Efficacy and immunogenicity of two or three dose rotavirus-vaccine regimen in South African children over two consecutive rotavirus-seasons: A randomized, double-blind, placebo-controlled trial

Madhi, Shabir А.; Kirsten, Mari; Louw, Cheryl; P, Bos; Aspinall, Sanet; Bouckenooghe, Alain; Neuzil, Kathleen M.; Steele, A. Duncan

doi:10.1016/j.vaccine.2011.08.080

Cited by 95 publications

(62 citation statements)

References 29 publications

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“…In addition to the differences in observed vaccine efficacy and effectiveness, there are also marked differences in vaccine-elicited immunity as reported by various vaccine-elicited antibody titers following rotavirus immunization (13)(14)(15)(16)(17)(18). A number of hypotheses have been put forward to explain the differences in efficacy and vaccineelicited immunity between HIC and LMIC.…”

Section: Introductionmentioning

confidence: 99%

“…However, there is consistent evidence from clinical trials that RV have lower efficacies in low-and middle-income countries (LMIC): vaccine efficacies are 80 to 90% in high-income countries (HIC) and 40 to 60% in LMIC (3-8). Indeed, there is growing evidence from vaccine effectiveness studies emerging from the field that in real-life use, vaccine effectiveness is also consistently lower in LMIC (9-12).In addition to the differences in observed vaccine efficacy and effectiveness, there are also marked differences in vaccine-elicited immunity as reported by various vaccine-elicited antibody titers following rotavirus immunization (13)(14)(15)(16)(17)(18). A number of hypotheses have been put forward to explain the differences in efficacy and vaccineelicited immunity between HIC and LMIC.…”

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confidence: 99%

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Contribution of Maternal Immunity to Decreased Rotavirus Vaccine Performance in Low- and Middle-Income Countries

Mwila

Chilengi

Simuyandi

et al. 2017

Clin Vaccine Immunol

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The role of maternal immunity, received by infants either transplacentally or orally from breast milk, in rotavirus vaccine (RV) performance is evaluated here. Breastfeeding withholding has no effect on vaccine responses, but higher levels of transplacental rotavirus-specific IgG antibody contribute to reduced vaccine seroconversion. The gaps in knowledge on the factors associated with low RV efficacy in low-and middle-income countries (LMIC) remain, and further research is needed to shed more light on these issues. KEYWORDS immunization, low-and middle-income countries, maternal, rotavirus D espite the progress seen with the global introduction of rotavirus vaccines (RV), diarrhea is still a leading cause of death in children under the age of 5 years, and a substantial proportion of disease cases are still attributable to rotavirus infection. The latest estimates show that approximately 215,000 children die each year from rotavirusassociated diarrhea, and approximately 56% of these deaths are in sub-Saharan Africa (1). The World Health Organization (WHO) recommended the introduction of oral RV into national immunization programs (2), and many countries have heeded this call. As of September 2016, the WHO lists 86 countries as having included RV in their national immunization programs, and 6 more are in the course of doing so in 2016 (www.who.int/immunization/monitoring_surveillance/VaccineIntroStatus.pptx). Approximately 50% of the countries in Africa and Asia, over 80% of those in North America, South America, and Australia, and approximately 40% of those in Europe have introduced RV. Following RV introduction, there was a notable reduction in the number of deaths due to diarrhea (1). However, there is consistent evidence from clinical trials that RV have lower efficacies in low-and middle-income countries (LMIC): vaccine efficacies are 80 to 90% in high-income countries (HIC) and 40 to 60% in LMIC (3-8). Indeed, there is growing evidence from vaccine effectiveness studies emerging from the field that in real-life use, vaccine effectiveness is also consistently lower in LMIC (9-12).In addition to the differences in observed vaccine efficacy and effectiveness, there are also marked differences in vaccine-elicited immunity as reported by various vaccine-elicited antibody titers following rotavirus immunization (13)(14)(15)(16)(17)(18). A number of hypotheses have been put forward to explain the differences in efficacy and vaccineelicited immunity between HIC and LMIC. The hypotheses include (i) maternal factors (such as interference from transplacental antibodies and antibody and nonantibody breast milk components [13,[19][20][21][22][23] [38,39]). A better understanding of these factors which decrease the efficacy of RV in LMIC may help to inform interventions to improve efficacy and to further reduce the number of child deaths due to rotavirus disease. This review examines the correlations between maternal immune factors and RV responses and their potential effect on vaccine efficacy. NATURAL ROTAVIRUS...

