Summary of the special symposium 'Towards Elimination of Rubella'

A special symposium titled 'Towards Elimination of Rubella' was held at the 23rd Annual Meeting of the Japanese Society for Vaccinology in Tokyo, Japan on November 30, 2019. Representatives from the Japanese national government, a local government, and a private company presented their efforts to control rubella, and the group discussed the challenges of eliminating rubella in Japan.

Comparative studies of rubella virus immunity of immunized and non-immunized pregnant women visiting Kogi State University Teaching Hospital, Anyigba, North Central Nigeria

Rubella is endemic worldwide and poses a serious threat to infants and pregnant women. Although the disease has been widely reported in parts of the country, there is currently no documented evidence of the disease in Anyigba. A comparative study of rubella immunity was conducted among immunized and non-immunized pregnant women visiting the Kogi State University Teaching Hospital, Anyigba. In a cross-sectional study, blood samples collected from 300 pregnant women (immunized = 127; non-immunized = 173) were tested for rubella antibodies using ELISA kit. Overall, anti-rubella-IgM and IgG seroprevalence rates of 38 (12.7%) and 83 (27.7%) were detected. Seventy (55.1%) of the immunized against 13 (7.5%) of non-immunized women had detectable IgG. The non-immunized women were significantly more seropositive for IgM than the immunized who recorded higher prevalence of IgG. Immunized and non-immunized women aged 23-32 years had higher IgG and IgM positivity rates. The difference in IgM and IgG seropositivity rates in relation to vaccination was statistically significant (P < 0.05) between the immunized (0.8%, 55.1%) and vaccine-naïve subjects (21.4%, 7.5%). Low level of awareness and high susceptibility to rubella virus infection especially among the non-immunized women was confirmed in study area, thus the need for government to strengthen education of masses and to make rubella vaccination freely available for women of childbearing age.

The status of rubella IgG antibody titer between antenatal and postnatal among pregnant non-immune to rubella

Background: The infection of rubella in pregnancy is worrisome due to the fact that it causes miscarriages, congenital defects, and Congenital Rubella Syndrome (CRS). The purpose of this study was to determine the status of Rubella IgG antibody levels both during the antenatal and postnatal periods among pregnant women nonimmune to rubella and the incidence of exposure to rubella in pregnancy. Methods: This was a prospective cohort study that included 4770 pregnant, who attended the obstetric clinics and delivered in Women's Specialized Hospital, King Fahad Medical City, between January and December 2015. The study utilized the following measures for rubella screening tests (IgG and IgM) during the antenatal and postnatal period. Pregnant women with recent rubella infection (IgM antibody positive), history of rubella infection, or had immunity against rubella (IgG antibody concentration ≥10 IU/ml) were excluded from the study. Results: The prevalence of pregnant women nonimmune to rubella was 6.3% (n = 301). The majority (93.7%) were immune (IgG antibody concentration ≥10 IU/ml). No patients tested positive for rubella (IgM +ve). Overall, The Median (IQR) Rubella (IgG) in the antenatal period (6.3 (8.30-5.00) IU/m) was significantly less in comparison to the postnatal period (5.0 (6.40-5.00) IU/m). The difference was statistically significant, p <.001. Conclusion: There is a significant decrease in the Rubella (IgG) titer between antenatal and postpartum periods, and we report a very low incidence of rubella infection and CRS among pregnant women nonimmune to rubella.

Vaccine-associated Rubella - a report of two cases and a review of the literature

We report the clinical characteristics of two adult patients, presenting with a typical erythematous rash consistent with rubella disease after MMR vaccination. Both patients had an uncomplicated clinical course and recovered uneventfully. One patient was confirmed to have vaccine-associated rubella via sequencing of virus isolated in viral culture. The other patient had a pharyngeal swab positive for rubella virus PCR, with sequencing matching the vaccine strain. There are few reports of clinical disease from rubella vaccine-strains in the literature. Previous authors have reported severe disseminated vaccine-associated rubella in both immunodeficient and immunocompetent patients. Further study is required to ascertain the incidence, risk factors, and clinical characteristics of this condition; as well as investigate the extent of horizontal transmission to guide infection control recommendations.

