Journal Article > CommentaryAbstract
Int Health. 2014 May 6; Volume 6 (Issue 1); DOI:10.1093/inthealth/ihu005
Grais RF, Adamou HO
Int Health. 2014 May 6; Volume 6 (Issue 1); DOI:10.1093/inthealth/ihu005
Other > Journal Blog
Lancet Global Health. 2017 November 10
Fotheringham C
Lancet Global Health. 2017 November 10
Journal Article > CommentaryFull Text
PLOS Med. 2013 November 5; Volume 10 (Issue 11); DOI:10.1371/journal.pmed.1001544
Minetti A, Bopp C, Fermon F, Francois G, Grais RF, et al.
PLOS Med. 2013 November 5; Volume 10 (Issue 11); DOI:10.1371/journal.pmed.1001544
Andrea Minetti and colleagues compare measles outbreak responses from the Democratic Republic of the Congo and Malawi and argue that outbreak response strategies should be tailored to local measles epidemiology. Please see later in the article for the Editors' Summary.
Journal Article > ReviewAbstract
Pathog Glob Health. 2014 January 1; Volume 108 (Issue 1); DOI:10.1179/2047773214Y.0000000126
Ali A, Jafri RZ, Messonnier N, Tevi-Benissan C, Durrheim DN, et al.
Pathog Glob Health. 2014 January 1; Volume 108 (Issue 1); DOI:10.1179/2047773214Y.0000000126
A number of countries now include meningococcal vaccines in their routine immunization programs. This review focuses on different approaches to including meningococcal vaccines in country programs across the world and their effect on the burden of invasive meningococcal disease (IMD) as reflected by pre and post-vaccine incidence rates in the last 20 years. Mass campaigns using conjugated meningococcal vaccines have lead to control of serogroup C meningococcal disease in the UK, Canada, Australia, Spain, Belgium, Ireland, and Iceland. Serogroup B disease, predominant in New Zealand, has been dramatically decreased, partly due to the introduction of an outer membrane vesicle (OMV) vaccine. Polysaccharide vaccines were used in high risk people in Saudi Arabia and Syria and in routine immunization in China and Egypt. The highest incidence region of the meningitis belt initiated vaccination with the serogroup A conjugate vaccine in 2010 and catch-up vaccination is ongoing. Overall results of this vaccine introduction are encouraging especially in countries with a moderate to high level of endemic disease. Continued surveillance is required to monitor effectiveness in countries that recently implemented these programs.
Conference Material > Abstract
Meakin S
Epicentre Scientific Day 2024. 2024 May 23
BACKGROUND
The recombinant vesicular stomatitis virus–Zaire Ebola virus (rVSV-ZEBOV) vaccine is the only vaccine recommended for use to respond to Zaire ebolavirus outbreaks by SAGE. A single ring vaccination trial found the efficacy to be 100%; however, no estimates of real-world effectiveness have yet been published.
METHODS
We conducted a retrospective test-negative case-control analysis to estimate effectiveness of rVSV-ZEBOV vaccination against Ebola virus disease (EVD) during the 2018 - 2020 epidemic in the Democratic Republic of the Congo (DRC), using data on suspected cases collected at Ebola treatment centres. Missing data were imputed using multivariate imputation. Among those who reported contact with an Ebola case before symptom onset, each EVD-positive case was matched to one EVD-negative control by sex, age, health zone and month of symptom onset. Effectiveness was then estimated from the odds ratio of being vaccinated vs. unvaccinated among cases and controls, after adjusting for the matching factors.
RESULTS
The primary study population contained 309 cases and controls each, on average, of which between 11 and 23 cases (3.6– 7.4%) and between 48 and 80 controls (16 – 26%) were recorded as vaccinated at least ten days before symptom onset. We found rVSV-ZEBOV vaccination at least ten days before symptom onset was 84% effective against developing EVD (95% credible interval [70%, 92%]). There was no apparent difference in effectiveness by sex, age, or due to a change in vaccination protocol.
