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"Clemens, Ralf"
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Impact of the COVID-19 pandemic on the routine immunization system in Bangladesh
by
Costa Clemens, Sue Ann
,
Islam, Md Foyjul
,
Hossen, Md. Tanvir
in
Bangladesh - epidemiology
,
BCG vaccines
,
Business metrics
2025
The COVID-19 pandemic has put immense pressure on countries’ health structures to maintain routine immunization and VPD surveillance programs, especially in LMICs such as Bangladesh. Understanding the effects of COVID-19 will allow countries like Bangladesh to become better prepared for future health emergencies, so this study explored the effects of COVID-19 on routine immunization and VPD surveillance programs in Bangladesh. With a sequential mixed-method approach, the quantitative data was collected from the DHIS2 for January 2019-December 2021. The qualitative data was collected from ten KIIs, which was conducted with the key stakeholders of EPI and VPD surveillance in Bangladesh. Findings suggest that there had been three drop-rebound periods in the routine immunization program in Bangladesh. The study identified that Bangladesh was able to catch up with the pre-pandemic level immunization within four to six months from the first drop, and the immunization drops became less severe with the progression of time. COVID-19-related movement restrictions, lack of workforce, fear and concern regarding COVID-19, prioritizing COVID-19 vaccination, lack of a comprehensive EPI structure in urban compared to rural areas, and lack of knowledge to conduct EPI and VPD activities amidst the pandemic situation were identified as the main reasons for these drops.
Journal Article
Oil-in-Water Emulsion Adjuvant with Influenza Vaccine in Young Children
by
Wutzler, Peter
,
Kieninger-Baum, Dorothee
,
Knuf, Markus
in
Adjuvants
,
Adjuvants, Immunologic - adverse effects
,
Biological and medical sciences
2011
Over two influenza seasons, 4707 children were randomly assigned to either control (noninfluenza) vaccines or trivalent influenza vaccines with or without adjuvant MF59. The vaccine with MF59 proved efficacious in this vulnerable population.
Children have the highest rates of seasonal influenza infection and illness, with amplification of community viral transmission. Thus, numerous countries recommend routine seasonal vaccination to protect children directly and the entire population indirectly.
1
–
9
Parenteral trivalent inactivated influenza vaccine (TIV) is poorly immunogenic in young children, with an efficacy of only 59.0% in children older than 2 years of age.
10
–
12
Although intranasal live attenuated influenza vaccine has an efficacy of 69.2 to 95.6% in children 2 to 7 years of age, it cannot be used in children under 2 years of age because of the increased risk of hospitalization . . .
Journal Article
Safety and Immunogenicity of Different Formulations of Norovirus Vaccine Candidate in Healthy Adults: A Randomized, Controlled, Double-Blind Clinical Trial
2018
Bivalent (GI.1 and GII.4) virus-like particle norovirus candidate vaccine formulations were well tolerated and immunogenic, 1 dose inducing immune responses that persisted up to 1 year, which were not increased by inclusion of monophosphoryl lipid A or administration of a second dose.
Abstract
Background
We investigated safety and immunogenicity of 1–2 doses of different bivalent virus-like particle (VLP) norovirus vaccine candidate (NoV) formulations in healthy 18- to 64-year-olds.
Methods
On days 1 and 28, participants (n = 420) randomized to 14 equal groups received intramuscular control vaccine (hepatitis A) or 1 of 11 NoV formulations containing varying dosages of GI.1 and GII.4c genotype VLP antigens with aluminum hydroxide [Al(OH)3], and 0 μg, 15 μg, or 50 μg monophosphoryl lipid A (MPL). Immunogenicity was assessed on days 1, 28, 56, 208 and 393. Solicited local and systemic reactions were recorded for 7 days, unsolicited adverse events (AEs) until day 56, and serious AEs throughout the trial.
Results
All NoV formulations induced similar increases in pan-immunoglobulin, immunoglobulin A, and histo-blood group binding antigen-blocking antibodies by day 56, mostly after 1 dose, that persisted above baseline to day 393. Higher GI.1 content interfered with GII.4c responses, and responses did not benefit from MPL. Overall reactogenicity consisted of mainly mild injection site pain, headache, and fatigue. No vaccine-related serious AEs were reported.
