Established and new rotavirus vaccines: a comprehensive review for healthcare professionals

Health economic evaluation of 2-dose and 3-dose rotavirus vaccines in children below 5 years of age in Morocco

Following the introduction of rotavirus vaccination into the Moroccan National Immunization Program, the prevalence of the disease has decreased by nearly 50%. However, evidence on the economic value of rotavirus vaccinations in Morocco is limited. This health economic analysis evaluated, from both country payer and societal perspectives, the costs and the cost-effectiveness of three rotavirus vaccines using a static, deterministic, population model in children aged < 5 years in Morocco. Included vaccines were HRV (2-dose schedule), HBRV (3-dose schedule) and BRV-PV 1-dose vial (3-dose schedule). One-way and probabilistic sensitivity analyses were conducted to assess the impact of uncertainty in model inputs. The model predicted that vaccination with HRV was estimated to result in fewer rotavirus gastroenteritis events (-194 homecare events, -57 medical visits, -8 hospitalizations) versus the 3-dose vaccines, translating into 7 discounted quality-adjusted life years gained over the model time horizon. HRV was associated with lower costs versus HBRV from both the country payer (-$1.8 M) and societal (-$4.1 M) perspectives, and versus BRV-PV 1-dose vial from the societal perspective (-$187,000), dominating those options in the cost-effectiveness analysis. However, costs of BRV-PV 1-dose vial were lower than HRV from the payer perspective, resulting in an ICER of approximately $328,376 per QALY, above the assumed cost effectiveness threshold of $3,500. Vaccination with a 2-dose schedule of HRV may be a cost-saving option and could lead to better health outcomes for children in Morocco versus 3-dose schedule rotavirus vaccines.

Biotechnological Interventions for the Production of Subunit Vaccines Against Group A Rotavirus

Group A rotavirus (RVA) is a major cause of severe gastroenteritis in infants and young children globally, despite the availability of live-attenuated vaccines. Challenges such as limited efficacy in low-income regions, safety concerns for immunocompromised individuals, and cold-chain dependency necessitate alternative vaccine strategies. Subunit vaccines, which use specific viral proteins to elicit immunity, provide a safer and more adaptable approach. This review highlights biotechnological advancements in producing subunit vaccines, focusing on recombinant expression systems like bacterial, yeast, insect, mammalian, and plant-based platforms for scalable and cost-effective production of viral proteins. Key innovations include molecular engineering, adjuvant development, and delivery system improvements to enhance vaccine immunogenicity and efficacy. Subunit vaccines and virus-like particles expressed in various systems have demonstrated promising preclinical and clinical results, with some candidates nearing commercial readiness. Reverse vaccinology, combined with Artificial Intelligence and Machine Learning, is driving the development of innovative multiepitope vaccines and antivirals. Strategies such as passive immunization, single-chain antibodies, immunobiotics, and novel antivirals are also explored as alternative management options. The review also underscores advanced genome editing and reverse genetics approaches to improve vaccine design and antiviral therapies. These biotechnological interventions offer hope for equitable and effective control of rotavirus diarrhea, particularly in resource-limited settings, and represent significant progress toward addressing current vaccine limitations.

Mannose and Lactobionic Acid in Nasal Vaccination: Enhancing Antigen Delivery via C-Type Lectin Receptors

BACKGROUND/OBJECTIVES

Nasal vaccines are a promising strategy for enhancing mucosal immune responses and preventing diseases at mucosal sites by stimulating the secretion of secretory IgA, which is crucial for early pathogen neutralization. However, designing effective nasal vaccines is challenging due to the complex immunological mechanisms in the nasal mucosa, which must balance protection and tolerance against constant exposure to inhaled pathogens. The nasal route also presents unique formulation and delivery hurdles, such as the mucous layer hindering antigen penetration and immune cell access.

METHODS

This review focuses on cutting-edge approaches to enhance nasal vaccine delivery, particularly those targeting C-type lectin receptors (CLRs) like the mannose receptor and macrophage galactose-type lectin (MGL) receptor. It elucidates the roles of these receptors in antigen recognition and uptake by antigen-presenting cells (APCs), providing insights into optimizing vaccine delivery.

RESULTS

While a comprehensive examination of targeted glycoconjugate vaccine development is outside the scope of this study, we provide key examples of glycan-based ligands, such as lactobionic acid and mannose, which can selectively target CLRs in the nasal mucosa.

