Immunogenicity, duration of protection, effectiveness and safety of rubella containing vaccines: A systematic literature review and meta-analysis

Methodology of Epidemic Risk Analysis in the Naval Military

This review of the literature examines diseases and pathogen characteristics on military vessels, in order to improve the success of missions on a boat. Our aim is to understand the spread of disease, aiming to maximize biological resilience and hopefully eliminate outbreaks. Keyword research was conducted from various sources of information, including scientific publications, theses, public health organization websites, and clinical trials. A synthesis of bacterial, viral, fungal, and parasitosis characteristics was established, and a risk prioritization index was defined, based on contagiousness (basic reproduction number (R0)) and clinical severity. For instance, COVID-19 was assessed as moderately contagious, with critical severity, and Influenza A H1N1 as having a minor level of contagiousness with critical severity, resulting in a level two out of three risk prioritization index. This approach demonstrates that while diseases have numerous characteristics, a method for classifying them by isolating specific criteria and prioritizing them could be proposed. In conclusion, further work is needed to analyze onboard operator activities and develop simulation models related to pathogen characteristics.

Measles-Rubella Microarray Patches Phase III Clinical Trial Framework: Proposal and Considerations

Background: The Measles-Rubella Microarray Patch (MR-MAP) is an important technology that is expected to reduce coverage and equity gaps for measles-containing vaccines (MCVs), reach zero-dose children, and contribute to elimination of measles and rubella. MR-MAPs are anticipated to be easier to deploy programmatically and could be delivered by lesser-trained health workers, thereby increasing immunization coverage. The most advanced MR-MAP has reached clinical proof-of-concept through a Phase I/II trial in the target population of infants and young children. The World Health Organization (WHO) and partners have developed the Phase III clinical trial framework for MR-MAPs presented in this article. Objectives and Methods: The purpose of such framework is to inform the considerations, design and approach for the pivotal clinical trial design, while considering the anticipated data requirements to inform regulatory approval, WHO prequalification, and policy decision. Results: The proposed Phase III trial would compare the immunogenicity and safety of an MR-MAP with MR vaccine delivered subcutaneously in 9- to 10-month-old infants. An analysis of non-inferiority (NI) of immunogenicity would occur six weeks after the first dose. Should regulatory agencies or policy makers require, a proportion of infants could receive a second dose of either the same or alternate MR vaccine presentation six months after the first dose, with those children returning six weeks after the second dose for a descriptive assessment of immunogenicity, and then followed up six months after the second dose for evaluation of safety and immunogenicity. It is anticipated that this proposed pivotal Phase III trial framework would generate the required clinical data for regulatory licensure and WHO prequalification (PQ) of MR-MAPs. However, the trial design would need to be reviewed and confirmed by a national regulatory authority (NRA) that will assess the product for regulatory licensure and the WHO PQ team. Additional research will likely be required to generate data on concomitant vaccine delivery, the safety and immunogenicity of MR-MAPs in other age groups such as children 1-5 years and infants younger than 9 months of age, and the impact of MR-MAPs on coverage and equity. Such studies could be conducted during or after clinical MR-MAP development.

A measles and rubella vaccine microneedle patch in The Gambia: a phase 1/2, double-blind, double-dummy, randomised, active-controlled, age de-escalation trial

BACKGROUND

Microneedle patches (MNPs) have been ranked as the highest global priority innovation for overcoming immunisation barriers in low-income and middle-income countries. This trial aimed to provide the first data on the tolerability, safety, and immunogenicity of a measles and rubella vaccine (MRV)-MNP in children.