Diagnostic algorithm for the confirmation of cases of measles and rubella in Mexico

Due to the successful implementation of measles and rubella elimination strategies, Mexico announced the interruption of endemic transmission of measles in 1996 and that of rubella in 2008. After a verification process, the region of the Americas was declared free of rubella and congenital rubella syndrome in 2015 and of measles in 2016. In order to maintain the elimination status in Mexico, it is essential to continue laboratory surveillance within the framework of the Global Measles and Rubella Laboratory Network. The Institute of Epidemiological Diagnosis and Reference, through the National Network of Public Health Laboratories, guarantees timely and reliable results in view of the possible reintroduction of these and other emerging pathogens.

Perception of rubella risk in pregnancy: an epidemiological survey on a sample of pregnant women

BACKGROUND

Rubella is a common exanthematous viral disease all over the world. The disease can be prevented by administering a safe and effective vaccine, and in Italy it is subject to reporting obligations. A national plan for the elimination of measles and congenital rubella (in Italian "PNEMoRC") was approved in 2003 and updated in 2010. This plan originally aimed at reducing the susceptible target population (women in fertile age, 15-49 years old) to below 5% and at eliminating the congenital form of rubella by 2015, a goal which has not been achieved yet.

STUDY DESIGN

Our research work was focused on a convenience sample of pregnant women attending the antenatal classes at the two main hospitals in Messina, Sicily (Italy).

METHODS

After we obtained an informed consent, we administered to 200 Italian and foreign pregnant women an anonymous questionnaire reporting socio-demographic characteristics, type of gynaecological assistance and information received about Rubella serological statu.

RESULTS

The mean age was 30.6 years ± 5.45. The majority of these women were married, at work and with a high educational level. Most of them (75.3%) reported to be assisted by a private gynaecologist, while only 24.7% used a public facility. A remarkable percentage (62.8%) of these women reported to be serologically negative at the anti-rubella antibodies test, but, only 7.5% of them reported to have passed the anti-rubella antibody test before the conception.

CONCLUSION

Our results clearly show that we are still far from achieving the elimination of rubella risk in pregnancy. We are facing a cultural gap perhaps also due to a generalized loss of "historical memory" about the impact that infectious diseases have had in the past in terms of mortality and morbidity. In fact, alongside the considerable drop in vaccination coverage in the recent years, our research also reveals a reduced focus on pre-conceptional testing and limited awareness of associated risks. Furthermore, we correlated the serological status with the sociodemographic characteristics of these women and found a statistically significant correlation with their age and their educational level (P<0.05). A lot still needs to be done to improve the situation; in particular, better education at various levels could considerably increase the awareness among women about this relevant public health issue.

Seroprevalences of antibodies against pertussis, diphtheria, tetanus, measles, mumps and rubella: A cross-sectional study in children following vaccination procedure in Guangzhou, China

This study investigated the concentrations and seroprevalence of immunoglobulin G (IgG) antibodies against pertussis, diphtheria, tetanus, measles, mumps and rubella among children in Guangzhou, China. We conducted a cross-sectional study focusing on the post-vaccination immune statuses of children on scheduled immunisation. Human IgG antibody against six diseases were measured using commercial enzyme-linked immunosorbent assay kits. Of 620 subjects, the male-to-female ratio was 2.04 (416/204). Seroprevalence (81.97% vs 90.20%) and IgG concentrations (686.55 IU/mL vs 884.26 IU/mL, P < 0.05) for measles, tetanus (0.94 IU/mL vs 1.21 IU/mL) and rubella (34.33 IU/mL vs 47.37 IU/mL) were all higher in females. No differences based on sex were observed in the seroprevalence and IgG concentrations for anti-pertussis antibodies, anti-diphtheria antibodies and anti-mumps. Slight increase in seroprevalence and IgG concentration occurred with anti-pertussis antibodies after primary and booster vaccinations (from 0.00% [1 m], 5.45% [6 m], to 17.14% [1.5 yr]; and from 8.57% [5 yr] to 15.79% [6 yr]). Although no booster vaccination was given after age 6 yr, the seroprevalence and IgG concentration for anti-pertussis antibodies remained relatively stable. For diphtheria, tetanus, measles and rubella, seroprevalence reached their peaks after the primary and first booster vaccination. A plateau occurred after age 1.5 yr with a declining trend in subjects >8-10 yr. The IgG concentrations of these 4 pathogens showed a dramatic increase after primary vaccination, with steadily declining trends thereafter. For mumps, subjects showed increased seroprevalence and IgG concentration after the primary mumps-containing vaccination in 1.5-yr-olds (from 7.14% to 57.14%; 52.13 IU/mL to 214.18 IU/mL); however, following that low seroprevalence levels (from 42.86% to 80.00%) were observed. The post-vaccination immune statuses against diphtheria, tetanus, measles and rubella were relatively satisfactory, compared to those against pertussis and mumps. Booster vaccination against pertussis and mumps at appropriate time should be considered.