CONCLUSIONS

With the rise of new viral infections, this review aims to facilitate the design of innovative vaccines and equip researchers, clinicians, and vaccine developers with the knowledge to enhance immune defenses against respiratory pathogens, ultimately protecting public health.

Molecular Design of Encapsulin Protein Nanoparticles to Display Rotavirus Antigens for Enhancing Immunogenicity

Rotavirus considerably threatens global health, particularly for children <5 years. Current, licensed oral attenuated vaccine formulations have limitations including insufficient efficacy in children in low- and middle-income countries, warranting urgent development of novel vaccines with improved efficacy and safety profiles. Herein, we present a novel approach utilizing an encapsulin (ENC) nanoparticle (NP)-based non-replicating rotavirus vaccine. ENC, originating from bacteria, offers a self-assembling scaffold that displays rotavirus VP8* antigens on its surface. To enhance the correct folding and soluble expression of monomeric antigens and their subsequent assembly into NP, we adopted an RNA-interacting domain (RID) of mammalian transfer RNA synthetase as an expression tag fused to the N-terminus of the ENC-VP8* fusion protein. Using the RID-ENC-VP8* tripartite modular design, insertion of linkers of appropriate length and sequence and the universal T cell epitope P2 remarkably improved the production yield and immunogenicity. Cleavage of the RID rendered a homogenous assembly of ENC-P2-VP8* into protein NPs. Immunization with ENC-P2-VP8* induced markedly higher levels of VP8*-specific antibodies and virus neutralization titers in mice than those induced by P2-VP8* without ENC. Altogether, these results highlight the potential of the designed ENC NP-based rotavirus vaccine as an effective strategy against rotavirus disease to address global health challenges.

Rotavirus vaccination is a protective factor for adverse outcomes in primary intussusception: a single-center retrospective study

Background

The clinical features and prognosis of intussusception in children vaccinated against rotavirus were undefined. Hence, we conducted the study to explore the clinical characteristics and outcomes of primary intussusception patients who received rotavirus vaccine.

Methods

A single-center retrospective study was performed in 327 primary intussusception patients between January 2019 and December 2021. Of these, 168 were vaccinated against rotavirus and 159 were not, the latter serving as the control group. Data on patients' clinical characteristics, commonly used inflammatory biomarkers, treatment, and outcomes were collected and evaluated.

Results

Most of the vaccination group received pentavalent rotavirus vaccine produced by Merck, USA (89.88%). There were no differences in demographic characteristics, time from onset to hospital attendance, clinical symptoms and signs between the vaccination group and the control group. The success rate of air enema reduction in the vaccination group was higher than that in the control group (98.21% vs. 88.68%, q=0.01). The vaccination group had lower rates of surgery and complication (1.79% vs. 11.32%, q=0.008; 2.98% vs. 12.58%, q=0.006). Both platelet-lymphocyte ratio (PLR) and C-reactive protein (CRP) levels were lower in the vaccinated group (q=0.02, q=0.004). Higher CRP level [odds ratio (OR): 1.635; 95% confidence interval (CI): 1.248-2.143; P=0.006] and the longer time from onset to hospital attendance (OR: 3.040; 95% CI: 2.418-12.133; P=0.01) were associated with increased adverse events. Rotavirus vaccination (OR: 0.527; 95% CI: 0.103-0.751; P=0.02) was associated with a reduction in the probability of adverse events.

Conclusions

Adverse events such as surgery and complications were lower in the vaccination group. Rotavirus vaccination was an independent protective factor for adverse events in patients with primary intussusception.

Immunological factors linked to geographical variation in vaccine responses

Vaccination is one of medicine's greatest achievements; however, its full potential is hampered by considerable variation in efficacy across populations and geographical regions. For example, attenuated malaria vaccines in high-income countries confer almost 100% protection, whereas in low-income regions these same vaccines achieve only 20-50% protection. This trend is also observed for other vaccines, such as bacillus Calmette-Guérin (BCG), rotavirus and yellow fever vaccines, in terms of either immunogenicity or efficacy. Multiple environmental factors affect vaccine responses, including pathogen exposure, microbiota composition and dietary nutrients. However, there has been variable success with interventions that target these individual factors, highlighting the need for a better understanding of their downstream immunological mechanisms to develop new ways of modulating vaccine responses. Here, we review the immunological factors that underlie geographical variation in vaccine responses. Through the identification of causal pathways that link environmental influences to vaccine responsiveness, it might become possible to devise modulatory compounds that can complement vaccines for better outcomes in regions where they are needed most.