METHODS

This single-centre, phase 1/2, double-blind, double-dummy, randomised, active-controlled, age de-escalation trial was conducted in The Gambia. To be eligible, all participants had to be healthy according to prespecified criteria, aged 18-40 years for the adult cohort, 15-18 months for toddlers, or 9-10 months for infants, and to be available for visits throughout the follow-up period. The three age cohorts were randomly assigned in a 2:1 ratio (adults) or 1:1 ratio (toddlers and infants) to receive either an MRV-MNP (Micron Biomedical, Atlanta, GA, USA) and a placebo (0·9% sodium chloride) subcutaneous injection, or a placebo-MNP and an MRV subcutaneous injection (MRV-SC; Serum Institute of India, Pune, India). Unmasked staff ransomly assigned the participants using an online application, and they prepared visually identical preparations of the MRV-MNP or placebo-MNP and MRV-SC or placebo-SC, but were not involved in collecting endpoint data. Staff administering the study interventions, participants, parents, and study staff assessing trial endpoints were masked to treatment allocation. The safety population consists of all vaccinated participants, and analysis was conducted according to route of MRV administration, irrespective of subsequent protocol deviations. The immunogenicity population consisted of all vaccinated participants who had a baseline and day 42 visit result available, and who had no protocol deviations considered to substantially affect the immunogenicity endpoints. Solicited local and systemic adverse events were collected for 14 days following vaccination. Unsolicited adverse events were collected to day 180. Age de-escalation between cohorts was based on the review of the safety data to day 14 by an independent data monitoring committee. Serum neutralising antibodies to measles and rubella were measured at baseline, day 42, and day 180. Analysis was descriptive and included safety events, seroprotection and seroconversion rates, and geometric mean antibody concentrations. The trial was registered with the Pan African Clinical Trials Registry PACTR202008836432905, and is complete.

FINDINGS

Recruitment took place between May 18, 2021, and May 27, 2022. 45 adults, 120 toddlers, and 120 infants were randomly allocated and vaccinated. There were no safety concerns in the first 14 days following vaccination in either adults or toddlers, and age de-escalation proceeded accordingly. In infants, 93% (52/56; 95% CI 83·0-97·2) seroconverted to measles and 100% (58/58; 93·8-100) seroconverted to rubella following MRV-MNP administration, while 90% (52/58; 79·2-95·2) and 100% (59/59; 93·9-100) seroconverted to measles and rubella respectively, following MRV-SC. Induration at the MRV-MNP application site was the most frequent local reaction occurring in 46 (77%) of 60 toddlers and 39 (65%) of 60 infants. Related unsolicited adverse events, most commonly discolouration at the application site, were reported in 35 (58%) of 60 toddlers and 57 (95%) of 60 infants that had received the MRV-MNP. All local reactions were mild. There were no related severe or serious adverse events.

INTERPRETATION

The safety and immunogenicity data support the accelerated development of the MRV-MNP.

FUNDING

Bill & Melinda Gates Foundation.

The path to eradication of rubella

Since 1969, rubella and its harmful effect on fetuses infected in utero can be prevented by rubella vaccine, usually given in combination with measles vaccine. The rubella vaccine is highly protective both in children and in adults including women intending to become pregnant. Owing to the use of combined measles and rubella vaccines, congenital rubella infection has been eliminated from the Western Hemisphere and nearly all of Europe. Such combined vaccination is now being applied throughout the world, posing the possibility of eventual rubella eradication. The existence of viruses of animals related to rubella does not appear to be a barrier to eradication of the human virus. However, persistent rubella virus in infants infected in utero and of immunosuppressed patients with granulomas may pose a problem for eradication. Nevertheless, this review posits that eradication of rubella is now feasible if routine vaccination of infants and surveillance for chronic infection are correctly applied.