Measles and rubella IgG seroprevalence in persons 6 month-35 years of age, Mongolia, 2016

BACKGROUND

In 2015-2016, Mongolia experienced an unexpected large measles outbreak affecting mostly young children and adults. After two nationwide vaccination campaigns, measles transmission declined. To determine if there were any remaining immunity gaps to measles or rubella in the population, a nationally representative serosurvey for measles and rubella antibodies was conducted after the outbreak was over.

METHODS

A nationwide, cross-sectional, stratified, three-stage cluster serosurvey was conducted in November-December 2016. A priori, four regional strata (Ulaanbaatar, Western, Central, and Gobi-Eastern) and five age strata (6 months-23 months, 2-7 years, 8-17 years, 18-30 years, and 31-35 years) were created. Households were visited, members interviewed, and blood specimens were collected from age-appropriate members. Blood specimens were tested for measles immunoglobulin G (IgG) and rubella IgG (Enzygnost® Anti-measles Virus/IgG and Anti-rubella Virus/IgG, Siemens, Healthcare Diagnostics Products, GmbH Marburg, Germany). Factors associated with seropositivity were evaluated.

RESULTS

Among 4598 persons aged 6 months to 35 years participating in the serosurvey, 94% were measles IgG positive and 95% were rubella IgG positive. Measles IgG seropositivity was associated with increasing age and higher education. Rubella IgG seropositivity was associated with increasing age, higher education, smaller household size, receipt of MMR in routine immunization, residence outside the Western Region, non-Muslim religious affiliation, and non-Kazakh ethnicity. Muslim Kazakhs living in Western Region had the lowest rubella seroprevalence of all survey participants.

CONCLUSIONS

Nationally, high immunity to both measles and rubella has been achieved among persons 1-35 years of age, which should be sufficient to eliminate both measles and rubella if future birth cohorts have ≥ 95% two dose vaccination coverage. Catch-up vaccination is needed to close immunity gaps found among some subpopulations, particularly Muslim Kazakhs living in Western Region.

Rubella in Poland in 2017

INTRODUCTION

Rubella is the disease subject to the elimination programme coordinated by the World Health Organization (WHO). Generally, rubella is an infection of mild course among children but in the case of pregnant women, who are not immunized, the probability of the occurrence of severe congenital abnormalities (congenital rubella syndrome) may amount to 95%. The strategy of the countries belonging to the WHO European Region is directed to the interruption of the rubella virus transmission in the environment in order to prevent the cases of congenital rubella syndrome (CRS).

OBJECTIVES

The aims of the present article are to analyze the epidemiological situation of rubella in Poland in 2017 and to discuss the rubella vaccination coverage.

MATERIAL AND METHODS

The epidemiological situation of rubella in Poland was analyzed on the basis of publications: “Infectious diseases and poisonings in Poland in 2017” and “Vaccinations in Poland in 2017”.

RESULTS

In 2017, there was a decrease in the number of rubella cases - with registered 476 cases (in 2016 – 1 105 cases) - and a decline in incidence (from 2.9 per 100 000 to 1.2). The highest incidence rate, regardless of gender and the environment, was observed among children aged 0-4 years (11.8 per 100,000). In 2017, no cases of congenital rubella syndrome were registered.