Conclusions
All candidate NoV formulations were well tolerated. Overall, 15 μg GI.1/50 μg GII.4c elicited the best balance of immunogenicity with no clear benefit of MPL, and is the candidate formulation being taken forward in clinical development.
Clinical Trials Registration
NCT02038907.
Journal Article
Immunogenicity and tolerability of a multicomponent meningococcal serogroup B (4CMenB) vaccine in healthy adolescents in Chile: a phase 2b/3 randomised, observer-blind, placebo-controlled study
by
Valenzuela, María Teresa
,
Wang, Huajun
,
Prado, Valeria
in
Adolescent
,
Adolescents
,
Analysis of Variance
2012
Effective glycoconjugate vaccines against Neisseria meningitidis serogroups A, C, W-135, and Y have been developed, but serogroup B remains a major cause of severe invasive disease in infants and adolescents worldwide. We assessed immunogenicity and tolerability of a four-component vaccine (4CMenB) in adolescents.
We did a randomised, observer-blind, placebo-controlled, study at 12 sites in Santiago and Valparaíso, Chile. Adolescents aged 11–17 years received one, two, or three doses of 4CMenB at 1 month, 2 month, or 6 month intervals. Immunogenicity was assessed as serum bactericidal activity using human complement (hSBA) against three reference strains for individual vaccine antigens, and assessed by ELISA against the fourth strain. Local and systemic reactions were recorded 7 days after each vaccination, and adverse events were monitored throughout the study. Participants were initially randomised to five groups (3:3:3:3:1) during the primary phase to receive either one dose, two doses 1 or 2 months apart, or three doses of 4CMenB, or three doses of placebo, with an additional three groups generated for the booster phase. All subjects received at least one dose of 4CMenB. Geometric mean titres, proportions of participants with serum bactericidal antibody titres of 4 or more, and Clopper-Pearson 95% CIs were calculated. The study is registered with ClinicalTrials.gov, number NCT00661713.
Overall, 1631 adolescents (mean age 13·8 [SD 1·9] years) received at least one dose of 4CMenB. After two or three doses, 99–100% of recipients had hSBA titres of 4 or more against test strains, compared with 92–97% after one dose (p<0·0145) and 29–50% after placebo. At 6 months 91–100% of participants still had titres of 4 or more for each strain after two or three doses, but only 73–76% after one dose; seroresponse rates reached 99–100% for each strain after second or third doses at 6 months. Local and systemic reaction rates were similar after each 4CMenB injection and did not increase with subsequent doses, but remained higher than placebo. No vaccine-related serious adverse events were reported and no significant safety signals were identified.
On the basis of immunogenicity responses this study provides evidence for an adolescent 4CMenB vaccine schedule of two doses, 1–6 months apart, to provide protection against meningococcal B infection. The extent of this protection against meningococcus B variants circulating worldwide will be determined by national surveys.
Novartis Vaccines and Diagnostics.
Journal Article
Immunogenicity and safety of a novel monovalent high-dose inactivated poliovirus type 2 vaccine in infants: a comparative, observer-blind, randomised, controlled trial
by
Molina, Natanael
,
Sáez-Llorens, Xavier
,
Weldon, William C
in
Antibodies, Viral - blood
,
Enterovirus
,
Feces - virology
2016
Following the proposed worldwide switch from trivalent oral poliovirus vaccine (tOPV) to bivalent types 1 and 3 OPV (bOPV) in 2016, inactivated poliovirus vaccine (IPV) will be the only source of protection against poliovirus type 2. With most countries opting for one dose of IPV in routine immunisation schedules during this transition because of cost and manufacturing constraints, optimisation of protection against all poliovirus types will be a priority of the global eradication programme. We assessed the immunogenicity and safety of a novel monovalent high-dose inactivated poliovirus type 2 vaccine (mIPV2HD) in infants.