Quantification of Waning Immunity After Measles Vaccination-Evidence From a Seroprevalence Study

We aimed to quantify rates of waning immunity after measles vaccination from seroprevalence data collected in a study of a population with high vaccination coverage and a fixed vaccination schedule. Data were collected during a national survey (the Immunological Survey) carried out in the Slovak Republic in 2018. The average rate of waning immunity against measles after the first dose of measles, mumps, and rubella (MMR) vaccine (ages 1.5-10 years) was 9.7% per year from the geometric mean titer value of 2,634 mUI/mL. The average waning rate after the second dose of MMR vaccine (ages 10-33 years) was significantly lower: 4.8% per year from the lower geometric mean titer of 1,331 mUI/mL. This decline in antibody levels suggests that vaccine-induced protection may be compromised and results in an increase in the proportion of seronegative/borderline individuals. These outcomes may provide a valuable source for critical assessment of direct and indirect effects of MMR vaccination.

Do adolescents need a rubella vaccination campaign? Rubella serosurvey among healthy children in Hangzhou, China

The aim of this study was to evaluate the seroprevalence of rubella antibodies and factors associated with antibody seropositivity after vaccination among healthy children aged 14 and below. A multi-stage stratified random sampling method was employed to recruit participants for the rubella serological test. An enzyme-linked immunosorbent assay method was used to detect human IgG antibodies with avidity for rubella virus in the sera of participants. Univariate and multivariate analyses were used to analyze associations between variables. A total of 778 subjects were included in the subsequent analysis. The overall positive rate of rubella antibody was 83.0% (95%CI: 80.2-85.5%), and the overall geometric mean concentration (GMC) was 58.05 IU/ml. In multivariate analysis, gender, residence, birth year group, and time since the last rubella-containing vaccines (RCV) vaccination were significantly associated with the seroprevalence of rubella antibodies. Our study showed a decreasing trend in rubella antibody positivity and GMC in the population aged five to 14 years. Therefore, we recommend a catch-up dose of RCV for adolescents and young people aged over 14 years not yet vaccinated.

Safety of varicella vaccination strategies: An overview of reviews

The safety of new vaccines under development as well as existing vaccines is a key priority for national and international public health agencies. A number of countries have implemented universal childhood varicella vaccination programmes over the past 30 years. However, strategies differ in terms of the number of doses, type of vaccine(s) recommended, age at vaccination and interval between doses for a two-dose schedule. An overview of reviews was undertaken to assess the existing systematic review evidence of the safety of varicella vaccination strategies. The review was restricted to immunocompetent children aged 9 months to 6 years inclusive. A comprehensive search of databases, registries and grey literature was conducted up to 2 February 2022. Two reviewers independently screened, extracted data and assessed the methodological quality of included reviews. Overlap of included reviews was also assessed. A total of 17 reviews, incorporating both the monovalent varicella only and quadrivalent measles-mumps-rubella-varicella (MMRV) vaccines were included in the overview; six assessed the safety of one-dose strategies, four assessed the safety of two-dose strategies and 14 reviews did not specify the dosing strategy. The evidence suggests that mild local and systemic reactions are relatively common with varicella vaccination. Febrile seizures are also possible adverse effects of both the monovalent and quadrivalent MMRV vaccine, but serious adverse reactions are rare. While most reviews contained methodological flaws, and analysis by vaccine type and dosing strategy was restricted due to lack of detail in reporting of the reviews, there was clear and consistent evidence from a substantial evidence base, comprising 34 randomised controlled trials and 62 other primary studies/reviews, that varicella vaccination is safe.

Past as Prologue-Use of Rubella Vaccination Program Lessons to Inform COVID-19 Vaccination

The rapid rollout of vaccines against COVID-19 as a key mitigation strategy to end the global pandemic might be informed by lessons learned from rubella vaccine implementation in response to the global rubella epidemic of 1963-1965. That rubella epidemic led to the development of a rubella vaccine that has been introduced in all but 21 countries worldwide and has led to elimination of rubella in 93 countries. Although widespread introduction and use of rubella vaccines was slower than that for COVID-19 vaccines, the process can provide valuable insights for the continued battle against COVID-19. Experiences from the rubella disease control program highlight the critical and evolving elements of a vaccination program, including clearly delineated goals and strategies, regular data-driven revisions to the program based on disease and vaccine safety surveillance, and evaluations to identify the vaccine most capable of achieving disease control targets.