SUMMARY AND CONCLUSIONS

In 2017, there was a decrease in the number of rubella cases. In Poland Rubella is reported exclusively on the basis of the clinical picture. The proportion of laboratory tests confirming/excluding rubella infection is still very low in Poland.

Strategies for elimination of rubella in pregnancy and of congenital rubella syndrome in high and upper-middle income countries

Rubella infection generally leads to mild symptoms; otherwise, in pregnant women it can cause severe damages. The only way to prevent rubella is vaccine. Before the introduction of the vaccine, up to 4 babies in 1000 live births were born with CRS.

This work aims to review the most important strategies for the elimination of CRS in upper and high-income countries.

Papers were selected through a PubMed search up to January 2019, using keywords rubella, congenital rubella syndrome and epidemiology. Articles published in the last 12 years and referred to upper income and high-income countries in title or abstract were included.

Sixty-five papers were selected dealing with one or more of the following strategies: increasing of rubella vaccination coverage in childbearing age women, males, immigrants; exploitation of all appropriate occasions; improving of rubella surveillance.

Despite numerous suggestions and indications for valid strategies to eliminate rubella in pregnancy and congenital rubella syndrome, a practical application is often missing.

Congenital infections in Hong Kong: an overview of TORCH

Congenital infections refer to a group of perinatal infections that may have similar clinical presentations, including rash and ocular findings. TORCH is the acronym that covers these infections (toxoplasmosis, other [syphilis], rubella, cytomegalovirus, herpes simplex virus). There are, however, other important causes of intrauterine/perinatal infections, including enteroviruses, varicella zoster virus, Zika virus, and parvovirus B19. Intrauterine and perinatal infections are significant causes of fetal and neonatal mortality and important contributors to childhood morbidity. A high index of suspicion for congenital infections and awareness of the prominent features of the most common congenital infections can help to facilitate early diagnosis, tailor appropriate diagnostic evaluation, and if appropriate, initiate early treatments. In the absence of maternal laboratory results diagnostic of intrauterine infections, congenital infections should be suspected in newborns with certain clinical features or combinations of clinical features, including hydrops fetalis, microcephaly, seizures, cataract, hearing loss, congenital heart disease, hepatosplenomegaly, jaundice, or rash. Primary prevention of maternal infections during pregnancy is the cornerstone of prevention of congenital infection. Available resources should focus on the promotion of public health.

Immunogenicity and safety of the RTS,S/AS01 malaria vaccine co-administered with measles, rubella and yellow fever vaccines in Ghanaian children: A phase IIIb, multi-center, non-inferiority, randomized, open, controlled trial

BACKGROUND

To optimize vaccine implementation visits for young children, it could be efficient to administer the first RTS,S/AS01 malaria vaccine dose during the Expanded Programme on Immunization (EPI) visit at 6 months of age together with Vitamin A supplementation and the third RTS,S/AS01 dose on the same day as yellow fever (YF), measles and rubella vaccines at 9 months of age. We evaluated the safety and immunogenicity of RTS,S/AS01 when co-administered with YF and combined measles-rubella (MR) vaccines.

METHODS

In this phase 3b, open-label, controlled study (NCT02699099), 709 Ghanaian children were randomized (1:1:1) to receive RTS,S/AS01 at 6, 7.5 and 9 months of age, and YF and MR vaccines at 9 or 10.5 months of age (RTS,S coad and RTS,S alone groups, respectively). The third group received YF and MR vaccines at 9 months of age and will receive RTS,S/AS01 at 10.5, 11.5 and 12.5 months of age (Control group). All children received Vitamin A at 6 months of age. Non-inferiority of immune responses to the vaccine antigens was evaluated 1 month following co-administration versus RTS,S/AS01 or EPI vaccines (YF and MR vaccines) alone using pre-defined non-inferiority criteria. Safety was assessed until Study month 4.5.

RESULTS

Non-inferiority of antibody responses to the anti-circumsporozoite and anti-hepatitis B virus surface antigens when RTS,S/AS01 was co-administered with YF and MR vaccines versus RTS,S/AS01 alone was demonstrated. Non-inferiority of antibody responses to the measles, rubella, and YF antigens when RTS,S/AS01 was co-administered with YF and MR vaccines versus YF and MR vaccines alone was demonstrated. The safety profile of all vaccines was clinically acceptable in all groups.

