Safety, reactogenicity, and immunogenicity of a 2-dose Ebola vaccine regimen of Ad26.ZEBOV followed by MVA-BN-Filo in healthy adult pregnant women: study protocol for a phase 3 open-label randomized controlled trial

Immunogenicity and safety of ebolavirus vaccines in healthy adults: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

This review aimed to systematically evaluate the immunogenicity and safety of the candidate Ebola virus vaccine (EVV).

METHODS

We searched five databases for randomized controlled trials (RCTs) evaluating the effects of EVV on healthy adults. The primary outcomes were relative risk (RR) of sero-conversion or sero-response of EVV in healthy adults between the groups that received EVV and the controls.

RESULTS

Twenty-nine RCTs (n = 23573) were included. There was a significant difference in RR of sero-conversion of EVV (RR 13.18; 95% CI 11.28-15.41; I2 = 33%; P < 0.01) between the two groups. There was a significant difference in RR of adverse events (AEs) of EVV (RR 1.49; 95% CI 1.27-1.74; I2 = 88%; P < 0.01), although no difference in RR of serious AE (SAE) between the two groups. Subgroup analysis showed that there was no significant difference in RR of AEs for DNAEBO, EBOV-GP, MVA, and rVSVN4CT1 vaccines, compared with controls.

CONCLUSIONS

The DNAEBO, EBOV-GP, MVA, and rVSVN4CT1 vaccines are likely to be safe and immunogenic, tending to support the vaccination against Ebola disease. These findings should provide much-needed evidence for public health policy makers to develop preventive measures based on disease prevalence features and socio-economic conditions.

Best practices and lessons learned from implementing a massive Ebola vaccination program: Summarizing UMURINZI team experience

Background and Aims

The unified Rwandan initiative for national ZEBOVAC immunization (UMURINZI) program's community engagement component was enacted to mobilize and vaccinate high-risk community members. This article describes best practices and lessons learned from the implementation of UMURINZI, a large-scale Ebola vaccination program.

Methods

The population deemed to be at risk for EVD consisted of people who frequently cross Rwanda and the Democratic Republic of Congo (DRC) borders including those coming from Kigali City, potential first responders who have not previously been vaccinated against EVD, as well as people who reside in high-risk border-proximate areas of the Rubavu and Rusizi districts in the Western Province of Rwanda. These districts were selected because of their proximity to high-traffic borders linking Rwanda to DRC's cities near an active Ebola outbreak. Volunteers of this program were adults, adolescents, and children aged 2 years or above who resided in the selected communities. Recruitment at the sites was conducted in close collaboration with each health area's Community Health Workers (CHWs). Volunteers were informed that the program involved being fully vaccinated (two doses of Ebola vaccines) within 2 months apart in the allocated vaccination sites.

Results

Lessons learned were categorized into four pillars: infrastructure, leadership, myths, and partnership with respect. The best practices that were used during the implementation of the UMURINZI program were the results of a collaboration among CHWs, the involvement of national and local leaders, the use of a comprehensive engagement plan, and training. The study also had limitations.

Conclusion

We described best practices and lessons learned during the implementation of the UMURINZI program in Rwanda. These practices and lessons learned represent promising options that could contribute to better community members' participation in mass vaccination programs. Hence, we demonstrated that rigorously designed community awareness and sensitization programs are effective for the implementation of similar programs in resource-limited settings.

Monitoring of Adverse Events in Recipients of the 2-Dose Ebola Vaccine Regimen of Ad26.ZEBOV Followed by MVA-BN-Filo in the UMURINZI Ebola Vaccination Campaign

BACKGROUND

From 2019 to 2021, Rwandan residents of the border with the Democratic Republic of the Congo were offered the Ad26.ZEBOV (adenovirus type 26 vector vaccine encoding Ebola virus glycoprotein) and MVA-BN-Filo (modified vaccinia virus Ankara vector vaccine, encoding glycoproteins from Ebola, Sudan, Marburg, and nucleoprotein from Tai Forest viruses) Ebola vaccine regimen.

METHODS

Nonpregnant persons aged ≥2 years were eligible. Unsolicited adverse events (UAEs) were reported through phone calls or visits, and serious adverse events (SAEs) were recorded per International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use guidelines.

RESULTS

Following Ad26.ZEBOV, UAEs were reported by 0.68% of 216 113 vaccinees and were more common in younger children (aged 2-8 years, 1.2%) compared with older children (aged 9-17 years, 0.4%) and adults (aged ≥18 years, 0.7%). Fever and headache were the most reported symptoms. All 17 SAEs related to vaccine were in children aged 2-8 years (10 postvaccination febrile convulsions ± gastroenteritis and 7 fever and/or gastroenteritis). The incidence of febrile seizures was 8 of 26 062 (0.031%) prior to initiation of routine acetaminophen in December 2020 and 2 of 15 897 (0.013%) thereafter. Nonobstetric SAEs were similar in males and females. All 20 deaths were unrelated to vaccination. Young girls and adult women with UAEs were less likely to receive the second dose than those without UAEs. Seven unrelated SAEs occurred in 203 267 MVA-BN-Filo recipients.

CONCLUSIONS

Postvaccination febrile convulsions in young children were rare but not previously described after Ad26.ZEBOV and were reduced with routine acetaminophen. The regimen was otherwise safe and well-tolerated.