CONCLUSION
This study is the first to estimate real-world effectiveness of rVSV-ZEBOV vaccination EVD during the second largest EVD outbreak ever recorded. Our findings confirm that rVSV-ZEBOV vaccination is highly protective against developing EVD and support its reactive, targeted use in at-risk people during future outbreaks.
The recombinant vesicular stomatitis virus–Zaire Ebola virus (rVSV-ZEBOV) vaccine is the only vaccine recommended for use to respond to Zaire ebolavirus outbreaks by SAGE. A single ring vaccination trial found the efficacy to be 100%; however, no estimates of real-world effectiveness have yet been published.
METHODS
We conducted a retrospective test-negative case-control analysis to estimate effectiveness of rVSV-ZEBOV vaccination against Ebola virus disease (EVD) during the 2018 - 2020 epidemic in the Democratic Republic of the Congo (DRC), using data on suspected cases collected at Ebola treatment centres. Missing data were imputed using multivariate imputation. Among those who reported contact with an Ebola case before symptom onset, each EVD-positive case was matched to one EVD-negative control by sex, age, health zone and month of symptom onset. Effectiveness was then estimated from the odds ratio of being vaccinated vs. unvaccinated among cases and controls, after adjusting for the matching factors.
RESULTS
The primary study population contained 309 cases and controls each, on average, of which between 11 and 23 cases (3.6– 7.4%) and between 48 and 80 controls (16 – 26%) were recorded as vaccinated at least ten days before symptom onset. We found rVSV-ZEBOV vaccination at least ten days before symptom onset was 84% effective against developing EVD (95% credible interval [70%, 92%]). There was no apparent difference in effectiveness by sex, age, or due to a change in vaccination protocol.
CONCLUSION
This study is the first to estimate real-world effectiveness of rVSV-ZEBOV vaccination EVD during the second largest EVD outbreak ever recorded. Our findings confirm that rVSV-ZEBOV vaccination is highly protective against developing EVD and support its reactive, targeted use in at-risk people during future outbreaks.
Conference Material > Abstract
Nesbitt RC
Epicentre Scientific Day Paris 2023. 2023 June 8
BACKGROUND
Hepatitis E causes high mortality among pregnant women with case fatality risks of 10-25%, and adverse fetal outcomes. Hecolin® is a safe and efficacious vaccine against Hepatitis E, but there is an evidence gap on its safety in pregnant women. In 2015 the WHO recommended its use in response to outbreaks, including vaccinating pregnant women. The first mass reactive vaccination campaign against Hepatitis E was conducted in Bentiu including pregnant women and achieved high administrative vaccination coverage. We aimed to document pregnancy outcomes in a cohort of vaccinated and non-vaccinated pregnant women.
METHODS
An exhaustive pregnancy census was conducted after the second vaccination round from 16 May to 30 June 2022 to recruit women who were pregnant between 1 January 2022 and the interview date. Women were recontacted a minimum of 28 days after expected delivery to assess pregnancy outcome. Categorization of the cohort according to timing of potential vaccine exposure in pregnancy and regression models to evaluate the association between at least one dose in pregnancy and pregnancy outcomes is ongoing.
RESULTS
Of 20,674 women of childbearing age who consented for interview, 3,458 (16.7%) reported being pregnant since 1 January 2022. Women were a mean of 25.5 years old, had a median of 2 previous pregnancies (0-11), and 21 (0.6%) reported experiencing jaundice during their current pregnancy. Overall, 2723 (78.7%) women received at least one dose of Hecolin®. Access to delivery care was high, with 90% of women delivering in a health facility; 357 (10.3%) women reported a complication during delivery and 16 (0.5%) reported a caesarean section. According to interview, 3233 (93.5%) women had a livebirth, and 225 (6.9%) had a pregnancy loss, including 57 (1.6%) reported stillbirths, translating to a stillbirth rate of 17.6/1000 pregnancies, compared to the national estimate of 25.8/1000 pregnancies.
CONCLUSION
It was feasible to implement an observational study on the safety of vaccination in pregnancy alongside the first deployment of Hecolin® in a humanitarian emergency setting. Access to delivery care is reflected in the lower than national average rate of stillbirth in the camp. Results are expected to narrow the evidence gap on the safety of this vaccine in pregnancy.