CONCLUSIONS

RTS,S/AS01 can be co-administered with Vitamin A at 6 months and with YF and MR vaccines at 9 months of age during EPI visits, without immune response impairment to any vaccine antigen or negative safety effect.

Rubella IgM epidemiology in the pre-rubella vaccination era in Uganda

Background

Control of Rubella and Congenital Rubella Syndrome using vaccination has shown great success in the America’s. Uganda is due to introduce the Rubella vaccine however the magnitude of transmission is not well documented. Therefore this study was done to determine IgM sero-prevalance for Rubella in order to help monitor vaccine effectiveness post introduction of the vaccine in routine vaccination programme.

Methods

A retrospective review of suspected measles cases data for the reporting period January 2007 to December 2016 in Uganda was Done. rubella IgM testing was done on 15,296 of the cases and the data was analyzed using STATA version 13.

Results

In total 15,296 cases were tested and 4255 (27.8%) tested positive and among females aged 15-49 years 88 out of 322 (27%) tested positive. The age distribution range was 0–80 years, rubella IgM positivity was reported in all the 15 regions of Uganda and throughout the ten year period in every month. Age group 5–15 years had OR 2.5 p-value < 0.001 of being rubella IgM positive compared to age < 5 years and testing measles IgM negative OR 6.3 p-value < 0.001.

Conclusion

Rubella is endemic in Uganda and although rubella IgM positivity is highest in the age 5-15 years even the younger, older and women of reprodutive age are affected. This means the risk of Congenital Rubella Syndrome is high hence the need to introduce the rubella vaccine for infants and pregnant mothers and continued surveillance to enhance its control.

Rubella seroepidemiology among Korean women: Two decades after a combined vaccination strategy

OBJECTIVES

The aim was to examine rubella seronegativity among women of childbearing age after the introduction of rubella-containing vaccine (RCV) among teenage girls and universal MMR programs in South Korea.

METHODS

The serum IgG data of 72 114 women aged 20-49 years, who had undergone rubella antibody testing at the Gangnam CHA Medical Center between 2004 and 2018, were examined. A serum IgG level <10.0 IU/ml was considered negative. The study population was divided into three cohorts based on the vaccination policy: cohort 1, 1955-1976 (no national immunization program); cohort 2, 1977-1985 (national rubella only vaccination for high schoolers); cohort 3, 1986-1993 (combination strategy). We compared the rate of seronegativity and the adjusted odds ratio (OR) of seronegativity of each cohort.

RESULTS

The overall proportion of seronegative women decreased significantly, from 6.1% in 2004 to 2.5% in 2018 (Kendall tau = -0.89, p < 0.001). The rate of seronegativity was highest among women who were not targeted for national immunization (born in 1955-1977, 5.2%), while it was lowest among candidates receiving routine and catch-up vaccinations (born in 1986-1993, 2.2%). When controlling for the effect of age and year of testing, the OR for seronegativity was lower for cohort 2 (adjusted OR 0.68, 95% confidence interval (CI) 0.60-0.76) and cohort 3 (OR 0.55, 95% CI 0.40-0.75) when compared to cohort 1.

CONCLUSIONS

Women who were covered by either vaccination program were less susceptible to rubella infection, supporting the value of both approaches. The study findings will serve as empirical evidence for an immunization program targeted towards young women and children.

Epidemiology of acute rubella infection in Zambia during the pre-vaccination period (2005-2016) as a baseline for monitoring rubella epidemiology in the post-rubella vaccine introduction era

BACKGROUND

Rubella is highly under reported in Zambia as in most sub-Saharan countries despite being a disease of major public health concern especially among women of childbearing age. In September 2016, Zambia introduced a combined measles-rubella vaccine in children 0-14 years. In this study, we estimated the proportion positive for acute rubella among suspected but negative measles cases between 2005 and 2016 and determined its correlates for monitoring rubella epidemiology post-rubella vaccine introduction.

