Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 5 de 5
Filter
1.
Drug Saf ; 43(6): 583-593, 2020 06.
Article in English | MEDLINE | ID: mdl-32239447

ABSTRACT

INTRODUCTION: Pharmacovigilance (PV) systems to monitor drug and vaccine safety are often inadequate in sub-Saharan Africa. In Malawi, a PV enhancement initiative was introduced to address major barriers to PV. OBJECTIVE: The objective of this initiative was to improve reporting of adverse events (AEs) by strengthening passive safety surveillance via PV training and mentoring of local PV stakeholders and healthcare providers (HCPs) at their own healthcare facilities (HCFs). METHODS: An 18-month PV training and mentoring programme was implemented in collaboration with national stakeholders, and in partnership with the Ministry of Health, GSK and PATH. Two-day training was provided to Expanded Programme on Immunisation coordinators, identified as responsible for AE reporting, and four National Regulatory Authority representatives. Abridged PV training and mentoring were provided regularly to HCPs. Support was given in upgrading the national PV system. Key performance indicators included the number of AEs reported, transmission of AE forms, completeness of reports, serious AEs reported and timeliness of recording into VigiFlow. RESULTS: In 18 months, 443 HCPs at 61 HCFs were trained. The number of reported AEs increased from 22 (January 2000 to October 2016) to 228 (November 2016 to May 2018), enabling Malawi to become a member of the World Health Organization Programme for International Drug Monitoring. Most (98%) AE report forms contained mandatory information on reporter, event, patient and product, but under 1% were transmitted to the national PV office within 48 h. CONCLUSION: Regular PV training and mentoring of HCPs were effective in enhancing passive safety surveillance in Malawi, but the transmission of reports to the national PV centre requires further improvement.


When a medicine or vaccine is made available for use, healthcare organisations maintain regular surveillance to confirm that the medicinal product is safe and effective. The efficiency of this surveillance depends mainly on the healthcare system and medical practices in place in each country. An important element is an effective procedure for identifying and reporting any unwanted medical occurrences (adverse events) after taking a medicinal product. In countries where regular safety surveillance has not been maintained, it is important to train and mentor healthcare providers on the need to be aware of adverse events and the importance of adhering to safety reporting procedures. GSK and partners conducted a pilot project in Malawi with the aim of improving adverse event reporting by training and mentoring healthcare providers. Training sessions and continuous mentoring were conducted over 18 months, involving 443 healthcare providers at 61 healthcare facilities. There was a large increase in the number of adverse events reported: from 22 in the 16-year period before the project started to 228 during the 18-month project period. This project showed that the training and mentoring programme for healthcare providers was effective in increasing the number of adverse events reported. This enabled Malawi to join the World Health Organization's international safety reporting scheme. Other countries facing similar challenges in safety surveillance systems could benefit from a similar approach.


Subject(s)
Adverse Drug Reaction Reporting Systems , Drug-Related Side Effects and Adverse Reactions/epidemiology , Health Personnel/education , Pharmacovigilance , Africa South of the Sahara , Health Personnel/organization & administration , Humans , Malawi , Mentoring , Pilot Projects
2.
Vaccine ; 38(4): 897-906, 2020 01 22.
Article in English | MEDLINE | ID: mdl-31708182

ABSTRACT

BACKGROUND: We assessed the safety and immunogenicity of the RTS,S/AS01 malaria vaccine in a subset of children identified as HIV-infected during a large phase III randomized controlled trial conducted in seven sub-Saharan African countries. METHODS: Infants 6-12 weeks and children 5-17 months old were randomized to receive 4 RTS,S/AS01 doses (R3R group), 3 RTS,S/AS01 doses plus 1 comparator vaccine dose (R3C group), or 4 comparator vaccine doses (C3C group) at study months 0, 1, 2 and 20. Infants and children with WHO stage III/IV HIV disease were excluded but HIV testing was not routinely performed on all participants; our analyses included children identified as HIV-infected based on medical history or clinical suspicion and confirmed by polymerase chain reaction or antibody testing. Serious adverse events (SAEs) and anti-circumsporozoite (CS) antibodies were assessed. RESULTS: Of 15459 children enrolled in the trial, at least 1953 were tested for HIV and 153 were confirmed as HIV-infected (R3R: 51; R3C: 54; C3C: 48). Among these children, SAEs were reported for 92.2% (95% CI: 81.1-97.8) in the R3R, 85.2% (72.9-93.4) in the R3C and 87.5% (74.8-95.3) in the C3C group over a median follow-up of 39.3, 39.4 and 38.3 months, respectively. Fifteen HIV-infected participants in each group (R3R: 29.4%, R3C: 27.8%, C3C: 31.3%) died during the study. No deaths were considered vaccination-related. In a matched case-control analysis, 1 month post dose 3 anti-CS geometric mean antibody concentrations were 193.3 EU/mL in RTS,S/AS01-vaccinated HIV-infected children and 491.5 EU/mL in RTS,S/AS01-vaccinated immunogenicity controls with unknown or negative HIV status (p = 0.0001). CONCLUSIONS: The safety profile of RTS,S/AS01 in HIV-infected children was comparable to that of the comparator (meningococcal or rabies) vaccines. RTS,S/AS01 was immunogenic in HIV-infected children but antibody concentrations were lower than in children with an unknown or negative HIV status. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov: NCT00866619.


