The performance of licensed rotavirus vaccines and the development of a new generation of rotavirus vaccines: a review

Progress in research and development of preventive vaccines for children in China

The infant and child stage is an important stage for the continuation and development of human society. The initial years of life have a lasting impact on a child's future. Children under the age of 5 have an immature immune system, especially infants and young children under 6 months of age. At this stage, the population has a low immunity to pathogen infections, making them vulnerable to bacteria and viruses. Vaccination can enhance the immunity of infants and children to specific diseases, reduce the transmission rate of infectious diseases, and promote the development of global public health. This article summarizes the current application status of Rotavirus (RV) vaccine, Hand-foot -mouth disease (HFMD) vaccine, and Pneumococcal Conjugate Vaccine (PCV) in China, as well as the research progress of clinical trial vaccine, laying a foundation for subsequent vaccine development.

Effectiveness of Pentavalent Rotavirus Vaccine in Shanghai, China: A Test-Negative Design Study

OBJECTIVE

To evaluate vaccine effectiveness (VE) of a live oral pentavalent rotavirus vaccine (RotaTeq, RV5) among young children in Shanghai, China, via a test-negative design study.

STUDY DESIGN

We consecutively recruited children visiting a tertiary children's hospital for acute diarrhea from November 2021 to February 2022. Information on clinical data and rotavirus vaccination was collected. Fresh fecal samples were obtained for rotavirus detection and genotyping. To evaluate VE of RV5 against rotavirus gastroenteritis among young children, unconditional logistic regression models were conducted to compare ORs for vaccination between rotavirus-positive cases and test-negative controls.

RESULTS

A total of 390 eligible children with acute diarrhea were enrolled, including 45 (11.54%) rotavirus-positive cases and 345 (88.46%) test-negative controls. After excluding 4 cases (8.89%) and 55 controls (15.94%) who had received the Lanzhou lamb rotavirus vaccine, 41 cases (12.39%) and 290 controls (87.61%) were included for the evaluation of RV5 VE. After adjustment for potential confounders, the 3-dose RV5 vaccination showed 85% (95% CI, 50%-95%) VE against mild to moderate rotavirus gastroenteritis among children aged 14 weeks to ≤4 years and 97% (95% CI, 83%-100%) VE among children aged 14 weeks to ≤2 years with genotypes G8P8, G9P8, and G2P4 represented 78.95%, 18.42%, and 2.63% of circulation strains, respectively.

CONCLUSIONS

A 3-dose vaccination of RV5 is highly protective against rotavirus gastroenteritis among young children in Shanghai. The G8P8 genotype prevailled in Shanghai after RV5 introduction.

Rotavirus Vaccination of Premature Newborns in the NICU: Evaluation of Vaccination Rates and Safety Based on a Single-Centre Study

Preterm newborns are babies born before the end of the 36th week of gestational life. They are at increased risk of infection and death from infectious diseases. This is due, among other things, to the immaturity of the immune system and the long hospitalisation period. One common infectious disease in the paediatric population is rotavirus (RV) infection. We now have specific vaccines against this pathogen. The aim of this study was to evaluate the safety of rotavirus vaccination in the neonatal intensive care unit (NICU) setting and to determine the tolerance of this vaccine in low- and extremely low-weight children. The study carried out at a single centre, the University Hospital in Kraków, also allowed the assessment of vaccination trends during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. During the observation period, 126 premature newborns received the RV vaccine. We observed no adverse effects, and our analysis shows safety and good tolerance of the vaccine among preterm babies. In addition, we observed an increase in vaccination rates between 2019 and 2021, partly explained by parents' anxiety about infectious diseases in the era of pandemics and partly explained by a change in vaccination policy in Poland and the introduction of refunding for RV vaccination.