METHODS

In a retrospective study, 4497 measles IgM negative serum samples from 5686 clinically suspected measles cases were examined for rubella IgM antibodies using the Siemens, Enzygnost® ELISA kit at the national measles laboratory. Data on demographics, year and month of onset were extracted from the surveillance data. Multivariate logistic regression analysis using backward variable selection was conducted to determine independent predictors for acute rubella. The magnitude of association was estimated using adjusted odds ratio with a 95% confidence interval.

RESULTS

Overall, a proportion of 29.2% (1313/4497) affecting mostly those between 5 and 24 years was determined. Only age, province, month and year were independently associated with acute rubella. The regional proportions varied from 21.8-37.3% peaking in the month of October. Persons in the age group 10-14 years (Adjusted Odds Ratio [AOR] = 2.43; 95% CI [2.01-2.95]) were more likely while those aged < 1 year less likely (AOR = 0.31; 95% CI [021-0.48]) to have acute rubella compared to those aged 25 years or older. Persons in 2010 were less likely (AOR = 0.12; CI [0.05, 0.28]) to have acute rubella compared to those in 2016. While acute rubella was more likely to occur between July and November compared to December, it was less likely to occur between February and May.

CONCLUSIONS

Rubella virus was circulating in Zambia between 2005 and 2016 affecting mostly persons in the age group 5-24 years peaking in the hot dry season month of October. Although vaccination against rubella has been launched, these baseline data are important to provide a reference point when determining the impact of the vaccination program implemented.

Using models to shape measles control and elimination strategies in low- and middle-income countries: A review of recent applications

After many decades of vaccination, measles epidemiology varies greatly between and within countries. National immunization programs are therefore encouraged to conduct regular situation analyses and to leverage models to adapt interventions to local needs. Here, we review applications of models to develop locally tailored interventions to support control and elimination efforts. In general, statistical and semi-mechanistic transmission models can be used to synthesize information from vaccination coverage, measles incidence, demographic, and/or serological data, offering a means to estimate the spatial and age-specific distribution of measles susceptibility. These estimates complete the picture provided by vaccination coverage alone, by accounting for natural immunity. Dynamic transmission models can then be used to evaluate the relative impact of candidate interventions for measles control and elimination and the expected future epidemiology. In most countries, models predict substantial numbers of susceptible individuals outside the age range of routine vaccination, which affects outbreak risk and necessitates additional intervention to achieve elimination. More effective use of models to inform both vaccination program planning and evaluation requires the development of training to enhance broader understanding of models and where feasible, building capacity for modelling in-country, pipelines for rapid evaluation of model predictions using surveillance data, and clear protocols for incorporating model results into decision-making.

Maternal infections

Congenital infections are infections transmitted from mother to child during pregnancy (transplacentally) or delivery (peripartum). They have the potential to adversely affect fetal development and long-term neurodevelopmental outcome through inflammatory, destructive, developmental, or teratogenic lesions of the brain. Because the fetal/neonatal brain has a limited capacity to respond to injury, early inflammatory changes may be difficult to visualize and only manifest as neurocognitive disability later in life. Teratogenic effects, which may include aberrations of neuronal proliferation and migration, are more easily visible on imaging, but may be equally difficult to use to predict long-term neurocognitive outcomes. This chapter reviews the general pathophysiology of congenital infection and describes the epidemiology, the antenatal and postnatal diagnosis, and the treatment of congenital infections as well as the long-term neurodevelopmental outcomes.

Rubella seroprevalence in pregnant women living with and without HIV in Soweto, South Africa

OBJECTIVES

Rubella infection during pregnancy may cause foetal death or congenital rubella syndrome. In South Africa, the national public immunization programme does not include rubella vaccination. The aim of this study was to evaluate rubella sero-epidemiology in pregnant South African women living with and without HIV.

METHODS

Serum samples obtained from women living with HIV (n=552) and without HIV (n=552) were tested for rubella immunoglobulin G antibodies using an ELISA. The proportions of women with seronegative titres (<8IU/ml) and seropositive titres (≥11IU/ml), and geometric mean titres (GMT) were compared by age group and HIV status.

RESULTS

The overall proportion of rubella seropositivity was 97.8%. The proportion of seropositive women increased with age group (18-25 years: 97.0%; 26-32 years: 97.7%; 33-40 years: 99.3%; p=0.047 after adjusting for HIV status). Similar proportions of women living with and without HIV were seropositive.