Subject(s)
HIV Infections/epidemiology , Malaria Vaccines/administration & dosage , Malaria, Falciparum/prevention & control , Vaccination , Vaccines, Synthetic/administration & dosage , Africa South of the Sahara , Case-Control Studies , Double-Blind Method , Female , Humans , Immunogenicity, Vaccine , Infant , Malaria Vaccines/adverse effects , Malaria Vaccines/immunology , Male , Vaccines, Synthetic/adverse effects , Vaccines, Synthetic/immunology
3.
Lancet Infect Dis ; 19(8): 821-832, 2019 08.
Article in English | MEDLINE | ID: mdl-31300331

ABSTRACT

BACKGROUND: Results from a previous phase 3 study showed efficacy of the RTS,S/AS01 vaccine against severe and clinical malaria in children (in 11 sites in Africa) during a 3-4-year follow-up. We aimed to investigate malaria incidence up to 7 years postvaccination in three of the sites of the initial study. METHODS: In the initial phase 3 study, infants aged 6-12 weeks and children aged 5-17 months were randomly assigned (1:1:1) to receive four RTS,S/AS01 doses (four-dose group), three RTS,S/AS01 doses and a comparator dose (three-dose group), or four comparator doses (control group). In this open-label extension study in Korogwe (Tanzania), Kombewa (Kenya), and Nanoro (Burkina Faso), we assessed severe malaria incidences as the primary outcome for 3 additional years (January, 2014, to December, 2016), up to 6 years (younger children) or 7 years (older children) postprimary vaccination in the modified intention-to-treat population (ie, participants who received at least one dose of the study vaccine). As secondary outcomes, we evaluated clinical malaria incidences and serious adverse events. This trial is registered with ClinicalTrials.gov, number NCT02207816. FINDINGS: We enrolled 1739 older children (aged 5-7 years) and 1345 younger children (aged 3-5 years). During the 3-year extension, 66 severe malaria cases were reported, resulting in severe malaria incidence of 0·004 cases per person-years at risk (PPY; 95% CI 0-0·033) in the four-dose group, 0·007 PPY (0·001-0·052) in the three-dose group, and 0·009 PPY (0·001-0·066) in the control group in the older children category and a vaccine efficacy against severe malaria that did not contribute significantly to the overall efficacy (four-dose group 53·7% [95% CI -13·7 to 81·1], p=0·093; three-dose group 23·3% [-67·1 to 64·8], p=0·50). In younger children, severe malaria incidences were 0·007 PPY (0·001-0·058) in the four-dose group, 0·007 PPY (0·001-0·054) in the three-dose group, and 0·011 PPY (0·001-0·083) in the control group. Vaccine efficacy against severe malaria also did not contribute significantly to the overall efficacy (four-dose group 32·1% [-53·1 to 69·9], p=0·35; three-dose group 37·6% [-44·4 to 73·0], p=0·27). Malaria transmission was still occurring as evidenced by an incidence of clinical malaria ranging from 0·165 PPY to 3·124 PPY across all study groups and sites. In older children, clinical malaria incidence was 1·079 PPY (95% CI 0·152-7·662) in the four-dose group, 1·108 PPY (0·156-7·868) in the three-dose group, and 1·016 PPY (0·14-7·213) in the control group. In younger children, malaria incidence was 1·632 PPY (0·23-11·59), 1·563 PPY (0·22-11·104), and 1·686 PPY (0·237-11·974), respectively. In the older age category in Nanoro, clinical malaria incidence was higher in the four-dose (2·444 PPY; p=0·011) and three-dose (2·411 PPY; p=0·034) groups compared with the control group (1·998 PPY). Three cerebral malaria episodes and five meningitis cases, but no vaccine-related severe adverse events, were reported. INTERPRETATION: Overall, severe malaria incidence was low in all groups, with no evidence of rebound in RTS,S/AS01 recipients, despite an increased incidence of clinical malaria in older children who received RTS,S/AS01 compared with the comparator group in Nanoro. No safety signal was identified. FUNDING: GlaxoSmithKline Biologicals SA.


