Vaccination coverage and adverse events following a reactive vaccination campaign against hepatitis E in Bentiu displaced persons camp, South Sudan.

INTRODUCTION: Hepatitis E (HEV) genotypes 1 and 2 are the common cause of jaundice and acute viral hepatitis that can cause large-scale outbreaks. HEV infection is associated with adverse fetal outcomes and case fatality risks up to 31% among pregnant women. An efficacious three-dose recombinant vaccine (Hecolin) has been licensed in China since 2011 but until 2022, had not been used for outbreak response despite a 2015 WHO recommendation. The first ever mass vaccination campaign against hepatitis E in response to an outbreak was implemented in 2022 in Bentiu internally displaced persons camp in South Sudan targeting 27,000 residents 16-40 years old, including pregnant women. METHODS: We conducted a vaccination coverage survey using simple random sampling from a sampling frame of all camp shelters following the third round of vaccination. For survey participants vaccinated in the third round in October, we asked about the onset of symptoms experienced within 72 hours of vaccination. During each of the three vaccination rounds, passive surveillance of adverse events following immunisation (AEFI) was put in place at vaccination sites and health facilities in Bentiu IDP camp. RESULTS: We surveyed 1,599 individuals and found that self-reported coverage with one or more dose was 86% (95% CI 84-88%), 73% (95% CI 70-75%) with two or more doses and 58% (95% CI 55-61%) with three doses. Vaccination coverage did not differ significantly by sex or age group. We found no significant difference in coverage of at least one dose between pregnant and non-pregnant women, although coverage of at least two and three doses was 8 and 14 percentage points lower in pregnant women. The most common reasons for non-vaccination were temporary absence or unavailability, reported by 60% of unvaccinated people. Passive AEFI surveillance captured few mild AEFI, and through the survey we found that 91 (7.6%) of the 1,195 individuals reporting to have been vaccinated in October 2022 reported new symptoms starting within 72 hours after vaccination, most commonly fever, headache or fatigue. CONCLUSIONS: We found a high coverage of at least one dose of the Hecolin vaccine following three rounds of vaccination, and no severe AEFI. The vaccine was well accepted and well tolerated in the Bentiu IDP camp community and should be considered for use in future outbreak response.

A post-conflict vaccination campaign, Central African Republic.

OBJECTIVE: To rapidly increase childhood immunization through a preventive, multi-antigen, vaccination campaign in Mambéré-Kadéï prefecture, Central African Republic, where a conflict from 2012 to 2015 reduced vaccination coverage. METHODS: The three-round campaign took place between December 2015 and June 2016 using: (i) oral poliomyelitis vaccine (OPV); (ii) combined diphtheria, tetanus and pertussis (DTP) vaccine, Haemophilus influenza type B (Hib) and hepatitis B (DTP-Hib-hepatitis B) vaccine; (iii) pneumococcal conjugate vaccine (PCV); (iv) measles vaccine; and (v) yellow fever vaccine. Administrative data were collected on vaccines administered by age group and vaccination coverage surveys were carried out before and after the campaign. FINDINGS: Overall, 294 054 vaccine doses were administered. Vaccination coverage for children aged 6 weeks to 59 months increased to over 85% for the first doses of OPV, DTP-Hib-hepatitis B vaccine and PCV and, in children aged 9 weeks to 59 months, to over 70% for the first measles vaccine dose. In children aged 6 weeks to 23 months, coverage of the second doses of OPV, DTP-Hib-hepatitis B vaccine and PCV was over 58% and coverage of the third doses of OPV and DTP-Hib-hepatitis B vaccine was over 20%. Moreover, 61% (5804/9589) of children aged 12 to 23 months had received two PCV doses and 90% (25933/28764) aged 24 to 59 months had received one dose. CONCLUSION: A preventive, multi-antigen, vaccination campaign was effective in rapidly increasing immunization coverage in a post-conflict setting. To sustain high coverage, routine immunization must be reinforced.

The new WHO decision-making framework on vaccine use in acute humanitarian emergencies: MSF experience in Minkaman, South Sudan.

INTRODUCTION: The main causes of death during population movements can be prevented by addressing the population's basic needs. In 2013, the World Health Organization (WHO) issued a framework for decision making to help prioritize vaccinations in acute humanitarian emergencies. This article describes MSF's experience of applying this framework in addition to addressing key population needs in a displacement setting in Minkaman, South Sudan. CASE DESCRIPTION: Military clashes broke out in South Sudan in December 2013. By May 2014, Minkaman, a village in the Lakes State, hosted some 85,000 displaced people. MSF arrived in Minkaman on 28 December 2013 and immediately provided interventions to address the key humanitarian needs (health care, access to drinking water, measles vaccination). The WHO framework was used to identify priority vaccines: those preventing outbreaks (measles, polio, oral cholera vaccine, and vaccine against meningococcal meningitis A (MenAfrivac®)) and those reducing childhood morbidity and mortality (pentavalent vaccine that combines diphtheria, tetanus, whooping cough, hepatitis B, and Haemophilus influenzae type B; pneumococcal vaccine; and rotavirus vaccine). By mid-March, access to primary and secondary health care was ensured, including community health activities and the provision of safe water. Mass vaccination campaigns against measles, polio, cholera, and meningitis had been organized. Vaccination campaigns against the main deadly childhood diseases, however, were not in place owing to lack of authorization by the Ministry of Health (MoH). CONCLUSIONS: The first field use of the new WHO framework for prioritizing vaccines in acute emergencies is described. Although MSF was unable to implement the full package of priority vaccines because authorization could not be obtained from the MoH, a series of mass vaccination campaigns against key epidemic-prone diseases was successfully implemented within a complex emergency context. Together with covering the population's basic needs, this might have contributed to reducing mortality levels below the emergency threshold and to the absence of epidemics. For the WHO framework to be used to its full potential it must not only be adapted for field use but, most importantly, national decision makers should be briefed on the framework and its practical implementation.