Immunogenicity of RV1 and RV5 vaccines administered in standard and interchangeable mixed schedules: a randomized, double-blind, non-inferiority clinical trial in Mexican infants

Introduction

Rotavirus-associated diarrheal diseases significantly burden healthcare systems, particularly affecting infants under five years. Both Rotarix™ (RV1) and RotaTeq™ (RV5) vaccines have been effective but have distinct application schedules and limited interchangeability data. This study aims to provide evidence on the immunogenicity, reactogenicity, and safety of mixed RV1-RV5 schedules compared to their standard counterparts.

Methods

This randomized, double-blind study evaluated the non-inferiority in terms of immunogenicity of mixed rotavirus vaccine schedules compared to standard RV1 and RV5 schedules in a cohort of 1,498 healthy infants aged 6 to 10 weeks. Participants were randomly assigned to one of seven groups receiving various combinations of RV1, and RV5. Standard RV1 and RV5 schedules served as controls of immunogenicity, reactogenicity, and safety analysis. IgA antibody levels were measured from blood samples collected before the first dose and one month after the third dose. Non-inferiority was concluded if the reduction in seroresponse rate in the mixed schemes, compared to the standard highest responding scheme, did not exceed the non-inferiority margin of -0.10. Reactogenicity traits and adverse events were monitored for 30 days after each vaccination and analyzed on the entire cohort.

Results

Out of the initial cohort, 1,365 infants completed the study. Immunogenicity analysis included 1,014 infants, considering IgA antibody titers ≥20 U/mL as seropositive. Mixed vaccine schedules demonstrated non-inferiority to standard schedules, with no significant differences in immunogenic response. Safety profiles were comparable across all groups, with no increased incidence of serious adverse events or intussusception.

Conclusion

The study confirms that mixed rotavirus vaccine schedules are non-inferior to standard RV1 and RV5 regimens in terms of immunogenicity and safety. This finding supports the flexibility of rotavirus vaccination strategies, particularly in contexts of vaccine shortage or logistic constraints. These results contribute to the global effort to optimize rotavirus vaccination programs for broader and more effective pediatric coverage.Clinical trial registration: ClinicalTrials.gov, NCT02193061.

Genomic Analysis of Rwandan G9P[8] Rotavirus Strains Pre- and Post-RotaTeq® Vaccine Reveals Significant Distinct Sub-Clustering in a Post-Vaccination Cohort

Although the introduction of rotavirus vaccines has substantially contributed to the reduction in rotavirus morbidity and mortality, concerns persist about the re-emergence of variant strains that might alter vaccine effectiveness in the long term. The G9 strains re-emerged in Africa during the mid-1990s and have more recently become predominant in some countries, such as Ghana and Zambia. In Rwanda, during the 2011 to 2015 routine surveillance period, G9P[8] persisted during both the pre- and post-vaccine periods. The pre-vaccination cohort was based on the surveillance period of 2011 to 2012, and the post-vaccination cohort was based on the period of 2013 to 2015, excluding 2014. The RotaTeq® vaccine that was first introduced in Rwanda in 2012 is genotypically heterologous to Viral Protein 7 (VP7) G9. This study elucidated the whole genome of Rwandan G9P[8] rotavirus strains pre- and post-RotaTeq® vaccine introduction. Fecal samples from Rwandan children under the age of five years (pre-vaccine n = 23; post-vaccine n = 7), conventionally genotyped and identified as G9P[8], were included. Whole-genome sequencing was then performed using the Illumina® MiSeq platform. Phylogenetic analysis and pair-wise sequence analysis were performed using MEGA6 software. Distinct clustering of three post-vaccination study strains was observed in all 11 gene segments, compared to the other Rwandan G9P[8] study strains. Specific amino acid differences were identified across the gene segments of these three 2015 post-vaccine strains. Important amino acid differences were identified at position N242S in the VP7 genome segment of the three post-vaccine G9 strains compared to the other G9 strains. This substitution occurs at a neutralization epitope site and may slightly affect protein interaction at that position. These findings indicate that the Rwandan G9P[8] strains revealed a distinct sub-clustering pattern among post-vaccination study strains circulating in Rwanda, with changes at neutralization epitopes, which may play a role in neutralization escape from vaccine candidates. This emphasizes the need for continuous whole-genome surveillance to better understand the evolution and epidemiology of the G9P[8] strains post-vaccination.