Subject(s)
Malaria Vaccines/administration & dosage , Malaria/epidemiology , Severity of Illness Index , Vaccination , Africa/epidemiology , Child , Child, Preschool , Female , Humans , Incidence , Infant , Malaria Vaccines/immunology , Male
4.
Hum Vaccin Immunother ; 15(10): 2386-2398, 2019.
Article in English | MEDLINE | ID: mdl-31012786

ABSTRACT

A phase III, double-blind, randomized, controlled trial (NCT00866619) in sub-Saharan Africa showed RTS,S/AS01 vaccine efficacy against malaria. We now present in-depth safety results from this study. 8922 children (enrolled at 5-17 months) and 6537 infants (enrolled at 6-12 weeks) were 1:1:1-randomized to receive 4 doses of RTS,S/AS01 (R3R) or non-malaria control vaccine (C3C), or 3 RTS,S/AS01 doses plus control (R3C). Aggregate safety data were reviewed by a multi-functional team. Severe malaria with Blantyre Coma Score ≤2 (cerebral malaria [CM]) and gender-specific mortality were assessed post-hoc. Serious adverse event (SAE) and fatal SAE incidences throughout the study were 24.2%-28.4% and 1.5%-2.5%, respectively across groups; 0.0%-0.3% of participants reported vaccination-related SAEs. The incidence of febrile convulsions in children was higher during the first 2-3 days post-vaccination with RTS,S/AS01 than with control vaccine, consistent with the time window of post-vaccination febrile reactions in this study (mostly the day after vaccination). A statistically significant numerical imbalance was observed for meningitis cases in children (R3R: 11, R3C: 10, C3C: 1) but not in infants. CM cases were more frequent in RTS,S/AS01-vaccinated children (R3R: 19, R3C: 24, C3C: 10) but not in infants. All-cause mortality was higher in RTS,S/AS01-vaccinated versus control girls (2.4% vs 1.3%, all ages) in our setting with low overall mortality. The observed meningitis and CM signals are considered likely chance findings, that - given their severity - warrant further evaluation in phase IV studies and WHO-led pilot implementation programs to establish the RTS,S/AS01 benefit-risk profile in real-life settings.


Subject(s)
Immunization Schedule , Malaria Vaccines/adverse effects , Malaria, Falciparum/prevention & control , Africa South of the Sahara , Double-Blind Method , Female , Fever/chemically induced , Humans , Incidence , Infant , Malaria Vaccines/immunology , Malaria, Cerebral/mortality , Malaria, Cerebral/prevention & control , Malaria, Falciparum/mortality , Male , Meningitis/chemically induced , Plasmodium falciparum , Seizures, Febrile/chemically induced , Vaccination
5.
PLoS One ; 10(7): e0131571, 2015.
Article in English | MEDLINE | ID: mdl-26148007

ABSTRACT

METHODS: In an observer blind, phase 2 trial, 55 adults were randomized to receive one dose of Ad35.CS.01 vaccine followed by two doses of RTS,S/AS01 (ARR-group) or three doses of RTS,S/AS01 (RRR-group) at months 0, 1, 2 followed by controlled human malaria infection. RESULTS: ARR and RRR vaccine regimens were well tolerated. Efficacy of ARR and RRR groups after controlled human malaria infection was 44% (95% confidence interval 21%-60%) and 52% (25%-70%), respectively. The RRR-group had greater anti-CS specific IgG titers than did the ARR-group. There were higher numbers of CS-specific CD4 T-cells expressing > 2 cytokine/activation markers and more ex vivo IFN-γ enzyme-linked immunospots in the ARR-group than the RRR-group. Protected subjects had higher CS-specific IgG titers than non-protected subjects (geometric mean titer, 120.8 vs 51.8 EU/ml, respectively; P = .001). CONCLUSIONS: An increase in vaccine efficacy of ARR-group over RRR-group was not achieved. Future strategies to improve upon RTS,S-induced protection may need to utilize alternative highly immunogenic prime-boost regimens and/or additional target antigens. TRIAL REGISTRATION: ClinicalTrials.gov NCT01366534.


Subject(s)
Malaria Vaccines/immunology , Malaria/immunology , Malaria/prevention & control , Sporozoites/immunology , Antibodies, Protozoan/immunology , Antibody Formation/immunology , CD4-Positive T-Lymphocytes/immunology , Double-Blind Method , Humans , Immunization, Secondary/methods , Immunoglobulin G/immunology , Immunologic Tests/methods , Interferon-gamma/immunology , Vaccination/methods
SELECTION OF CITATIONS
SEARCH DETAIL
...