China
Africa
Explore chapters and articles related to this topic
Human Gut Microbiota–Transplanted Gn Pig Models for HRV Infection
Published in Lijuan Yuan, Vaccine Efficacy Evaluation, 2022
Rotavirus gastroenteritis-associated deaths are mostly from low-middle-income countries (LMICs) (2013; Tate et al., 2012). Oral vaccines for rotavirus, poliovirus, cholera, and shigellosis are less efficacious in children from LMICs than in children from higher-income countries (Gilmartin and Petri, 2015; Valdez et al., 2014). Specifically, regarding oral rotavirus vaccination, the two commercially available vaccines (RotaTeq® and Rotarix®) only have 39–70% efficacy, with an average of 50–60% efficacy in LMICs; whereas rotavirus vaccines are 80–90% effective in high-income countries (Armah et al., 2010; Gilmartin and Petri, 2015; Glass et al., 2014; Zaman et al., 2010). Differences in rotavirus vaccine efficacy may be due to a combination of factors including environmental enteric dysfunction (EED), variations in the gut microbiome, an altered gut microbiota composition (dysbiosis), high maternal antibody titers transferred through the placenta or breast milk, malnutrition, or influence of concurrent enteropathogens (Becker-Dreps et al., 2015b; Gilmartin and Petri, 2015; Glass et al., 2014; Valdez et al., 2014; Zaman et al., 2010).
Answers
Published in Samar Razaq, Difficult Cases in Primary Care, 2021
Vaccines may be live attenuated, inactivated, polysaccharide vaccines or genetically engineered. Attenuation of a live organism refers to weakening it in a laboratory before using it to stimulate active immunity in the recipient. Usually only one dose is required, as they stimulate a more effective immune response in the recipient. However, second doses are needed for some vaccinations (e.g. measles, mumps and rubella) where a sufficient response is not mounted in all individuals after the first dose. Inactivated vaccines require multiple doses where the first dose merely primes the immune system, with an effective immune response mounted on subsequent doses. Oral polio vaccine (the Sabin vaccine) is live, but in the UK injectable polio (the Salk vaccine) is used, which is inactivated. Rotavirus vaccine has been recently introduced into the routine immunisation schedule in the UK, given at 2 and 3 months of age.
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
Additional vaccines are important to meet the need to vaccinate the global birth cohort and reduce cost. A monovalent neonatal human vaccine strain (RV3-BB) given in neonatal or infant schedules, respectively, with the first dose being a birth dose to neonates, has shown good efficacy in a trial in Indonesia. This strategy of administering a neonatal rotavirus vaccine at birth to target early prevention of rotavirus gastroenteritis may address some of the barriers to global rotavirus vaccination. Several other live-attenuated vaccines are being developed by emerging-market manufacturers.
Impact of a twelve-year rotavirus vaccine program on acute diarrhea mortality and hospitalization in Brazil: 2006-2018
Published in Expert Review of Vaccines, 2020
Myrela Conceição Santos De Jesus, Victor Santana Santos, Luciane Moreno Storti-Melo, Carlos Dornels Freire De Souza, Íkaro Daniel De Carvalho Barreto, Marcelo Vitor Costa Paes, Pablo Amércio Silva Lima, Anna Klara Bohland, Eitan N. Berezin, Ricardo Luiz Dantas Machado, Luis Eduardo Cuevas, Ricardo Queiroz Gurgel
Trends on rotavirus vaccine coverage are shown in Figure 1(a). The lowest vaccine coverage was 46.5% in 2006, and the highest 95.4% in 2015. In Brazil, the vaccine coverage trend remained stable between 2006 and 2018 (APC: 4.4%; 95% CI: −0.3% to 9.2%; P = 0.1) (Table 1). All regions showed an increasing trend in relation to vaccination coverage, despite a slight decline in rates from 2015 (Figure 1(a) and Table 1). The North, Northeast, and Central-West regions showed the largest increases in vaccination, with increases of 6.6%, 5.2%, and 5.4%, respectively. All states showed an increasing trend from 2006 to 2018, excepting the Federal District (APC: 1.8%; 95% CI: −1.2% to 4.9%; P = 0.2), which had a stable trend in vaccination coverage.
Update on vaccination of preterm infants: a systematic review about safety and efficacy/effectiveness. Proposal for a position statement by Italian Society of Pediatric Allergology and Immunology jointly with the Italian Society of Neonatology.
Published in Expert Review of Vaccines, 2019
Elena Chiappini, Chiara Petrolini, Elena Sandini, Amelia Licari, Lorenza Pugni, Fabio A Mosca, Gian Luigi Marseglia
Two studies focused on rotavirus vaccine immunogenicity and effectiveness [45,46]. Omenaca et al. assessed immunogenicity of rotavirus vaccine dosing IgA specific antibody 30–83 days post-dose 2 in a randomized double-blind multicenter-controlled trial. Seroconversion rate was 85.7% in the vaccine group and 16.0% in the placebo group [46]. Effectiveness of rotavirus vaccination was the topic of the study performed by Roué et al. with the aim to evaluate the impact of the pentavalent rotavirus vaccine on the number of hospitalizations for rotavirus diarrhea in preterm infants. A significant decrease in the number of hospitalizations for rotavirus infection in infants younger than 3 years of age in the three epidemic seasons following the vaccine introduction was found [45].
Estimated impact of rotavirus vaccine on hospitalizations and deaths from rotavirus diarrhea among children <5 in Asia
Published in Expert Review of Vaccines, 2018
Eleanor Burnett, Jacqueline E. Tate, Carl D. Kirkwood, E. Anthony S. Nelson, Mathuram Santosham, A. Duncan Steele, Umesh D. Parashar
These findings support consideration of rotavirus vaccine to help alleviate diarrheal disease burden. However, there is still a need to examine ways to improve effectiveness of rotavirus vaccines in medium and high child mortality settings to receive even further benefits from vaccination. As countries in Asia prepare for rotavirus vaccine introduction, this analysis supports the importance of high coverage and strengthening of the immunization systems to deliver childhood vaccines on schedule. In some early introducing countries in other regions, initial rotavirus vaccine coverage lagged behind that of routine infant vaccines recommended for concomitant administration, reducing the potential of the vaccines to impact disease morbidity and mortality [56–58]. Although uptake has been slow in Asia so far, rotavirus vaccines are starting to gain traction in the region. Over the next 5 years, many of these estimated impacts will become real as countries incorporate rotavirus vaccines into their routine immunization programs.