[Virus-like particles based on rotavarus A recombinant VP2/VP6 proteins for assessment the antibody immune response by ELISA]

INTRODUCTION

Rotavirus infection is one of the main concerns in infectious pathology in humans, mammals and birds. Newborn piglets or rodents are usually being used as a laboratory model for the evaluation of immunogenicity and efficacy for all types of vaccines against rotavirus A (RVA), and the use of ELISA for the detection of virus-specific antibodies of specific isotype is an essential step of this evaluation.

OBJECTIVE

Development of indirect solid-phase ELISA with VP2/VP6 rotavirus VLP as an antigen to detect and assess the distribution of RVA-specific IgG, IgM and IgA in the immune response to rotavirus A.

MATERIALS AND METHODS

VP2/VP6 rotavirus VLP production and purification, electron microscopy, PAGE, immunoblotting, ELISA, virus neutralization assay.

RESULTS

The study presents the results of development of a recombinant baculovirus with RVA genes VP2-eGFP/VP6, assessment of its infectious activity and using it for VLP production. The morphology of the VP2/VP6 rotavirus VLPs was assessed, the structural composition was determined, and the high antigenic activity of the VLP was established. VLP-based ELISA assay was developed and here we report results for RVA-specific antibody detection in sera of different animals.

CONCLUSION

The developed ELISA based on VP2/VP6 rotavirus VLP as a universal antigen makes it possible to detect separately IgG, IgM and IgA antibodies to rotavirus A, outlining its scientific and practical importance for the evaluation of immunogenicity and efficacy of traditional vaccines against rotavirus A and those under development.

Co-Surveillance of Rotaviruses in Humans and Domestic Animals in Central Uganda Reveals Circulation of Wide Genotype Diversity in the Animals

Rotavirus genotypes are species specific. However, interspecies transmission is reported to result in the emergence of new genotypes. A cross-sectional study of 242 households with 281 cattle, 418 goats, 438 pigs, and 258 humans in Uganda was undertaken between 2013 and 2014. The study aimed to determine the prevalence and genotypes of rotaviruses across co-habiting host species, as well as potential cross-species transmission. Rotavirus infection in humans and animals was determined using NSP3 targeted RT-PCR and ProSpecT Rotavirus ELISA tests, respectively. Genotyping of rotavirus-positive samples was by G- and P-genotype specific primers in nested RT-PCR assays while genotyping of VP4 and VP7 proteins for the non-typeable human positive sample was done by Sanger sequencing. Mixed effect logistic regression was used to determine the factors associated with rotavirus infection in animals. The prevalence of rotavirus was 4.1% (95% CI: 3.0–5.5%) among the domestic animals and 0.8% (95% CI: 0.4–1.5%) in humans. The genotypes in human samples were G9P[8] and P[4]. In animals, six G-genotypes, G3(2.5%), G8(10%), G9(10%), G11(26.8%), G10(35%), and G12(42.5%), and nine P-genotypes, P[1](2.4%), P[4](4.9%), P[5](7.3%), P[6](14.6%), P[7](7.3%), P[8](9.8%), P[9](9.8%), P[10](12.2%), and P[11](17.1%), were identified. Animals aged 2 to 18 months were less likely to have rotavirus infection in comparison with animals below 2 months of age. No inter-host species transmission was identified.

A Clinical Nursing Care Study on the Prevalence of Rotavirus Infection and Acute Diarrhea in Vaccinated Chinese Pediatric Population from 2019-2022

Purpose

To investigate the prevalence of rotavirus infection and acute diarrhea after immunization and further assess the quality of nursing care provided by the nurses to such patients.

Methods

A total of 432 children aged 3–36 months with acute diarrhea between February 2019 and March 2022 were enrolled, and rotavirus testing was performed within 24 h using a rotavirus enzyme immunoassay kit. Clinical characteristics were evaluated, and regression analysis was performed.

Results

Eighty vaccinated children (18.5%) were confirmed to have rotavirus infection out of 432 children. The prevalence of rotavirus positivity was the highest at 20–28 months (22 cases, 24.44%) and 11–19 months age group (27 cases, 22.50%). There is a significant association between rotavirus infection and hygiene score (p = 0.009). Based on the association with quality of nursing care, rotavirus infection was association with “appropriate care” (p = 0.001).

