Rotavirus vaccine strain transmission by vaccinated infants in the foster home

Literature review to identify evidence of secondary transmission of pentavalent human-bovine reassortant rotavirus vaccine (RV5) strains to unvaccinated subjects

BACKGROUND

Rotavirus is the leading cause of severe diarrhea in infants and young children. Live attenuated vaccines can lead to horizontal transmission with the risk of vaccine-derived disease in contacts. Transmission of pentavalent human-bovine reassortant rotavirus vaccine (RV5) strains leading to clinical disease was not well evaluated in the pivotal clinical trials, and only a few case reports have been described in the literature.

METHODS

We performed a systematic literature review to investigate secondary transmission of RV5 strains to unvaccinated subjects globally. We searched Embase, Medline for English papers, CNKI, Wan Fang for Chinese papers, and other resources (i.e., conference papers with full text) from January 2005 to June 2021. Eligibility criteria for inclusion were original articles based on non-interventional studies (case-control studies, cohort studies, cross-sectional studies) using RV5 strain transmission as outcomes. Other study or publication types were excluded, such as pre-clinical studies, interventional studies and case reports. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) was used, and study quality was assessed using the Newcastle-Ottawa Scale (NOS) for cohort studies and the JBI checklist for cross-sectional studies to assess the risk of bias.

RESULTS

The search generated 2,089 articles in total. Seven articles met all inclusion criteria, including six cohort studies and one cross-sectional study. All studies underwent quality assessment and complied with the quality criteria of the NOS or JBI checklist, respectively. Overall, none of the seven studies identified RV5 vaccine-type transmission to an unvaccinated population, in either hospitals or nurseries under a close contact environment. One study reported that 1% of unvaccinated infants had gastrointestinal symptoms, but all symptoms were attributed to other clinical conditions.

CONCLUSIONS

We found no evidence of horizontal transmission of RV5 strains to unvaccinated infants in a context of a limited amount and the descriptive nature of the identified studies.

Rotavirus genotypes and clinical outcome of natural infection based on vaccination status in the post-vaccine era

Rotavirus (RV) is a leading cause of gastroenteritis in children. In Japan, Rotarix (RV1; GlaxoSmithKline), which is a monovalent vaccine derived from human RV (G1P[8]), has been introduced since November 2011, and RotaTeq (RV5; MSD) which is an pentavalent, human-bovine mono-reassortant vaccine (G1, G2, G3, G4, and P1A[8]), has been introduced since July 2012. Long-term follow-up on vaccine efficacy and RV genotypical change should be carried out in order to control RV infection. The RV gastroenteritis (RVGE) outbreak occurred during the 2018/2019 season in Aichi prefecture, Japan. Therefore, the molecular epidemiology of RV among three different groups of RVGE, which were outpatients who received RV1, those who received RV5, and those without vaccination, was explored. Clinical features of RVGE patients were compared among the three patient groups. Children less than 15 years of age with gastroenteritis who visited any of seven pediatric practices between January and June 2019 were enrolled in the study. G, P, and E genotypes were determined by direct sequencing of reverse transcription-polymerase chain reaction products amplified from stool samples. Among 110 patients, there were 27, 28, and 55 in the RV1-vaccinated, RV5-vaccinated, and unvaccinated groups, respectively. The most frequent genotype was G8P[8] (92/110 patients, 83.6%). Genotype distributions did not significantly differ among the three patient groups (P = .125). Mean Vesikari score was significantly lower among RV1-vaccinated (7.1) and RV5-vaccinated patients (6.4) than among unvaccinated patients (10.2) (P < .001). Even in RVGE patients treated in an outpatient clinic, RV vaccine reduced the severity of the disease in this cohort.

Nosocomial infection with rotavirus vaccine strain in paediatric patients with immunodeficiency

In infants with immunodeficiency, rotavirus (RV) vaccines can be continuously excreted in stool. We analysed nosocomial infection with RV vaccine strain in immunodeficient paediatric patients. RV1 RNAs were detected in stool and serum samples from case A, who was vaccinated with RV1, and case B, who was not. PAGE analysis of serial stool samples of case A revealed several rearrangements of the RV genome. In case B, the only band pattern detected was the same as a rearrangement detected in case A at the same time. In summary, RV vaccination of infants with immunodeficiency poses a risk of nosocomial infections.

Vaccine-derived rotavirus strains in infants in England

OBJECTIVE

To describe infants with acute gastroenteritis symptoms in primary and secondary care who have the Rotarix vaccine-derived G1P[8] rotavirus strain identified in their stools.

DESIGN

This is a prospective national surveillance conducted by Public Health England (PHE). Rotavirus-positive samples from vaccine-eligible children are routinely submitted to PHE for confirmation, and general practitioners are requested to complete a surveillance questionnaire for all cases. The modified Vesikari Score was used to assess severity of gastroenteritis.

SETTING

England, July 2013-September 2016.

RESULTS

2637 rotavirus strains were genotyped and 215 (8%) identified as the Rotarix vaccine-derived G1P[8] strain. There were no Rotarix vaccine-derived G1P[8] strains detected in unimmunised infants. Rotarix vaccine-derived G1P[8] strains clustered around the time of rotavirus vaccination and were responsible for 82% (107 of 130) of rotavirus-positive samples in 2-month-old infants and 68% (36 of 53) in 3-month-old infants. However, 13 samples were obtained more than 7 weeks after the last vaccination date; 10 of these specimens were from six children who were subsequently diagnosed with severe combined immunodeficiency (SCID). Diarrhoea was the single most common presenting symptom (83.0%) in infants with Rotarix vaccine-derived G1P[8] strains, who were less likely to present with fever, vomiting, dehydration or severe gastroenteritis than infants with wild-type rotavirus infection.

