Background. Monovalent rotavirus vaccine was introduced in the routine public health immunization program in Lusaka, Zambia, in January 2012 and was rolled out countrywide in November 2013. We examined the effect of rotavirus vaccination on hospitalization for all-cause acute gastroenteritis (AGE) and rotavirus-specific AGE at a large referral hospital in Lusaka.
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26 February 2024 in International Journal of Infectious Diseases
Tuberculosis (TB) remains a leading cause of death globally and is estimated to have caused 1.3 million deaths worldwide in 2022. Approximately one quarter of the world's population are infected with Mycobacterium tuberculosis, of whom up to 10% will progress to developing active TB disease. Achieving the WHO End TB Strategy targets of a 95% reduction in TB mortality and a 90% reduction in TB incidence worldwide, by 2035, remains a daunting task. The continuing spread of multi-drug resistant TB adds another obstacle to achieving global TB control. Larger funding pledges coupled with technological advances have recently enabled enhancement of TB vaccine development efforts. These are yielding a pipeline of over 17 products currently in different stages of clinical trials. Emerging promising phase 1 and 2 trials' results and advancement to phase 3 trials have necessitated "vaccine preparedness" in parallel so that a smooth transition from any positive clinical trials' results to phase 4 evaluation and implementation into policy and practice can follow. Promotion of a human-rights-based approach which recognizes and upholds the fundamental rights of all affected by the disease, is essential to ensure universal access to quality TB vaccines regardless of their background or personal circumstances.
Rotavirus vaccines, Rotarix and RotaTeq, are increasingly being introduced in national immunization programmes in Africa to prevent severe dehydrating acute gastroenteritis. A low-level risk of intussusception has been associated with rotavirus vaccines. We reviewed published data on intussusception in children <2 years of age in Africa. PubMed electronic database search was used to retrieve papers published on intussusception. The search was further refined to identify surveillance reports and case series conducted from 1980 to 2014, with at least 25 cases. The initial search identified 34 studies, and the refined search yielded 16. Intussusception occurred naturally in infants 2–4 months and peaked around 5–8 months of age. Delayed presentation was common and required surgical intervention in 87% (1008 of 1158) of cases with a high CFR, 10–33.7%. In African children, intussusception has been reported infrequently at a young age when the first dose of rotavirus vaccine is administered.
Objective: Although many HIV-infected (HIV+) and HIV-exposed but uninfected (HEU) infants have received live rotavirus vaccines since the WHO recommended universal administration of these vaccines to infants, there has been limited prospective information on their safety and immunogenicity in either group of infants. Design/methods: We performed a randomized, double-blinded, placebo-controlled trial of the safety and immunogenicity of oral pentavalent rotavirus vaccine (RV5) administered to HIV+ and HEU infants in four African countries. Ninety-three percent of HIV+ infants were receiving antiretroviral therapy prior to vaccination. Participants were followed for safety. Immune responses were measured 14 days after three doses of RV5, including serum antirotavirus neutralizing and IgA antibodies, IgA antibody in stool, and antirotavirus memory B and T-cell FluoroSpot. Shedding of RV5 in stool was monitored. Results: A total of 76 HIV+ and 126 HEU infants were enrolled from 2009 to 2013. No significant differences were found in adverse event rates, including grade 3 events, between RV5 and placebo recipients, for either HIV+ or HEU infants. The proportion of antirotavirus IgA responders (at least three-fold increase from baseline) after RV5 administration was 81% in both HIV+ and HEU infants, which was approximately 2.5-fold higher than in placebo recipients (P < 0.001). Neutralizing antibody responses to three of five serotypes were significantly higher after RV5 regardless of HIV status, and those of HIV+ infants were equal or greater than responses of HEU infants to all five serotypes. Only one HIV+ RV5 recipient had RV5 isolated from stool. Conclusion: RV5 was immunogenic in both HIV+ and HEU infants and no safety signals were observed.
1 January 2014 in The Pediatric Infectious Disease Journal
Background: Intussusception, a rare adverse event associated with rotavirus vaccines in some settings, is a common cause of intestinal obstruction in infants and toddlers globally with a peak age of 4–6 months. This age group may overlap with the extended age of administering rotavirus vaccine. Methods: A retrospective (January 2007 to June 2009) and prospective (July 2009 to June 2012) survey was conducted in 9 Zambian hospitals. Children between 0 and 24 months who were operated on for intestinal obstruction/intussusception were identified in theatre log books. In the latter part of the survey, patients were recruited prospectively. Demographic, clinical and surgical data from hospital files were collected for each patient. Results: One-hundred and five children were identified to have undergone surgery for intussusceptions. Many were boys 57.6% (57/99). Of those with complete data, intussusception was common in infants 86.9% (86/99) and many children (68.0%) were between 3 and 8 months of age with a peak age of 5–6 months. Lusaka had the highest number of children with intussusception with an estimated annual incidence rate of 12/100,000 in children <2 years of age. The overall case fatality rate was very high 33.7% (31/92). Conclusion: Intussusception was common in infants with a peak age of 5–6 months, and of particular concern is the group of 2–4 months the age of rotavirus vaccination. The estimated incidence rate of 12/100,000 is an underestimate as many cases may not present for care. The high case fatality rate of 33.7% is due to both delayed presentation and diagnosis in hospital.
A human-porcine reassortant strain, RVA/Human-wt/ZMB/UFS-NGS-MRC-DPRU4723/2014/G5P[6], was identified in a sample collected in 2014 from an unvaccinated 12 month old male hospitalised for gastroenteritis in Zambia. We sequenced and characterised the complete genome of this strain which presented the constellation: G5-P[6]-I1-R1-C1-M1-A8-N1-T1-E1-H1. The genotype A8 is often observed in porcine strains. Phylogenetic analyses showed that VP6, VP7, NSP2, NSP4, and NSP5 genes were closely related to cognate gene sequences of porcine strains (e.g., RVA/Pig-wt/CHN/DZ-2/2013/G5P[X] for VP7) from the NCBI database, while VP1, VP3, VP4, and NSP3 were closely related to porcine-like human strains (e.g., RVA/Human-wt/CHN/E931/2008/G4P[6] for VP1, and VP3). On the other hand, the origin of the VP2 was not clear from our analyses, as it was not only close to both porcine (e.g., RVA/Pig-tc/CHN/SWU-1C/2018/G9P[13]) and porcine-like human strains (e.g., RVA/Human-wt/LKA/R1207/2009/G4P[6]) but also to three human strains (e.g., RVA/Human-wt/USA/1476/1974/G1P[8]). The VP7 gene was located in lineage II that comprised only porcine strains, which suggests the occurrence of independent porcine-to-human reassortment events. The study strain may have collectively been derived through interspecies transmission, or through reassortment event(s) involving strains of porcine and porcine-like human origin. The results of this study underline the importance of whole-genome characterisation of rotavirus strains and provide insights into interspecies transmissions from porcine to humans.