Rubella-specific IgG Research Articles

One-point evaluation of children exposed to rubella infection In Utero in Maiduguri, North-Eastern Nigeria: A follow-up Study

Background: Rubella is a disease caused by a virus, rubella virus. Major obstetrics concerns are profound effects of the virus on developing fetuses, which may result in multiple congenital malformations. Although vaccination has reduced the incidence of rubella virus substantially; the World Health Organization (WHO) estimated that more than 100,000 cases of congenital rubella syndrome occur each year worldwide, most of them in developing countries. Diagnosis of rubella cannot be made on clinical grounds alone due to lack of specific symptoms or signs that are unique to the disease. Women infected with rubella during pregnancy are at increased risk of developing complication for the women and their fetuses. Some of these complications may not present at birth, but several years during childhood and later in life. Methodology: The main rubella sero-prevalence study was conducted in 2013, at the Department of Obstetrics and Gynaecology of the University of Maiduguri Teaching Hospital (UMTH), Maiduguri, Borno State, North-Eastern Nigeria. This is a follow-up descriptive study. The children of women who had significant titres of Immunoglobulin M antibodies, and who were negative for Immunoglobulin G antibodies were followed during their pregnancies and childbirth. The children born to these women who acquired rubella virus infection in mid pregnancy were reviewed at 10-11 years of age, and their current state of health is reported. Their biodata, educational status, rubella serostatus, state of health, and history of vaccination with measles were obtained. Results: There were 459 pregnant women who consented and participated in the main sero-prevalence study. Four hundred twenty-one women (91.7%) women tested positive for rubella-specific IgG antibodies, and of the remaining 38 women, 6 (15.8%) were positive for IgM rubella-specific antibody. All the patients with positive IgM antibodies were followed up till birth. All the pregnancies were carried to term and delivered in hospital. None of the neonates was found to have any congenital malformation at birth. At 10 years review of the six (6) children, 1 (16.7%) child developed cataract. None of the children developed cardiac, ear, or other complications of rubella. Five (5) children (83.3%) tested positive for both IgG, one (1) was negative (the child with cataract) for rubella antibodies. None had IgM rubella antibodies. All the children were enrolled in schools and their performance is at least average of their peers. Conclusion: None of the known types of congenital rubella syndrome was found in this study, this may be as a result of smaller number of infected pregnancies. It is recommended that inclusion of rubella vaccination in the National programme on Immunization protocol will be cost effective in the prevention of rubella-associated complication in children.

Rubella seroprevalence among unvaccinated school-aged children in Jos, North Central, Nigeria.

rubella poses a significant public health threat, particularly in developing countries, where congenital rubella remains a preventable concern. This cross-sectional study examined rubella seroprevalence among children aged 10 and under from May to September 2016 in Jos, Nigeria. using a multistage sampling method, eligible participants who had not been vaccinated against the rubella virus and consented to participate in the study were recruited across schools in the city. Rubella-specific IgG and IgM antibodies were detected from eluted serum collected from the participants using the enzyme-linked immunosorbent assay (ELISA). Data analysis and visualization was done using the R software version 4.3.1. of the 405 participants investigated in this study, 336 (82.96%) tested positive for rubella IgG, while 9 (2.22%) tested positive for rubella IgM. Factors such as age ≥ 5 years and lack of Western education showed significant associations with rubella seropositivity. this study highlights the seroprevalence of rubella IgG and IgM antibodies among children aged 10 and under in Jos, Nigeria. The significant associations between rubella seropositivity and factors such as age ≥ 5 years and lack of Western education underscore the necessity for an effective rubella vaccination program to prevent congenital rubella syndrome (CRS).

Multiplex Bead Assay for the Serological Surveillance of Measles and Rubella.

There is increasing interest in evaluating antibody responses to multiple antigen targets in a single assay. Immunity to measles and rubella are often evaluated together because immunity is provided through combined vaccines and because routine immunization efforts and surveillance for measles and rubella pathogens are combined in many countries. The multiplex bead assay (MBA) also known as the multiplex immunoassay (MIA) described here combines the measurement of measles- and rubella-specific IgG antibodies in serum quantitatively according to international serum standards and has been successfully utilized in integrated serological surveillance.

Seroepidemiology study of rubella virus antibodies among neonates and pregnant women at hospitals in Henan province, China.