CONCLUSIONS

Rotavirus identified in stools of infants around the time of their routine immunisations is most likely the Rotarix vaccine-derived G1P[8] strain. Infants with undiagnosed SCID at the time of rotavirus immunisation may experience prolonged gastroenteritis symptoms. Most infants with vaccine strains in their stools more than 7 weeks after immunisation had SCID.

Infrequent Transmission of Monovalent Human Rotavirus Vaccine Virus to Household Contacts of Vaccinated Infants in Malawi

Horizontal transmission of rotavirus vaccine virus may contribute to indirect effects of rotavirus vaccine, but data are lacking from low-income countries. Serial stool samples were obtained from Malawian infants who received 2 doses of monovalent human rotavirus vaccine (RV1) (days 4, 6, 8, and 10 after vaccination) and from their household contacts (8–10 days after vaccine). RV1 vaccine virus in stool was detected using semiquantitative real-time reverse-transcription polymerase chain reaction. RV1 fecal shedding was detected in 41 of 60 vaccinated infants (68%) and in 2 of 147 household contacts (1.4%). Horizontal transmission of vaccine virus within households is unlikely to make a major contribution to RV1 indirect effects in Malawi.

Rotavirus vaccination in the neonatal intensive care units: where are we? A rapid review of recent evidence

PURPOSE OF REVIEW

Rotavirus is a leading cause of viral acute gastroenteritis in infants. Neonates hospitalized in neonatal intensive care units (NICUs) are at risk of rotavirus infections with severe outcomes. The administration of rotavirus vaccines is only recommended, in the United States and Canada, upon discharge from the NICU despite rotavirus vaccines being proven well tolerated and effective in these populations, because of risks of live-attenuated vaccine administration in immunocompromised patients and theoretical risks of rotavirus vaccine strains shedding and transmission.We aimed to summarize recent evidence regarding rotavirus vaccine administration in the NICU setting and safety of rotavirus vaccines in preterm infants.

METHODS

We conducted a rapid review of the literature from the past 10 years, searching Medline and Embase, including all study types except reviews, reporting on rotavirus vaccines 1 and 5; NICU setting; shedding or transmission; safety in preterm. One reviewer performed data extraction and quality assessment.

RECENT FINDINGS

Thirty-one articles were analyzed. Vaccine-derived virus shedding following rotavirus vaccines existed for nearly all infants, mostly during the first week after dose 1, but with rare transmission only described in the household setting. No case of transmission in the NICU was reported. Adverse events were mild to moderate, occurring in 10-60% of vaccinated infants. Extreme premature infants or those with underlying gastrointestinal failure requiring surgery presented with more severe adverse events.

SUMMARY

Recommendations regarding rotavirus vaccine administration in the NICU should be reassessed in light of the relative safety and absence of transmission of rotavirus vaccine strains in the NICU.

Monitoring Shedding of Five Genotypes of RotaTeq Vaccine Viruses by Genotype-Specific Real-Time Reverse Transcription-PCR Assays

RotaTeq (RV5) is a widely used live attenuated pentavalent rotavirus (RV) vaccine. Although fecal shedding of RV vaccine strains persists for long time periods, it is unclear how each vaccine strain replicates in intestinal tissue and is excreted in stool. To examine this issue, we established RV5 genotype-specific real-time reverse transcription-PCR (RT-PCR) assays. Five real-time RT-PCR assays were designed for the VP7 gene in genotypes G1, G2, G3, G4, and G6. All assays exhibited excellent linearity, and the detection limit was 1 infectious unit (IU)/reaction for G2, G4, and G6 and 10 IUs/reaction for G1 and G3. No cross-reactivity was observed among G genotypes. The inter- and intra-assay coefficients of variation were less than 3%. The assays were used to examine 129 stool samples collected from eight infants who received RV5. In cases 1 and 2, who received three rounds of vaccination, RV shedding decreased gradually with the number of vaccinations. G1 and G6 shedding appeared to be predominant in comparison to shedding of the other genotypes. Patterns of fecal shedding of the five genotypes of vaccine viruses differed between the eight vaccine recipients. RV5 genotype-specific real-time RT-PCR assays will be useful to study the molecular biology of RV5 replication in infants and experimental animals.

Development of a new enzyme immunoassay for improved detection of rotavirus in fecal specimens of vaccinated infants

BACKGROUND

Group A rotavirus is the most common cause of acute diarrhea in young children worldwide. A simple and rapid enzyme immunoassay (EIA) has been commonly used to detect rotavirus infection and evaluate rotavirus vaccines. Currently licensed commercial EIA kits have low sensitivity. A more sensitive detection of rotavirus can improve rotavirus diagnostics and vaccine efficacy studies.

OBJECTIVE

A biotin-avidin based sandwich EIA was developed and compared with commercial EIA kits for improved detection of viral shedding in fecal samples from infants who received human rotavirus vaccine Rotarix in Mexico.

STUDY DESIGN

A monoclonal antibody (mAb: 1D4) specific to human rotavirus group antigen VP6 was prepared and used to develop a biotin-avidin based sandwich EIA. This EIA was employed to test 128 fecal samples from vaccinated infants, in comparison with two commercial EIA kits using RT-PCR as a reference.

RESULTS

A new biotin-avidin based sandwich EIA showed specific reaction to group A rotaviruses, but not to other enteric viruses. This new EIA had a detection rate of 36.7% for rotavirus antigen shedding in fecal specimens, which was two times higher (16.4%, 18.0%) than those from two commercial EIA kits.

CONCLUSION

The new EIA had specificity and higher sensitivity than commercial kits. This new EIA has the potential to detect rotavirus at lower concentration in clinical specimens and thus should be further evaluated as a more sensitive kit for use in diagnostics and vaccine efficacy and effectiveness studies.