CONCLUSIONS

Rubella immunity was high among South African pregnant women living with and without HIV in the absence of rubella vaccination in the public immunization programme. However, a lower percentage of younger women had seropositive titres, indicating the need for routine rubella vaccination after an increase in vaccine coverage rates.

Co-administration of vaccines: a focus on tetravalent Measles-Mumps-Rubella-Varicella (MMRV) and meningococcal C conjugate vaccines

Simultaneous administration of different vaccines is a strategy to increase the possibility to receive vaccines at appropriate age, safely and effectively, reducing the number of sessions and allowing a more acceptable integration of new vaccines into National Immunization Programs (NIPs). Co-administration can be performed when there are specific indications in the Summary of Product Characteristics (SmPC) of the vaccines; but, in absence of these indications, the practice is possible if there are no specific contraindications nor scientific evidence to discourage simultaneous administration.

The aim of this work is to review the safety and efficacy of co-administration of the tetravalent measles, mumps, rubella, and varicella (MMRV) and the meningococcal C (Men C) conjugate vaccines after 12 months of age.

Several studies demonstrated that MMRV and Men C conjugate vaccines can be administered concomitantly without a negative impact on the safety and immunogenicity of either vaccines, inducing highly immunogenic responses.

Seroprevalence of measles, mumps, and rubella and genetic characterization of mumps virus in Khartoum, Sudan

BACKGROUND

In Sudan, neither mumps nor rubella vaccines are currently used and comprehensive data on the seroepidemiology of measles, mumps, and rubella (M.M.R), as well as information about circulating mumps virus genotypes, are lacking.

METHODS

In 2015/2016, dried blood spot samples were collected from 294 children, 153 adults from the general population, and 241 healthcare workers (HCWs) from Khartoum. The samples were investigated for M.M.R IgG antibodies using ELISA. Oral fluid samples from 16 clinical mumps cases collected in 2017 were characterized by RT-PCR and sequencing.

RESULTS

The seroprevalence of M.M.R antibodies among children was 93.5%, 63.6%, and 55.8%, while it was 93.5%, 90.8%, and 94.1% among adult volunteers and 99.2%, 97.1%, and 97.9% among HCWs. A high measles seroprevalence was observed among all children age groups, suggesting an effective control programme, while the mumps and rubella seroprevalence increased significantly with age (p<0.001), documenting active wild-type circulation. Our results demonstrated higher M.M.R seropositivity rates and IgG titres in HCWs compared to adult volunteers. Phylogenetic analysis showed the presence of genotype C mumps virus for the first time in Sudan.

CONCLUSIONS

The study findings provided new information on M.M.R epidemiology in Sudan, which may guide future control programmes in the country.

No. 203-Rubella in Pregnancy

OBJECTIVE

To provide an update on rubella and pregnancy so that health professionals remain aware of the potentially devastating effects on the developing fetus.

OUTCOMES

Rubella vaccination has been effective in virtually eliminating congenital rubella syndrome in Canada.

EVIDENCE

Medline, PubMed, and Cochrane Database were searched for articles published between 1985 and 2007.

VALUES

The quality of evidence was rated using the criteria described in the report of the Canadian Task Force on Preventive Health Care.

SPONSOR

The Society of Obstetricians and Gynaecologists of Canada.

RECOMMENDATIONS

Rubella virus-specific humoral immune responses and their interrelationships before and after a third dose of measles-mumps-rubella vaccine in women of childbearing age