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Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

Contribution of Maternal Immunity to Decreased Rotavirus Vaccine Performance in Low- and Middle-Income Countries

Mwila

Chilengi

Simuyandi

et al. 2017

Clin Vaccine Immunol

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“…Although two safe and effective, live, attenuated oral RV vaccines were licensed for use in humans in 2006, the long-term impact of these vaccines on the reduction of RV-induced severe gastroenteritis, especially in the poorest countries, has not been completely established (12,72). Recent studies have shown lower levels of protection in vaccinated children from developing countries in Asia and Africa, with a higher incidence of RV gastroenteritis in these children compared to vaccinated children in the United States (42,43,60,74). A better understanding of the mechanisms of immune protection after natural infection or vaccination is key to development of more effective third-generation vaccination strategies against RV (3).…”

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confidence: 99%

Human Rotavirus-Specific IgM Memory B Cells Have Differential Cloning Efficiencies and Switch Capacities and Play a Role in Antiviral ImmunityIn Vivo

Narváez

Feng

Vásquez

et al. 2012

J Virol

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Protective immunity to rotavirus (RV) is primarily mediated by antibodies produced by RV-specific memory B cells (RV-mBc).Of note, most of these cells express IgM, but the function of this subset is poorly understood. Here, using limiting dilution assays of highly sort-purified human IgM ؉ mBc, we found that 62% and 21% of total (non-antigen-specific) IgM ؉ and RV-IgM ؉ mBc, respectively, switched in vitro to IgG production after polyclonal stimulation. Moreover, in these assays, the median cloning efficiencies of total IgM ؉ (17%) and RV-IgM ؉ (7%) mBc were lower than those of the corresponding switched (IgG ؉ IgA ؉ ) total (34%) and RV-mBc (17%), leading to an underestimate of their actual frequency. In order to evaluate the in vivo role of IgM ؉ RV-mBc in antiviral immunity, NOD/Shi-scid interleukin-2 receptor-deficient (IL-2R␥null ) immunodeficient mice were adoptively transferred highly purified human IgM ؉ mBc and infected with virulent murine rotavirus. These mice developed high titers of serum human RV-IgM and IgG and had significantly lower levels than control mice of both antigenemia and viremia. Finally, we determined that human RV-IgM ؉ mBc are phenotypically diverse and significantly enriched in the IgM hi IgD low subset. Thus, RV-IgM ؉ mBc are heterogeneous, occur more frequently than estimated by traditional limiting dilution analysis, have the capacity to switch Ig class in vitro as well as in vivo, and can mediate systemic antiviral immunity.

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“…The observation that the field effectiveness of HRV appears to be sustained in the 12-to 23-month age group is in contrast to the vaccine efficacy study conducted in South Africa, where HRV efficacy against severe RVGE appeared to decline in the second year of life (TABLE 3) [40,41].…”

Section: Figure 2)mentioning

confidence: 77%

“…The efficacy study in South Africa was not powered to evaluate efficacy specifically during the second year of follow-up and was further limited by a low attack rate in both the vaccinated and control cohorts, with only nine cases of RVGE detected in a cohort of 686 infants. As a consequence of the low incidence of RVGE in both the placebo and vaccine group, vaccine efficacy in the second year of life could not be accurately determined (estimated vaccine efficacy 40% [95% confidence interval (CI): À204-87]) [41]. Due to its retrospective nature, the case-control study was able to identify 151 cases in children aged 12-23 months, allowing for statistically significant betweengroup differences to be determined between the RV group and uninfected controls [39].…”

Section: Figure 2)mentioning

confidence: 99%

Human rotavirus vaccine (Rotarix): focus on effectiveness and impact 6 years after first introduction in Africa

O’Ryan¹,

Giaquinto²,

Benninghoff³

2015

Expert Review of Vaccines

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A decade after licensure of the human rotavirus vaccine (HRV), a wealth of evidence supports a reduction of rotavirus (RV) gastroenteritis-associated mortality and hospitalizations following HRV inclusion in national immunization programs. Nevertheless, the majority of real-world data has been generated in high- or middle-income settings. Clinical efficacy trials previously indicated RV vaccine performance may be lower in less-developed countries compared with wealthier counterparts. Using recently published data from Africa, we examine the effectiveness and impact of HRV in resource-deprived areas, exploring whether vaccine performance differs by socioeconomic setting and the potential underlying factors. HRV vaccine effectiveness in early adopting African countries has proven to be similar or even superior to the efficacy results observed in pre-licensure studies.

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Efficacy and immunogenicity of two or three dose rotavirus-vaccine regimen in South African children over two consecutive rotavirus-seasons: A randomized, double-blind, placebo-controlled trial

Cited by 95 publications

References 29 publications

Contribution of Maternal Immunity to Decreased Rotavirus Vaccine Performance in Low- and Middle-Income Countries

Contribution of Maternal Immunity to Decreased Rotavirus Vaccine Performance in Low- and Middle-Income Countries

Human Rotavirus-Specific IgM Memory B Cells Have Differential Cloning Efficiencies and Switch Capacities and Play a Role in Antiviral ImmunityIn Vivo

Human rotavirus vaccine (Rotarix): focus on effectiveness and impact 6 years after first introduction in Africa

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