KEY MESSAGE
A cohort study on the safety of vaccination in pregnancy was implemented alongside the first deployment of Hecolin® in a humanitarian emergency setting. Preliminary results show overall high coverage with at least one dose and access to delivery care among women in the cohort
This abstract is not to be quoted for publication.
Hepatitis E causes high mortality among pregnant women with case fatality risks of 10-25%, and adverse fetal outcomes. Hecolin® is a safe and efficacious vaccine against Hepatitis E, but there is an evidence gap on its safety in pregnant women. In 2015 the WHO recommended its use in response to outbreaks, including vaccinating pregnant women. The first mass reactive vaccination campaign against Hepatitis E was conducted in Bentiu including pregnant women and achieved high administrative vaccination coverage. We aimed to document pregnancy outcomes in a cohort of vaccinated and non-vaccinated pregnant women.
METHODS
An exhaustive pregnancy census was conducted after the second vaccination round from 16 May to 30 June 2022 to recruit women who were pregnant between 1 January 2022 and the interview date. Women were recontacted a minimum of 28 days after expected delivery to assess pregnancy outcome. Categorization of the cohort according to timing of potential vaccine exposure in pregnancy and regression models to evaluate the association between at least one dose in pregnancy and pregnancy outcomes is ongoing.
RESULTS
Of 20,674 women of childbearing age who consented for interview, 3,458 (16.7%) reported being pregnant since 1 January 2022. Women were a mean of 25.5 years old, had a median of 2 previous pregnancies (0-11), and 21 (0.6%) reported experiencing jaundice during their current pregnancy. Overall, 2723 (78.7%) women received at least one dose of Hecolin®. Access to delivery care was high, with 90% of women delivering in a health facility; 357 (10.3%) women reported a complication during delivery and 16 (0.5%) reported a caesarean section. According to interview, 3233 (93.5%) women had a livebirth, and 225 (6.9%) had a pregnancy loss, including 57 (1.6%) reported stillbirths, translating to a stillbirth rate of 17.6/1000 pregnancies, compared to the national estimate of 25.8/1000 pregnancies.
CONCLUSION
It was feasible to implement an observational study on the safety of vaccination in pregnancy alongside the first deployment of Hecolin® in a humanitarian emergency setting. Access to delivery care is reflected in the lower than national average rate of stillbirth in the camp. Results are expected to narrow the evidence gap on the safety of this vaccine in pregnancy.
KEY MESSAGE
A cohort study on the safety of vaccination in pregnancy was implemented alongside the first deployment of Hecolin® in a humanitarian emergency setting. Preliminary results show overall high coverage with at least one dose and access to delivery care among women in the cohort
This abstract is not to be quoted for publication.
Journal Article > ResearchFull Text
Sci Rep. 2016 October 24; Volume 6; 35742.; DOI:10.1038/srep35742
Iyer AS, Ryan ET, Martin S, Legros D, Lessler J, et al.
Sci Rep. 2016 October 24; Volume 6; 35742.; DOI:10.1038/srep35742
Despite recent large-scale cholera outbreaks, little is known about the immunogenicity of oral cholera vaccines (OCV) in African populations, particularly among those at highest cholera risk. During a 2015 preemptive OCV campaign among internally displaced persons in South Sudan, a year after a large cholera outbreak, we enrolled 37 young children (1-5 years old), 67 older children (6-17 years old) and 101 adults (≥18 years old), who received two doses of OCV (Shanchol) spaced approximately 3 weeks apart. Cholera-specific antibody responses were determined at days 0, 21 and 35 post-immunization. High baseline vibriocidal titers (>80) were observed in 21% of the participants, suggesting recent cholera exposure or vaccination. Among those with titers ≤80, 90% young children, 73% older children and 72% adults seroconverted (≥4 fold titer rise) after the 1(st) OCV dose; with no additional seroconversion after the 2(nd) dose. Post-vaccination immunological endpoints did not differ across age groups. Our results indicate Shanchol was immunogenic in this vulnerable population and that a single dose alone may be sufficient to achieve similar short-term immunological responses to the currently licensed two-dose regimen. While we found no evidence of differential response by age, further immunologic and epidemiologic studies are needed.