This observer-blind, comparative, randomised controlled trial was done in a single centre in Panama. We enrolled healthy infants who had not received any previous vaccination against poliovirus. Infants were randomly assigned (1:1) by computer-generated randomisation sequence to receive a single dose of either mIPV2HD or standard trivalent IPV given concurrently with a third dose of bOPV at 14 weeks of age. At 18 weeks, all infants were challenged with one dose of monovalent type 2 OPV (mOPV2). Primary endpoints were seroconversion and median antibody titres to type 2 poliovirus 4 weeks after vaccination with mIPV2HD or IPV; and safety (as determined by the proportion and nature of serious adverse events and important medical events for 8 weeks after vaccination). The primary immunogenicity analyses included all participants for whom a post-vaccination blood sample was available. All randomised participants were included in the safety analyses. This trial is registered with ClinicalTrials.gov, number NCT02111135.
Between April 14 and May 9, 2014, 233 children were enrolled and randomly assigned to receive mIPV2HD (117 infants) or IPV (116 infants). 4 weeks after vaccination with mIPV2HD or IPV, seroconversion to poliovirus type 2 was recorded in 107 (93·0%, 95% CI 86·8–96·9) of 115 infants in the mIPV2HD group compared with 86 (74·8%, 65·8–82·4) of 115 infants in the IPV group (difference between groups 18·3%, 95% CI 5·0–31·1; p<0·0001), and median antibody titres against poliovirus type 2 were 181 (95% CI 72·0–362·0) in the mIPV2HD group and 36 (18·0–113·8) in the IPV group (difference between groups 98·8, 95% CI 60·7–136·9; p<0·0001). Serious adverse events were reported for six (5%) of 117 infants in the mIPV2HD group and seven (6%) of 116 infants in the IPV group during the 8-week period after vaccination; none were related to vaccination. No important medical events were reported.
Our findings lend support to the use of mIPV2HD as an option for stockpiling for outbreak response or primary protection in selected areas at risk for emergence of poliovirus type 2 during the next phase of the polio eradication plan.
Bill & Melinda Gates Foundation.
Journal Article
Seroepidemiology of respiratory syncytial virus infection in rural and semi-rural areas of the Littoral region of Cameroon
by
Mandi, Henshaw
,
Eyoh, Agnes
,
Yimer, Solomon
in
Cameroon
,
Cameroon - epidemiology
,
Care and treatment
2021
Background
The respiratory syncytial virus (RSV) has been established as a leading cause of acute lower respiratory illness (ALRI) in infants and children. In 2015, the global disease burden (GBD) study estimated that the overall RSV-ALRI mortality could be as high as 118,200, with most death occurring in low- and middle-incomes countries (LMIC). This study aimed to assess the burden of RSV infection among children less than 2 years with acute respiratory infections (ARI) in the Littoral region of Cameroon.
Methods
We carried out a cross-sectional study in seven health centres in the Littoral region of Cameroon
.
Venous blood was collected using serum separation tubes from eligible children who visited these health centres with acute respiratory infections. ELISA (Enzyme-linked immunosorbent assay) testing was used to assess the seroprevalence of anti-IgM RSV for the total population and by selected demographic and health parameters and potential risk factors.
Results
The overall RSV-associated ARI seroprevalence was 33% (95%CI:23.6–42.3; 33/100 children). The only demographic factor significantly associated with RSV acquisition was age of 6 months and below (odds ratio: 7.54 (2.62, 23.36);
p
= 0.000). Children who were clinically diagnosed to be concomitantly infected with malaria had a lower risk of RSV infection (odds ratio: 0.38 (0.14, 0.95;
P
= 0.03).
Conclusions
The RSV burden is high among children less than 2 years with ARI in the Littoral region of Cameroon. There is a need for an effective public health RSV surveillance system with standard laboratory techniques and equipment to better understand the RSV disease age-specific incidence, seasonality, risk factors and RSV burden among patients in communities in Cameroon.