Rubella

Rubella is an acute illness caused by rubella virus and characterised by fever and rash. Although rubella is a clinically mild illness, primary rubella virus infection in early pregnancy can result in congenital rubella syndrome, which has serious medical and public health consequences. WHO estimates that approximately 100 000 congenital rubella syndrome cases occur per year. Rubella virus is transmitted through respiratory droplets and direct contact. 25-50% of people infected with rubella virus are asymptomatic. Clinical disease often results in mild, self-limited illness characterised by fever, a generalised erythematous maculopapular rash, and lymphadenopathy. Complications include arthralgia, arthritis, thrombocytopenic purpura, and encephalitis. Common presenting signs and symptoms of congenital rubella syndrome include cataracts, sensorineural hearing impairment, congenital heart disease, jaundice, purpura, hepatosplenomegaly, and microcephaly. Rubella and congenital rubella syndrome can be prevented by rubella-containing vaccines, which are commonly administered in combination with measles vaccine. Although global rubella vaccine coverage reached only 70% in 2020 global rubella eradiation remains an ambitious but achievable goal.

Early Life Inflammation and the Developing Hematopoietic and Immune Systems: The Cochlea as a Sensitive Indicator of Disruption

Emerging evidence indicates that perinatal infection and inflammation can influence the developing immune system and may ultimately affect long-term health and disease outcomes in offspring by perturbing tissue and immune homeostasis. We posit that perinatal inflammation influences immune outcomes in offspring by perturbing (1) the development and function of fetal-derived immune cells that regulate tissue development and homeostasis, and (2) the establishment and function of developing hematopoietic stem cells (HSCs) that continually generate immune cells across the lifespan. To disentangle the complexities of these interlinked systems, we propose the cochlea as an ideal model tissue to investigate how perinatal infection affects immune, tissue, and stem cell development. The cochlea contains complex tissue architecture and a rich immune milieu that is established during early life. A wide range of congenital infections cause cochlea dysfunction and sensorineural hearing loss (SNHL), likely attributable to early life inflammation. Furthermore, we show that both immune cells and bone marrow hematopoietic progenitors can be simultaneously analyzed within neonatal cochlear samples. Future work investigating the pathogenesis of SNHL in the context of congenital infection will therefore provide critical information on how perinatal inflammation drives disease susceptibility in offspring.

High seroprevalence of rubella in Thai children with a 2-dose MMR national immunization policy

Rubella is generally a mild disease, but infection during pregnancy can cause congenital rubella syndrome. Thailand has implemented a two-dose MMR vaccination policy since 2010. This study aimed to describe the seroprevalence rate of rubella among children and adolescents in Thailand. We conducted a cross-sectional study of 132 healthy children (aged 3-9 years) who had received 2 doses of rubella vaccine and 424 adolescents (aged 10-18 years) who were expected to receive at least 1 dose of rubella vaccine. Stored serum samples from healthy children and recently drawn serum samples from adolescents were tested for rubella IgG antibody using a commercial enzyme-linked immunosorbent assay (ELISA) kit (EUROIMMUN). Seroprotection was defined as a rubella IgG level ≥ 10 IU/mL. The rubella seroprevalence rate among children and adolescents who had 2 documented doses of MMR was 97.0% (95 %CI 92.5-99.2%) and 85.4% (95% CI 78.8-90.6%, p < 0.01) respectively. The geometric mean titer of rubella was higher in children, 38.3 (95% CI 33.5-43.9) compared to adolescents, 22.5 (19.4-25.9) IU/mL. We observed an inverse correlation between the rubella titer and time interval from the second rubella containing vaccine dose (R = -0.30, p < 0.01). A 2-dose MMR vaccination course produces a high seroprevalence of rubella immunity in children, which decreases with time, suggesting waning of immunity. Thai clinical trials registry number TCTR20191120001.