Journal Article > ResearchFull Text
PLoS Negl Trop Dis. 2015 December 29; Volume 9 (Issue 12); e0004274.; DOI:10.1371/journal.pntd.0004274
Grout L, Martinez-Pino I, Ciglenecki I, Keita S, Diallo AK, et al.
PLoS Negl Trop Dis. 2015 December 29; Volume 9 (Issue 12); e0004274.; DOI:10.1371/journal.pntd.0004274
INTRODUCTION
Since 2010, WHO has recommended oral cholera vaccines as an additional strategy for cholera control. During a cholera episode, pregnant women are at high risk of complications, and the risk of fetal death has been reported to be 2-36%. Due to a lack of safety data, pregnant women have been excluded from most cholera vaccination campaigns. In 2012, reactive campaigns using the bivalent killed whole-cell oral cholera vaccine (BivWC), included all people living in the targeted areas aged ≥ 1 year regardless of pregnancy status, were implemented in Guinea. We aimed to determine whether there was a difference in pregnancy outcomes between vaccinated and non-vaccinated pregnant women.
METHODS AND FINDINGS
From 11 November to 4 December 2013, we conducted a retrospective cohort study in Boffa prefecture among women who were pregnant in 2012 during or after the vaccination campaign. The primary outcome was pregnancy loss, as reported by the mother, and fetal malformations, after clinical examination. Primary exposure was the intake of the BivWC vaccine (Shanchol) during pregnancy, as determined by a vaccination card or oral history. We compared the risk of pregnancy loss between vaccinated and non-vaccinated women through binomial regression analysis. A total of 2,494 pregnancies were included in the analysis. The crude incidence of pregnancy loss was 3.7% (95%CI 2.7-4.8) for fetuses exposed to BivWC vaccine and 2.6% (0.7-4.5) for non-exposed fetuses. The incidence of malformation was 0.6% (0.1-1.0) and 1.2% (0.0-2.5) in BivWC-exposed and non-exposed fetuses, respectively. In both crude and adjusted analyses, fetal exposure to BivWC was not significantly associated with pregnancy loss (adjusted risk ratio (aRR = 1.09 [95%CI: 0.5-2.25], p = 0.818) or malformations (aRR = 0.50 [95%CI: 0.13-1.91], p = 0.314).
CONCLUSIONS
In this large retrospective cohort study, we found no association between fetal exposure to BivWC and risk of pregnancy loss or malformation. Despite the weaknesses of a retrospective design, we can conclude that if a risk exists, it is very low. Additional prospective studies are warranted to add to the evidence base on OCV use during pregnancy. Pregnant women are particularly vulnerable during cholera episodes and should be included in vaccination campaigns when the risk of cholera is high, such as during outbreaks.
Since 2010, WHO has recommended oral cholera vaccines as an additional strategy for cholera control. During a cholera episode, pregnant women are at high risk of complications, and the risk of fetal death has been reported to be 2-36%. Due to a lack of safety data, pregnant women have been excluded from most cholera vaccination campaigns. In 2012, reactive campaigns using the bivalent killed whole-cell oral cholera vaccine (BivWC), included all people living in the targeted areas aged ≥ 1 year regardless of pregnancy status, were implemented in Guinea. We aimed to determine whether there was a difference in pregnancy outcomes between vaccinated and non-vaccinated pregnant women.
METHODS AND FINDINGS
From 11 November to 4 December 2013, we conducted a retrospective cohort study in Boffa prefecture among women who were pregnant in 2012 during or after the vaccination campaign. The primary outcome was pregnancy loss, as reported by the mother, and fetal malformations, after clinical examination. Primary exposure was the intake of the BivWC vaccine (Shanchol) during pregnancy, as determined by a vaccination card or oral history. We compared the risk of pregnancy loss between vaccinated and non-vaccinated women through binomial regression analysis. A total of 2,494 pregnancies were included in the analysis. The crude incidence of pregnancy loss was 3.7% (95%CI 2.7-4.8) for fetuses exposed to BivWC vaccine and 2.6% (0.7-4.5) for non-exposed fetuses. The incidence of malformation was 0.6% (0.1-1.0) and 1.2% (0.0-2.5) in BivWC-exposed and non-exposed fetuses, respectively. In both crude and adjusted analyses, fetal exposure to BivWC was not significantly associated with pregnancy loss (adjusted risk ratio (aRR = 1.09 [95%CI: 0.5-2.25], p = 0.818) or malformations (aRR = 0.50 [95%CI: 0.13-1.91], p = 0.314).