Rubella virus infection can cause vertical transmission to the fetus during pregnancy. In China's Henan province, rubella surveillance needs to be well-established. In this research, a total of 1933 neonates and 2502 pregnant women were enrolled, and their sera for IgG and IgM antibodies against rubella were tested by chemiluminescence assay. Of 1933 neonates' sera tested, the seropositive of rubella IgG was 68.7%. The seroprevalence of rubella IgM in neonates was 0.4%. 30.9% of neonates had negative results for IgG and IgM antibodies. Two thousand five hundred and two pregnant women participated in the serosurvey, and 79.3% were rubella IgG positive. Rubella IgG seropositivity in pregnant women differed by age and number of births. 0.8% of the pregnant women had positive results for IgM against the rubella virus. The seronegative of rubella IgG and IgM antibodies in pregnant women was 19.8%. Due to the negative rubella-specific IgG antibody, many neonates remain at risk of rubella virus infection. Rubella virus continues to spread since some neonates and pregnant women with rubella-specific IgM antibody positive have been detected. Rubella vaccination may be introduced for childbearing-age women to increase immunity levels against rubella with periodic sero-surveillance.

HEALTHCARE WORKERS IN BULGARIA - ARE THEY PROTECTED FROM VACCINE-PREVENTABLE INFECTIONS?

Background: Healthcare workers (HCWs) are at increased risk of exposure to many viral infections, including vaccine preventable diseases (VPDs) such as measles, mumps and rubella (MMR) as compared to non-HCWs. Immunity of HCWs against these viruses is mandatory in a healthcare setting due to possible exposure from patients or colleagues. Aim: To provide an assessment of anti-measles, mumps and rubella IgG seropositivity among Bulgarian HCWs employed in hospitals and regional health inspectorates (RHI), as an indicator of protective immunity against MMR in this risk group. Materials and Methods: In the current study, 181 HCWs from Infectious Units in regional hospitals in the country, and HCWs from the RHI, involved in the monitoring and surveillance of MMR cases in Bulgaria were screened. Serum specimens from all participants were tested by a commercial indirect enzyme-linked immunosorbent assay (Anti-Measles, Anti-Mumps, Anti-Rubella IgG EIA-Euroimmun®, Germany) for presence of IgG antibodies against measles, mumps and rubella, as an indicator of protective immunity. Results: The study included 181 HCWs, 25 male and 156 female, aged 22 to 66 years. The average protective seroprevalence for measles, mumps and rubella was 82.9%, 76.2% and 92.3% percent, respectively. The highest share of negative results were obtained for mumps-specific IgG – 23.2% (42/181), followed by measles 16.6% (60/181) and rubella-specific IgG 7.7% (19/181). Regarding the age distribution, the highest number of HCWs non-immune to measles and mumps was found among the 31- 40-year olds, and against mumps – among the 41-50-year-olds. Conclusion: HCWs are at greater risk of contracting infections than the general population because of contact with sick patients or infectious material. Infected healthcare workers can spread nosocomial diseases to vulnerable patients with more severe illness, leading to complications and even death. Therefore, the vaccination status of HCWs must be strictly monitored.

Rubella seroprevalence among pregnant women in the region of Rabat, Morocco: a cross-sectional study

ObjectivesThe aim of the present research is to update data on the seroprevalence of rubella and to identify the associated risk factors among pregnant women in the Rabat region of...

Seroprevalence of Rubella IgG in Women of Reproductive Age Group in a Tertiary Care Teaching Hospital