In the U.S., measles, mumps, and rubella vaccination is recommended as two vaccine doses. A third dose of measles-mumps-rubella (MMR) vaccine is being administered in certain situations (e.g., identified seronegativity and during outbreaks). We studied rubella-specific humoral immunity (neutralizing antibody, enzyme-linked immunosorbent assay/ELISA IgG titer and antibody avidity) and the frequencies of antigen-specific memory B cells before and after a third dose of MMR-II in 109 female participants of childbearing age (median age, 34.5 years old) from Olmsted County, MN, with two documented prior MMR vaccine doses. The participants were selected from a cohort of 1117 individuals if they represented the high and the low ends of the rubella-specific antibody response spectrum. Of the 109 participants, we identified four individuals (3.67% of all study participants; 7.14% of the low-responder group) that were seronegative at Baseline (rubella-specific ELISA IgG titers <10 IU/mL), suggesting a lack of protection against rubella before receipt of a third MMR vaccine dose. The peak geometric mean neutralizing antibody titer one month following the third dose of MMR vaccine for the cohort was 243 NT₅₀ (CI; 241, 245), which is expected for a cohort with two doses of MMR, and the peak geometric mean IgG titer was 150 IU/mL (CI; 148, 152) with no seronegative individuals at Day 28. One-third of all subjects (31.8% for the neutralizing antibody; 30.8% for the IgG titer) experienced a significant boost (≥4-fold) of antibody titers one month following vaccination. Antibody titers and other tested immune-response variables were significantly higher in the high-responder group compared to the low-responder group. The frequencies of rubella-specific memory B cells were modestly associated with the antibody titers. Our study suggests the importance of yet unknown inherent biologic and immune factors for the generation and maintenance of rubella-vaccine-induced humoral immune responses.

No. 368-RUBELLA IN PREGNANCY

OBJECTIVE

To review the epidemiology, natural history, evaluation, and prevention of rubella infection during pregnancy. This will aid obstetric care providers in counseling their patients regarding potentially devastating effects on the developing fetus and the importance of vaccinating susceptible women as appropriate.

OUTCOMES

Outcomes evaluated include fetal rubella infection, maternal seroconversion and response to rubella-containing vaccines.

EVIDENCE

Medline, PubMed, EMBASE, and Cochrane databases were searched for articles in English on subjects related to rubella infection during pregnancy betweenn 1985 and 2017. Results were restricted to systematic reviews, randomized controlled trials/controlled clinical trials, and observational studies. Other (unpublished) literature was identified through searching the websites of health technology assessment and health technology assessment-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies.

VALUATION METHODS

The quality of the evidence is rated using the criteria described in the Report of the Canadian Task Force on Preventive Health Care (Table 1). Recommendations for practice are ranked according to the method described in this Report.

GUIDELINE UPDATE

The guideline will be reviewed 5 years after publication to decide if an update is required. However, if important new evidence is published prior to the 5-year cycle, the review process may be accelerated for a more rapid update of some recommendations SPONSOR: Society of Obstetricians and Gynaecologists of Canada.

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Long-Term Follow-Up of Antibody Titers Against Measles, Mumps, and Rubella in Recipients of Allogenic Hematopoietic Cell Transplantation

Outbreaks of viral infections, such as measles, are regularly observed and pose a serious threat to recipients of allogeneic hematopoietic cell transplantation (HCT). The questions of how long cellular and humoral protective host immunity persists, and whether donor immunity can be transferred has not been clarified. Here we present a retrospective analysis of humoral immunity-serial antibody titers against measles, mumps, and rubella-in 331 patients who underwent allogeneic HCT at our single center between 2002 and 2015. Associations between the loss of protective antibody levels and clinical patient characteristics and transplantation parameters were examined. In general, antibody protection against measles persisted longer, with 72% of patients maintaining sufficient titers at 5 years post-HCT even without revaccination, while at that time only 65% and 50% of patients had protective immunity against rubella and mumps, respectively. The great majority of donors were seropositive for all 3 viruses; however, it appeared that donor humoral immunity could not be transferred and had no impact on post-HCT serostatus. Rather, the most relevant factor for persistent protective antibody titers against measles and rubella was whether patients were born before the introduction of the respective vaccine and thus were immunized by the wild-type disease-inducing virus instead of the vaccine. Moreover, the presence of moderate and severe chronic graft-versus-host disease (GVHD) was associated with more rapid loss of immune protection. In contrast, underlying disease, intensity of the conditioning regimen, use of antithymocyte globulin, age, and graft source had no influence on antibody titers. Overall, our findings suggest that the majority of antibodies against measles, mumps, and rubella originate from residual host cells, whereas donor immune status appears to have no influence on antibody protection post-HCT.