Conclusion

Rotavirus infection was strongly associated with poor hygiene score which may be due to the hygienic nature of the mother and her family. Nursing care assessments revealed a huge gap between nurses and the guardians, which reflects the behavior of Chinese nurses. Thus, an intervention is required by the policymakers for implementing effective strategies of quality nursing for the improvement of the pediatric patients with rotavirus gastroenteritis.

Biolayer Interferometry Analysis for a Higher Throughput Quantification of In-Process Samples of a Rotavirus Vaccine

Rotavirus A infection is a global leading cause of severe acute gastroenteritis associated with life-threatening diarrheal episodes in infants and young children. The disease burden is being reduced, namely due to a wider access to rotavirus vaccines. However, there is a demand to expand rotavirus vaccination programs, and to achieve this, it is critical to improve high-throughput in-process product quality control and vaccine manufacturing monitoring. Here, we present the development of an analytical method for the quantification of rotavirus particles contained in a licensed vaccine. The binding of rotavirus proteins to distinct glycoconjugate receptors and monoclonal antibodies was evaluated using biolayer interferometry analysis, applied on an Octet platform. The antibody strategy presented the best results with a linear response range within 2.5 × 107–1.0 × 108 particles·mL−1 and limits of detection and quantification of 2.5 × 106 and 7.5 × 106 particles·mL−1, respectively. Method suitability for the quantification of in-process samples was shown using samples from different manufacturing stages and their titers were comparable with the approved CCID(50) method. This cell-free method enables a fast and high-throughput analysis, compatible with time constraints during bioprocess development and it is suitable to be adapted to other viral particle-based drug products.

[Synthesis and characterization of human rotavirus A (Reoviridae: Sedoreovirinae: Rotavirus: Rotavirus A) virus-like particles]

INTRODUCTION

Rotavirus infection is the leading cause of acute gastroenteritis among infants. The development of new vaccines against rotavirus A is urgent because the virus has many genotypes, some of which have regional prevalence. Virus-like particles (VLP) is a promising way to create effective and safe vaccine preparations.The purpose of the study is to develop the technology for the production of VLP, containing VP2, VP4, VP6 and VP7 of viral genotypes prevalent on the territory of the Russian Federation, and to give its molecular genetic and virological characteristics.

MATERIAL AND METHODS

The virulent strain Wa G1P[8] of human RV A adapted to MARC-145 cell culture has been used. It was cultured and purified according to the method described by the authors earlier. Standard molecular genetic and cytological methods were used: gene synthesis; cloning into transfer plasmids; recombinant baculoviruses production in Bac-to-Bac expression system; VLP production in the insect cells; centrifugation in sucrose solution; enzyme-linked immunosorbent assay (ELISA); electron microscopy (EM); polyacrylamide gel electrophoresis (SDS-PAGE) and western blot analysis.

RESULTS

VP4 and VP7 of the six most represented in Russia genotypes: G1, G2, G4, G9, P4, P8, as well as VP2 and VP6 were selected for VLP production. Recombinant baculoviruses were obtained with codon frequencies optimized for insect cells. Cabbage loopper (Trichoplusia ni) cell culture was coinfected with different combinations of baculoviruses, and VLP consisting of 2-4 proteins were produced. VLP were purified by centrifugation. The size and morphology of the particles matched the rotavirus A virion (by EM). The presence of rotavirus A proteins in VLP was confirmed by the ELISA, SDS-PAGE and western blot analysis.

CONCLUSION

The technology for the synthesis of three-layer VLP consisting of VP2, VP4, VP6 and VP7 has been developed and optimized. The resulting VLP composition represents 6 serotypes of VP4 and VP7, which are most represented on the territory of Russia, and can be used for vaccine development.