A post-conflict vaccination campaign, Central African Republic

Objective : To rapidly increase childhood immunization through a preventive, multi-antigen, vaccination campaign in Mambéré-Kadéï prefecture, Central African Republic, where a conflict from 2012 to 2015 reduced vaccination coverage. Methods:The three-round campaign took place between December 2015 and June 2016 using: (i) oral poliomyelitis vaccine (OPV); (ii) combined diphtheria, tetanus and pertussis (DTP) vaccine, Haemophilus influenza type B (Hib) and hepatitis B (DTP­Hib­hepatitis B) vaccine; (iii) pneumococcal conjugate vaccine (PCV); (iv) measles vaccine; and (v) yellow fever vaccine. Administrative data were collected on vaccines administered by age group and vaccination coverage surveys were carried out before and after the campaign.Findings:Overall, 294 054 vaccine doses were administered. Vaccination coverage for children aged 6 weeks to 59 months increased to over 85% for the first doses of OPV, DTP­Hib­hepatitis B vaccine and PCV and, in children aged 9 weeks to 59 months, to over 70% for the first measles vaccine dose. In children aged 6 weeks to 23 months, coverage of the second doses of OPV, DTP­Hib­hepatitis B vaccine and PCV was over 58% and coverage of the third doses of OPV and DTP­Hib­hepatitis B vaccine was over 20%. Moreover, 61% (5804/9589) of children aged 12 to 23 months had received two PCV doses and 90% (25933/28764) aged 24 to 59 months had received one dose.Conclusion:A preventive, multi-antigen, vaccination campaign was effective in rapidly increasing immunization coverage in a post-conflict setting. To sustain high coverage, routine immunization must be reinforced

Changes in Health-Seeking Behavior Did Not Result in Increased All-Cause Mortality During the Ebola Outbreak in Western Area, Sierra Leone.

Little is known about the residual effects of the west African Ebola virus disease (Ebola) epidemic on non-Ebola mortality and health-seeking behavior in Sierra Leone. We conducted a retrospective household survey to estimate mortality and describe health-seeking behavior in Western Area, Sierra Leone, between May 25, 2014, and February 16, 2015. We used two-stage cluster sampling, selected 30 geographical sectors with probability proportional to population size, and sampled 30 households per sector. Survey teams conducted face-to-face interviews and collected information on mortality and health-seeking behavior. We calculated all-cause and Ebola-specific mortality rates and compared health-seeking behavior before and during the Ebola epidemic using χ2 and Fisher's exact tests. Ninety-six deaths, 39 due to Ebola, were reported in 898 households. All-cause and Ebola-specific mortality rates were 0.52 (95% confidence interval [CI] = 0.29-0.76) and 0.19 (95% CI = 0.01-0.38) per 10,000 inhabitants per day, respectively. Of those households that reported a sick family member during the month before the survey, 86% (73/85) sought care at a health facility before the epidemic, compared with 58% (50/86) in February 2015 (P = 0.013). Reported self-medication increased from 4% (3/85) before the epidemic to 23% (20/86) during the epidemic (P = 0.013). Underutilization of health services and increased self-medication did not show a demonstrable effect on non-Ebola-related mortality. Nevertheless, the residual effects of outbreaks need to be taken into account for the future. Recovery efforts should focus on rebuilding both the formalized health system and the population's trust in it.

High levels of mortality, malnutrition, and measles, among recently-displaced Somali refugees in Dagahaley camp, Dadaab refugee camp complex, Kenya, 2011.

BACKGROUND: Following a rapid influx of over 200,000 displaced Somalis into the Dadaab refugee camp complex in Kenya, Médecins Sans Frontières conducted a mortality and nutrition survey of the population living in Bulo Bacte, a self-settled area surrounding Dagahaley camp (part of this complex). METHODS: The survey was conducted between 31st July and 10th August 2011. We exhaustively interviewed representatives from all households in Bulo Bacte, collecting information on deaths, births, and population movements during the recall period (15th February 2011 to survey date), in order to provide estimates of retrospective death rates. We recorded the mid-upper arm circumference and presence or absence of bipedal oedema of all children of height 67-<110 cm to provide estimates of global and severe acute malnutrition. RESULTS: The surveyed population included 26,583 individuals, of whom 6,488 (24.4%) were children aged under 5 years. There were 360 deaths reported during the 177 days of the recall period, of which 186 (52%) were among children aged under 5 years. The crude death rate for the entire recall period was 0.8 per 10,000 person-days. The under-5 death rate was 1.8 per 10,000 person-days. More than two-thirds of all deaths were reported to have been associated with diarrhoea (25%), cough or other breathing difficulties (24%), or with fever (19%). Measles accounted for a reported 17% of all deaths; this was due to a measles outbreak that occurred between June and October 2011.Global acute malnutrition was observed in 13.4%, and severe acute malnutrition in 3.0%, of children measuring 67-<110 cm. Among children measuring 110-< 140 cm, 9.8% met the admission criteria for entry into the nutritional programme. Trends of decreasing death rates and malnutrition prevalence with length of stay in Bulo Bacte were observed. CONCLUSIONS: We report high death rates and prevalence of malnutrition among this population, reflecting at least a partial failure of the various humanitarian and governmental actors to adequately safeguard the welfare of this population. An outbreak of measles and long delays before registration should not have occurred. The recommendations for measles vaccination among crisis-affected populations should be revised to take into account the epidemiologic context. Organisations must be sensitive and reactive to changes in the health status of the populations they assist.