Rubella is a highly contagious infection caused by the rubella virus. Mothers who develop rubella early in pregnancy have a 90% chance of transmitting the infection to their unborn babies. Adverse effects on the fetus include stillbirth and congenital rubella syndrome. Pregnant women are not regularly screened for rubella antibodies in government hospitals in Kerala. Therefore, to raise awareness of healthcare providers, it is necessary to collect epidemiological data on the seroprevalence of rubella in this vulnerable group. Several sociodemographic variables as potential predictors of immunity to rubella were also analyzed. A cross-sectional descriptive study was conducted at Govt TD Medical College in Alappuzha, Kerala, of 604 women of childbearing potential who attended the Out patient department of the Obstetrics and gynecology division for the year from June 2016 to June 2017. Rubella-specific IgG (Quantitative) ELISA was done on patients after obtaining informed consent and filling out a questionnaire through direct interview. The test sera were considered seropositive (>15 IU/ml), seronegative (<13 IU/ml), or intermediate (13 -15 IU/ml) as per the manufacturer’s instructions. Rubella seroprevalence in the study group was found to be 73.3%. Around 26.65% were nonimmune to rubella infection. About 27.4% of antenatal cases in the present study were susceptible to rubella. The primigravidae had lower seroprevalence(28.5%) than multigravidae. The percentage of seropositivity was found to increase with age. Our observations show that women of childbearing age are highly susceptible to rubella. High seroprevalence without regular childhood vaccination indicates continued infection transmission of the rubella virus in the community. Hence there is a need for proper sero surveillance in this group who has not been vaccinated, before conception to eradicate CRS and Rubella.

Rubella-specific IgG antibodies in non-pregnant women in Rivers State, Nigeria

Background: Rubella is a contagious virus-borne disease. The study aimed to test a cohort of non-pregnant women in Rivers State for rubella virus IgG antibodies and identify their susceptibility to the viral infection. Methods: The study included 92 consenting non-pregnant women attending Rivers State University Teaching Hospital in Rivers State. The sera were evaluated for detectable anti-rubella IgG antibodies using ELISA kits according to the manufacturer's instructions. Results: Eighty-five (92.4 per cent) of the 92 samples tested positive for rubella Immunoglobulin G antibodies, while 7 (7.6 per cent) tested negative. Rubella IgG seroprevalence was unrelated to age, education, or occupation. Conclusion: Given the high level of rubella IgG among non-pregnant women tested in Rivers State, it is likely that the virus is prevalent in the research area. As a result, a robust surveillance system and the organization of screening for anti-rubella IgG antibodies in pregnant women would be critical for future protection against the illness.

Influence of long-term storage of blood serum samples in a biobank for population-based seroepidemiologic studies

Aim. To assess the safety of IgG antibodies during long-term storage of blood serum samples using measles- and rubella-specific antibodies as an example.Material and methods. The study used serum samples from the collection of the Department of Epidemiology of the Gamaleya National Research Center for Epidemiology and Microbiologya, which were tested for measles- or rubella-specific IgG antibodies immediately upon admission to the laboratory, were frozen and stored at -70оC (n=180). The samples were reexamined after 20 months (n=90) and 6 years (n=90).Results. Reexamination after 20-month storage showed a decrease in the mean level of measles- and rubella-specific antibodies by 13,1% (from 0,36 (0,08-1,21) to 0,31 (0,02-1,2) IU/ml) and by 11,8% (from 151,4 (45-235) to 133,5 (72-198) IU/ml), respectively (p<0,05 for all). At the same time, the number of seronegative samples did not change. After a 6-year storage period, the mean level of measles-specific antibodies decreased by 33,8% (p<0,05) from 0,72 (0,4-1,79) to 0,34 (0,18-1,14) IU/ml and only two samples became seronegative. It was shown that the higher the IgG level in native samples, the more pronounced its decrease was during the second examination.Conclusion. Storage of serum samples in a biobank for 20 months at -70оC ensures the safety of measles- and rubella-specific IgG antibodies, and is the basis for the reliability of future studies.

Does the rubella immunoglobulin G affect the severity of COVID- 19?

Objective & aimThe coronavirus disease, so far (COVID-19) has brought about millions of infections and fatalities throughout the world. Our aim was to determine the correlation between rubella IGG titers with the severity COVID-19. Materials & methodsThis study was conducted among COVID-19 confirmed patients over 18 years of age. The disease severity levels were categorized by WHO interim guidance. The rubella-specific IgG antibody-titer spectrum was measured (within first 48 h of hospitalization) by enzyme-linked immunosorbent assay (ELISA).ResultIn a study of 46 inpatients with varying COVID-19 disease severity (mild, moderate, severe, and critical), we observed a negative correlation between rubella IgG antibody titers and COVID‐19 severity (P-Value = 0.017), There was an interaction between COVID-19 vaccination history and rubella IGG on severity COVID-19 (P-Value = 0.0015). There was an interaction between age group under 44 years (including national measles- rubella (MR) vaccination in Iran) and rubella IGG titers on severity COVID-19 too (p-value = 0.014).ConclusionIn conclusion, MR vaccination seems to have a positive effect in reducing the severity of the disease, emphasizing that, the important and separate effect of the IGG rubella (due to natural or extrinsic immunity) titers is determining.