CONCLUSIONS
In this large retrospective cohort study, we found no association between fetal exposure to BivWC and risk of pregnancy loss or malformation. Despite the weaknesses of a retrospective design, we can conclude that if a risk exists, it is very low. Additional prospective studies are warranted to add to the evidence base on OCV use during pregnancy. Pregnant women are particularly vulnerable during cholera episodes and should be included in vaccination campaigns when the risk of cholera is high, such as during outbreaks.
Journal Article > ResearchFull Text
Vaccine. 2021 November 9; Volume 9 (Issue 11); 1303.; DOI:10.3390/vaccines9111303
Urrunaga-Pastor D, Herrera-Anazco P, Uyen-Cateriano A, Toro-Huamanchumo CJ, Rodriguez-Morales AJ, et al.
Vaccine. 2021 November 9; Volume 9 (Issue 11); 1303.; DOI:10.3390/vaccines9111303
We aimed to estimate the prevalence and factors associated with parents' non-intention to vaccinate their children and adolescents against COVID-19 in Latin America and the Caribbean (LAC). We performed a secondary analysis using a database generated by the University of Maryland and Facebook (Facebook, Inc., Menlo Park, CA, USA). We included adult (18 and over) Facebook users residing in LAC who responded to the survey between 20 May 2021 and 14 July 2021. We included sociodemographic characteristics, comorbidities, mental health, economic and food insecurity, compliance with mitigation strategies against COVID-19, and practices related to vaccination against this disease. We estimated the crude (cPR) and adjusted (aPR) prevalence ratios with their respective 95%CI. We analyzed a sample of 227,740 adults from 20 LAC countries. The prevalence of parents' non-intention to vaccinate their children and adolescents against COVID-19 was 7.8% (n = 15,196). An age above 35 years old, educational level above college, compliance with physical distancing, use of masks, having economic insecurity, having had COVID-19, anxiety symptoms, depressive symptoms, having a chronic condition or two or more comorbidities, and being vaccinated were associated with a lower prevalence of non-intention to vaccinate children and adolescents against COVID-19. Living in a town, a village, or a rural area was associated with a higher prevalence of non-intention to vaccinate children and adolescents against COVID-19. Approximately nine out of ten parents in LAC intended to vaccinate their children and adolescents against COVID-19. Our results allow for understanding parents' intentions to vaccinate children and adolescents and help promote and develop education strategies for national vaccination plans against COVID-19.
Journal Article > ResearchFull Text
Vaccine. 2006 May 29; Volume 24 (Issue 22); 4890-4895.; DOI:10.1016/j.vaccine.2005.10.006
Cavailler P, Perroud V, Mcchesney M, Ampuero S, Guerin PJ, et al.
Vaccine. 2006 May 29; Volume 24 (Issue 22); 4890-4895.; DOI:10.1016/j.vaccine.2005.10.006
We conducted a study to assess the feasibility and the potential vaccine coverage of a mass vaccination campaign using a two-dose oral cholera vaccine in an urban endemic neighbourhood of Beira, Mozambique. The campaign was conducted from December 2003 to January 2004. Overall 98,152 doses were administered, and vaccine coverage of the target population was 58.6% and 53.6% for the first and second rounds, respectively. The direct cost of the campaign, which excludes the price of the vaccine, amounted to slightly over 90,000 dollars, resulting in the cost per fully vaccinated person of 2.09 dollars, which is relatively high. However, in endemic settings where outbreaks are likely to occur, integrating cholera vaccination into the routine activities of the public health system could reduce such costs.