[Study of the safety and immunogenicity of VLP-based vaccine for the prevention of rotavirus infection in neonatal minipig model]

INTRODUCTION

In Russia, almost half of the cases of acute intestinal infections of established etiology in 2022 are due to rotavirus infection (RVI). There is no specific treatment for rotavirus gastroenteritis. There is a need to develop modern, effective and safe vaccines to combat rotavirus infection that are not capable of multiplying (replicating) in the body of the vaccinated person. A promising approach is to create vaccines based on virus-like particles (VLPs).

OBJECTIVE

Study of the safety and immunogenicity of a vaccine against rotavirus infection based on virus-like particles of human rotavirus A in newborn minipigs with multiple intramuscular administration.

MATERIALS AND METHODS

Newborn minipigs were used as an animal model in this study. The safety of the tested vaccine was assessed based on thermometry data, clinical examination, body weight gain, clinical and biochemical blood parameters, as well as necropsy and histological examination. When studying the immunogenic properties of the Gam-VLP-rota vaccine in doses of 30 and 120 µg, the cellular, humoral and secretory immune response was studied.

RESULTS

The results of assessing the general condition of animals during the immunization period, data from clinical, laboratory and pathomorphological studies indicate the safety of the vaccine against human rotavirus infection based on VLP (Gam-VLP-rota) when administered three times intramuscularly. Good local tolerance of the tested vaccine was demonstrated. The results of the assessment of humoral immunity indicate the formation of a stable immune response after three-time immunization with Gam-VLP-rota, stimulation of the production of antigen-specific IgG antibodies and their functional activity to neutralize human rotavirus A. It was shown that following the triple immunization with the minimum tested concentration of 30 µg/dose, animals developed a cell-mediated immune response. The results of the IgA titer in blood serum and intestinal lavages indicate the formation of both a systemic immunological response and the formation of specific secretory immunity to human rotavirus A.

CONCLUSION

Thus, three-time intramuscular immunization of minipigs with the Gam-VLP-rota vaccine forms stable protective humoral and cellular immunity in experimental animals. Evaluated vaccine is safe and has good local tolerability.

Human rotavirus strains circulating among children in the capital of China (2018-2022)_ predominance of G9P[8] and emergence ofG8P[8]

OBJECTIVE

This study aimed to update the genetic diversity of Rotavirus (RV) infections in children under five years old in Beijing, China.

METHODS

A 5-year active hospital-based surveillance for sporadic acute gastroenteritis (AGE) from January 2018 to December 2022 in the capital of China was performed. A total of 748 fecal samples from AGE patients were collected for followed by RV antigen detection by ELSIA, RNA detection by reverse transcription PCR, G/P genotyping and phylogenetic analyzing.

RESULTS

RV antigen was detected in 11.0% of the collected samples, with 54 samples confirmed to be RV RNA positive. G9 and G8 genotypes were identified in 43 (79.6%) and 7 (13.0%) samples, respectively, all of which were allocated to P[8]. The predominant G/P combination was G9P[8] (79.6%), following by G8P[8] (13.0%), G4P[8] (5.6%) and G3P[8] (1.9%). A significant change in G/P-type distribution was observed, with the G9P[8] being predominant from 2018 to 2021, followed by the emergence of an uncommon G8P[8] genotype, which was first reported in 2021 and became predominant in 2022. Blast analysis showed that one G1 isolate had a high similarity of 99.66% on nucleotide acid with RotaTeq vaccine strain with only one amino acid difference L150V. Additionally, one P[8] isolate was clustered into a branch together with RotaTeq vaccine strain G6P[8].

CONCLUSIONS

The study reveals that G8P[8] has become the predominant genotype in pediatric outpatients in China for the first time, indicating a significant change in the composition of RV genetic diversity. The importance of RVA genotyping in surveillance is emphasized, as it provides the basis for new vaccine application and future vaccine efficacy evaluation.