Microbial antigen in human milk: a natural vaccine?

Microbial antigen in human milk: a natural vaccine?

Congenital Rubella syndrome cases (based on WHO criteria) one decade after Measle and Rubella vaccination campaign in Tehran; Iran.

Background: Active CRS surveillance is recommended strongly even in country with full rubella vaccination. Objective: Searching the CRS based on WHO criteria one decade after MR vaccination campaign (2003) Methods: a prospective case control study carried out in a third referral educational hospital (Rasoul Akram hospital) in Tehran, IRAN during five years (2013 -2018). From 89 CRS suspected infants (according to WHO criteria); serum samples were tested for rubella-specific IgG and IgM by ELISA method. Selected samples (positive Rubella IgM) were tested for rubella RNA by reverse transcriptase–polymerase chain reaction (RT–PCR). Findings: “Confirmed CRS” based on positive IgM was found in 5.6% (5/89) all were < 4 months old. Positive RT–PCR detected in 1.2 % (1/89) of “CRS suspected” infants.Except a good correlation between abnormal neurologic findings and positive IgM in “Confirmed CRS “cases, other clinical findings were not related to serologic tests. The “Compatible CRS” cases in the 31 patients who had primary negative IgM serology and did not have sufficient laboratory evidence to confirm CRS, but clinical symptoms favoured CRS. Conclusion: Despite MR vaccination in Iran, after one decade “confirmed CRS” and “compatible CRS” were diagnosed in 5 and 31 from 89 CRS suspected cases. The incidence of “confirmed CRS” in every 100 CRS suspected infants (after campaign) is 5.6 %; and 31 CRS Compatible cases are so important. Without active CRS surveillance; mild infection such as IUGR, hearing loss,heart abnormalities, impaired vision, and mental retardation even in developed country might be missed.Fetal infection is persistent which impose additional costs on the country..Another mass vaccination in women and girls is needed. Also, the antirubella IgG testing before pregnancy in women who were not vaccinated; vaccination of women before marriage /preganacy should be obligatory in order to prevent the CRS.

The seroprevalence of rubella virus in children between 0-15 years old in a hospital in Ankara province before expanded immunization program

Aim: In this study, it was aimed to determine the seroprevalence of rubella in children aged 0-15, who was admitted to Ankara Training and Research Hospital Pediatric outpatient clinic for various reasons between December 2001 and July 2002. In this descriptive study, it is thought that knowing the seroprevalence before the national vaccination program will be important for the evaluation of the future data. Material and Method: In this descriptive study; the seroprevalence of rubella in 1170 children aged 0-15 years was investigated. The age, gender, socio-economic level and number of siblings of the 954 cases included in the study were recorded on the prepared forms, and the history of infection was taken from their families. Rubella specific IgG levels from serum samples of the cases were measured by using the RADIM rubella IgG EIA kit with Micro-ELISA technique. Results: The average age of the children included in the study was found to be 76 } 49 months. Considering their gender, 56.9% (n=543) were male and 43.1% (n=411) were female. Considering their socio-economic levels; 550 children were in the low-income group; 393 children were in the middle-income group and 11 children were in the high-income group. When the distributions are evaluated according to the number of siblings; 14% (n=134) of the cases were a single child, 45% (n=426) had one sibling, 28% (n=267) had two siblings, and 13% (n=127) of the cases had ≥ 3 siblings. When evaluated in terms of rubella seroprevalence, 47.2% (n=450) of the cases had negative rubella IgG and 52.8% (n=504) of them had positive rubella IgG. According to the age the seropositivity showed a significant increase with the increasing age and remained constant at around 91% in the 13-15 age range (p <0.05). Conclusion: This study, conducted before the National Immunization Program in 2003, showed that a large part of our population is vulnerable to the risk of rubella infection. Considering that the seroprevalence increases with age in order to prevent rubella infection, which affects women of reproductive age and congenital rubella syndrome (CRS) seen in newborns in particular, it is important to vaccinate all children who have completed their 12th month and have entered the 48th month within the scope of the national vaccination program. The data of this study will guide us in evaluating the success of the program in the population, we provide healthcare services in the following years, as it reflects the situation before the Expanded Immunization Program (EIP).