Journal Article
Assessment of health care workers preparedness to epidemics: A case of Ebola virus disease preparedness in private hospitals in Kampala, Uganda
by
Nakubulwa, Susan
,
Ankunda, Collins
,
Kanyesigye, Stuart Martin
in
Adult
,
Case management
,
Cross-Sectional Studies
2024
Introduction: Unrecognized Ebola Virus Disease (EVD) can lead to multiple chains of transmissions if the first caretakers are not trained and prepared. This study aimed to assess healthcare workers (HCWs) preparedness in private hospitals located in Kampala, to detect, respond and prevent EVD. Methodology: A descriptive cross-sectional study was carried out among HCWs in direct clinical care provision in four private hospitals, and in one Ebola Treatment Unit (ETU) using a self-administered questionnaire from March to June 2020. Results: 222 HCWs agreed to participate aged from 19 to 64 years and with 6 months to 38 years of practice where most were nurses (44%). 3/5 hospitals did not have written protocols on EVD case management, and only one (ETU) had an exclusive emergency team. 59% were not sure whether contact tracing was taking place. Private hospitals were not included in EVD trainings organized by the Ministry of Health (MoH). In addition, HCWs in private hospitals were not empowered by the MoH to take part in EVD case management. Despite these shortcomings, only 66% of HCWs showed an interest to be immunized. Knowledge about potential Ebola vaccines was generally poor. Conclusions: In Kampala, Uganda, establishment of a more comprehensive preparedness and response strategy for EVD outbreaks is imperative for HCWs in private facilities, including a wide vaccination educational program on Ebola vaccination. The findings from this study if addressed will likely improve the preparedness and management of future Ebola outbreaks in Uganda.
Journal Article
Assessment of immunization data management practices in Cameroon: unveiling potential barriers to immunization data quality
by
Zambou, Vouking Marius
,
Nnang, Nadege Edwidge
,
Adidja, Amani
in
Antigens
,
Cameroon - epidemiology
,
Child
2023
Background
One crucial obstacle to attaining universal immunization coverage in Sub-Saharan Africa is the paucity of timely and high-quality data. This challenge, in part, stems from the fact that many frontline immunization staff in this part of the world are commonly overburdened with multiple data-related responsibilities that often compete with their clinical tasks, which in turn could affect their data collection practices. This study assessed the data management practices of immunization staff and unveiled potential barriers impacting immunization data quality in Cameroon.
Methods
A descriptive cross-sectional study was conducted, involving health districts and health facilities in all 10 regions in Cameroon selected by a multi-stage sampling scheme. Structured questionnaires and observation checklists were used to collect data from Expanded Program of Immunization (EPI) staff, and data were analyzed using STATA VERSION 13.0 (StataCorp LP. 2015. College Station, TX).
Results
A total of 265 facilities in 68 health districts were assessed. There was limited availability of some data recording tools like vaccination cards (43%), maintenance registers (8%), and stock cards (57%) in most health facilities. Core data collection tools were incompletely filled in a significant proportion of facilities (37% for registers and 81% for tally sheets). Almost every health facility (89%) did not adhere to the recommendation of filling tally sheets during vaccination; the filling was instead done either before (51% of facilities) or after (25% of facilities) vaccinating several children. Moreso, about 8% of facilities did not collect data on vaccine administration. About a third of facilities did not collect data on stock levels (35%), vaccine storage temperatures (21%), and vaccine wastage (39%).
Conclusion
Our findings unveil important gaps in data collection practices at the facility level that could adversely affect Cameroon’s immunization data quality. It highlights the urgent need for systematic capacity building of frontline immunization staff on data management capacity, standardizing data management processes, and building systems that ensure constant availability of data recording tools at the facility level.
Journal Article
Novel Oral Polio Vaccine Type 2 Use for Polio Outbreak Response: A Global Effort for a Global Health Emergency
by
Toher, Margaret
,
Azhari, Adriansjah
,
Bandyopadhyay, Ananda Sankar
in
Clinical trials
,
Consortia
,
Control
2024
A sharp rise in circulating vaccine-derived poliovirus type 2 (cVDPV2) outbreaks in the years following the cessation of routine use of poliovirus type 2-containing oral polio vaccine and the trend of seeding new emergences with suboptimal vaccination response during the same time-period led to the accelerated development of the novel oral polio vaccine type 2 (nOPV2), a vaccine with enhanced genetic stability and lower likelihood of reversion to neuroparalytic variants compared to its Sabin counterpart. In November 2020, nOPV2 became the first vaccine to be granted an Emergency Use Listing (EUL) by the World Health Organization (WHO) Prequalification Team (PQT), allowing close to a billion doses to be used by countries within three years after its first rollout and leading to full licensure and WHO prequalification (PQ) in December 2023. The nOPV2 development process exemplifies how scientific advances and innovative tools can be applied to combat global health emergencies in an urgent and adaptive way, building on a collaborative effort among scientific, regulatory and implementation partners and policymakers across the globe.
Journal Article