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Probiotics as HRV Vaccine Adjuvants in Gn Pigs
Published in Lijuan Yuan, Vaccine Efficacy Evaluation, 2022
The dose effects of LA on immune responses to the AttHRV vaccine in pigs may also partly explain why the efficacies of oral rotavirus vaccines are significantly reduced in low-income countries compared to developed countries. The two licensed rotavirus vaccines, RotaTeq and Rotarix have a protective efficacy of >85% against moderate to severe rotavirus gastroenteritis in middle and high-income countries (O'Ryan et al., 2009). However, the protective efficacy of the RotaTeq vaccine is only 39.3% against severe rotavirus gastroenteritis in sub-Saharan Africa (Armah et al., 2010) and 48.3% in developing countries in Asia (Zaman et al., 2010). Rotarix vaccine showed a similar disparity in efficacy in low-income countries in Africa (O'Ryan and Linhares, 2009). In addition to other factors that contribute to the reduction in rotavirus vaccine efficacy (e.g., higher titers of maternal antibodies, malnutrition), during the initial colonization of human infants, exposure to high doses of commensal bacteria (common in countries with lower hygiene standards) would have a suppressive effect on IFN-γ producing T cell responses and promote Treg cell responses, thus leading to the lowered protective immunity after rotavirus vaccination.
Viral infections
Published in Phillip D. Smith, Richard S. Blumberg, Thomas T. MacDonald, Principles of Mucosal Immunology, 2020
Sarah Elizabeth Blutt, Mary K. Estes, Satya Dandekar, Phillip D. Smith
As of April 2018, routine vaccination of infants against rotavirus has been implemented in 95 countries globally. After vaccine implementation, substantial declines in the incidence of severe rotavirus gastroenteritis have been documented, reductions in hospitalization for diarrhea are seen, and childhood deaths from diarrhea are significantly reduced. In several countries, reductions in severe gastroenteritis have been documented in children who are unvaccinated, and in older adults, suggesting that vaccination of young infants indirectly protects these groups by reducing rotavirus transmission in the community, indicating that the vaccines provide some level of herd as well as individual immunity.
Rotavirus
Published in Dongyou Liu, Handbook of Foodborne Diseases, 2018
Lijuan Yuan, Tammy Bui, Ashwin Ramesh
The symptoms of RV illness are not sufficiently distinctive from other causes of gastroenteritis, particularly other viral causes. Diagnosis requires detection of virus particles, viral antigens, or viral nuclear acid (RNA). The advancement of technologies has allowed the development of a wide range of diagnostic tests capable of diagnosing rotavirus gastroenteritis. The methods that have been employed for the detection of RV in human stool samples include electron microscopy (EM), immune EM (IEM), polyacrylamide gel RNA electropherotyping, enzyme-linked immunosorbent assay (ELISA), virus isolation, latex agglutination, RNA-RNA hybridization, reverse transcription-polymerase chain reaction (RT-PCR), real-time RT-PCR, DNA oligonucleotide microarrays, Sanger sequencing, and next-generation sequencing.
All-cause gastroenteritis hospitalisations of children decreased after the introduction of rotavirus vaccine in Stockholm
Published in Infectious Diseases, 2022
Selma Olsson-Åkefeldt, Maria Rotzén-Östlund, Berit Hammas, Margareta Eriksson, Rutger Bennet
In keeping with previous post-licensure studies, we found a decreasing incidence of hospitalisation for both all-cause gastroenteritis and rotavirus gastroenteritis in children <5 years during our ten years of study time. Rotavirus gastroenteritis admissions per 1000 person-years decreased by 78% from 2.9 to 0.65, and all-cause gastroenteritis admissions decreased by 55% from 5.6 to 2.5. Although we detected a slight secular downward trend, most of the decrease was correlated to the vaccine introduction. Studies regarding rotavirus vaccine effectiveness from other countries were summarised in three metanalyses [4–6]. The reduction of hospitalisations was highest in high-income/low-mortality countries with a 66% reduction of rotavirus gastroenteritis hospitalisations and a 38% reduction of all-cause gastroenteritis hospitalisations among children <5 years old [5]. Additional recent studies from other Nordic countries have also found a sustained impact of rotavirus vaccination on hospitalisations for rotavirus gastroenteritis and all-cause gastroenteritis [7,8].
A review of rotavirus vaccine use in Asia and the Pacific regions: challenges and future prospects
Published in Expert Review of Vaccines, 2021
Philippe Buchy, Jing Chen, Xu-Hao Zhang, Bernd Benninghoff, Christa Lee, Gyneth Lourdes Bibera
Rotavirus infection is the leading cause worldwide of acute gastroenteritis (AGE) in children under 5 years of age and causes dehydration of varying degrees [1,2]. Children are at risk of rotavirus infection regardless of widespread implementation of hygiene practices along with exclusive breastfeeding for 6 months, vitamin A supplementation, and access to safe drinking water [3]. Several vaccines have been developed for the prevention of rotavirus gastroenteritis (RVGE) and serve as an effective means to protect children from RVGE [3,4]. Currently, four rotavirus vaccines are prequalified by the World Health Organization (WHO) and available internationally: the monovalent human rotavirus vaccine (HRV; Rotarix, GSK); the pentavalent human-bovine reassortant rotavirus vaccine (HBRV; RotaTeq, Merck & Co. Inc.); the naturally occurring bovine-human reassortant neonatal G9P[11], also called 116E (Rotavac, Bharat Biotech); and the bovine-human reassortant with human G1, G2, G3, G4, and G9 bovine UK G6P[5] backbone (RotaSiil, Serum Institute of India Ltd) [4].
An overview of rotavirus vaccination programs in developing countries
Published in Expert Review of Vaccines, 2020
Benjamin D. Hallowell, Jacqueline Tate, Umesh Parashar
When looking at all countries, previous work has found that at 5 USD per dose, the cost-effectiveness of rotavirus vaccine per disability-adjusted life year (DALY) averted in low, low-middle, and upper-middle-income countries was 88, USD 291, USD, and 329 USD USD, respectively, [66]. Debellut et al. evaluated the potential impact and cost-effectiveness of rotavirus vaccination in 73 Gavi eligible or formerly eligible countries from 2018 to 2027 [67]. This work found that rotavirus vaccine would prevent 158.6 million cases of rotavirus gastroenteritis, 80.7 million outpatient visits, 7.9 million hospitalizations and 576,567 deaths over the 10-year period, and in turn, would avert 14.7 million DALYs [67]. For all countries included in the analysis the cost-effectiveness on average was 325 USD per DALY averted for the entire time period, ranging from a low of 195 USD for countries in the African region to a high of 1158 USD for countries in the Americas [67]. In this analysis, the cost per DALY averted was on average was 0.16 times a country’s GDP per capita (GDP used as the threshold for DALY cost-effectiveness), four countries, however, did have costs exceeding 1.0 times GDP per capita, including; Armenia, Honduras, Moldova, and Ukraine. This is likely due to the fact that these countries are entirely self-financing their rotavirus vaccine purchases [67]. Of note, other studies have occasionally found rotavirus vaccine not to be cost effective, but this generally occurs when only direct medical costs are considered, and not those incurred by the family or society [18].