccine in the comparisons, then indicated and explained their preference. Additional questions elicited views about co-administering iNGRV+LORV for greater public health impact, a possible iNGRV-DTP-containing combination vaccine, and delivering neonatal doses. RESULTS: Almost all HPs preferred oral vaccine options over iNGRV, with many emphasizing an aversion to additional injections. Despite this strong preference, HPs described challenges delivering oral doses. Preferences for LORV vs. oNGRV were split, marked by disparate views on rotavirus disease epidemiology and the safety, need, and feasibility of delivering neonatal vaccines. Although overwhelmingly enthusiastic about an iNGRV-DTP-containing combination option, several HPs had concerns. HP views were divided on the feasibility of co-administering iNGRV+LORV, citing challenges around logistics and caregiver sensitization. CONCLUSION: Our findings provide valuable insights on delivering NGRVs in routine immunization. Despite opposition to injectables, openness to co-administering LORV+iNGRV to improve efficacy suggests future HP support of iNGRV if adequately informed of its advantages. Rationales for LORV vs. oNGRV underscore needs for training on rotavirus epidemiology and stronger service integration. Expressed challenges delivering existing LORVs merit further examination and indicate need for improved delivery.