Surveillance of Human Rotaviruses in Wuhan, China (2019-2022): Whole-Genome Analysis of Emerging DS-1-like G8P[8] Rotavirus

Group A rotaviruses (RVAs) are major etiologic agents of gastroenteritis in infants and young children worldwide. To study the prevalence and genetic characteristics of RVAs, a hospital-based surveillance study was conducted in Wuhan, China from June 2019 through May 2022. The detection rates of RVAs were 19.40% (142/732) and 3.51% (8/228) in children and adults, respectively. G9P[8] was the predominant genotype, followed by G8P[8] and G3P[8]. G8P[8] emerged and was dominant in the 2021-2022 epidemic season. The genome constellation of six G8P[8] strains was assigned to G8-P[8]-I2-R2-C2-M2-A2-N2-T2-E2-H2. Phylogenetic analysis revealed that the VP7, VP4, VP2, VP3, NSP1, NSP2, NSP3, and NSP5 genes of these G8P[8] strains clustered closely with those of the G8P[8] strains in Asia and were distant from those of the P[8] and G2P[4] strains simultaneously detected in Wuhan. In contrast, the VP1, VP6, and NSP4 genes were closely related to the typical G2P[4] rotavirus, including those of G2P[4] strains simultaneously detected in Wuhan. The detection rate of RVAs decreased in the COVID-19 pandemic era. It was deduced that the G8P[8] rotaviruses that emerged in China may be reassortants, carrying the VP6, VP1, and NSP4 genes derived from the G2P[4] rotavirus in the backbone of the neighboring DS-1-like G8P[8] strains represented by CAU17L-103.

[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.

Cost-benefit analysis of rotavirus vaccine included in the national immunization program in China

BACKGROUND

Globally, rotavirus is a leading cause of severe acute gastroenteritis among children aged under 5 years and has a significant economic cost. Currently, rotavirus vaccines are only included in the private market in China. This study aimed to assess the cost-benefit of including a three-dose rotavirus vaccine in China's National Immunization Program (NIP).

METHODS

A decision tree Markov model was constructed to evaluate the cost-benefit of universal immunization with three doses of rotavirus vaccine for a 2019 birth cohort of Chinese children. Costs of the universal vaccination program included vaccine price, vaccine wastage, vaccine administration, and indirect costs. All costs were discounted at 3 % per year and converted from 2019 Chinese Yuan to 2019 USD using the 2019 exchange rate.

RESULTS

For the 2019 birth cohort of Chinese infants, inclusion of RotaTeq in NIP was estimated to prevent 5,677,911 cases of rotavirus infection, with net savings of $1.1 billion in total societal costs. A cost of $17.55 per vaccine dose was the threshold at which inclusion of rotavirus vaccine in NIP would be cost-saving.

CONCLUSIONS

Introducing rotavirus vaccine into the China NIP would have significant costs from a societal perspective at the current private market price.

Rotavirus vaccines: progress and new developments

INTRODUCTION

Rotavirus is the primary cause of severe acute gastroenteritis among children under the age of five globally, leading to 128,500 to 215,000 vaccine-preventable deaths annually. There are six licensed oral, live-attenuated rotavirus vaccines: four vaccines pre-qualified for global use by WHO, and two country-specific vaccines. Expansion of rotavirus vaccines into national immunization programs worldwide has led to a 59% decrease in rotavirus hospitalizations and 36% decrease in diarrhea deaths due to rotavirus in vaccine-introducing countries.

AREAS COVERED

This review describes the current rotavirus vaccines in use, global coverage, vaccine efficacy from clinical trials, and vaccine effectiveness and impact from post-licensure evaluations. Vaccine safety, particularly as it relates to the risk of intussusception, is also summarized. Additionally, an overview of candidate vaccines in the pipeline is provided.

EXPERT OPINION

Considerable evidence over the past decade has demonstrated high effectiveness (80-90%) of rotavirus vaccines at preventing severe rotavirus disease in high-income countries, although the effectiveness has been lower (40-70%) in low-to-middle-income countries. Surveillance and research should continue to explore modifiable factors that influence vaccine effectiveness, strengthen data to better evaluate newer rotavirus vaccines, and aid in the development of future vaccines that can overcome the limitations of current vaccines.