Rubella Immunity among Italian Female Healthcare Workers: A Serological Study.

Rubella, also known as German measles or three-day measles, is an infectious disease caused by virus of the genus Rubivirus, which may be prevented by vaccination. The infection is potentially dangerous for non immune subjects, although 20–50% of infected subjects are asymptomatic. Healthcare workers (HCWs) have an increased potential exposure to rubella in comparison to the general population, putting them and their patients at risk of infection and its complications. In 2019, 20 cases of rubella have been reported in Italy. According to the Italian National Immunization and Prevention Plan, HCWs should provide a written certification of vaccination for rubella or serological evidence of protective antibodies. The aim of the study was to evaluate the rubella immunization status in female HCWs of the teaching hospital Policlinic Rome Tor Vergata (PTV) of childbearing age. For this purpose, we retrospectively checked the serologic values of rubella-specific IgG antibodies analyzing the clinical records of the HCWs of undergoing the occupational health surveillance program from January 1st to June1st 2020. Five hundred fourteen HCWs with a mean age of 23.19 (range 19–37, DS: 2.80) were included: 90.3% (464) showed a protective antibody titre. The mean value of the anti-rubella IgG was 49.59 IU/mL. Our study shows a non-protective anti rubella IgG titre in a substantial percentage of HCWs (9.7%). As vaccine protection decreases over the years and the risk of congenital rubella syndrome (CRS) in vaccinated subjects should not be underestimated, we suggest routine screening of the immunological status followed by the administration of a third dose of vaccine if the antibody titre becomes non-protective.

Rubella Specific IgG and IgM Antibodies among Infants before Rubella Vaccination in Dar es Salaam, Tanzania: A Cross-Sectional Study

Prevention of Rubella virus infection using rubella vaccine has been widely used in high-income countries contributing to the declining of congenital rubella syndrome. Before introduction of rubella vaccine in Tanzania October 2014, status of rubella specific antibodies in the infant was limited. This study was conducted to assess the rubella specific IgG and IgM antibodies among infants before receiving the vaccine.

Seroprevalence of Rubella Virus-specific Antibodies in Women and the Diagnostic Efficacy of Enzyme-linked Immunoassay and Rapid Immunochromatographic Tests.

IntroductionRubella is an infectious disease caused by the Rubella virus. The disease was previously called German measles and is transmitted through respiratory aerosols. Rubella causes both clinical and subclinical infections in children and young adults. Rubella virus has teratogenic capabilities and may cause severe complications in the fetuses of women who acquire Rubella viral infection during their pregnancy. The present study aims to evaluate the seroprevalence of anti-Rubella virus immunoglobulin (Ig) G and IgM antibodies in both pregnant and non-pregnant women and assess the diagnostic efficacy of enzyme-linked immunosorbent assay (ELISA) and rapid immunochromatographic tests.MethodsThe study included 240 females in the age range of 16-45 years. The study subjects included both pregnant women and non-pregnant women. After informed consent, 5 milliliters of blood was collected from each participant, and serum was separated and tested for the presence of antibodies (IgG and IgM) against the Rubella virus using both the traditional ELISA (Delta Biologicals, Pvt. Ltd., China) and a rapid ELISA-immunochromatographic test (ICT) (Span Biotech. Ltd., China). The data collected were systematically entered into Microsoft Excel sheets (Microsoft Corporation, Redmond, Washington) and were analyzed using SPSS Statistics for Windows, Version 17.0, 2008 (SPSS Inc., Chicago, Illinois).ResultsThe study revealed an overall seroprevalence of 31.66% for Rubella-specific IgG and IgM antibodies. Out of the 125 pregnant women included in the study, 49 (39.20%) were seropositive for Rubella IgG antibodies, and among the 115 non-pregnant women tested, 24 (20.86%) were positive for Rubella IgG antibodies. Four (5.26%) of the 76 seropositive women revealed IgM antibodies. The sensitivities of both the ELISA (40.61%) and rapid immunochromatographic (39.20%) tests were observed to be low and the specificities of both methods were similar (79.13%).ConclusionThe seroprevalence of Rubella-specific IgG antibodies was observed to be low as compared to the other regions of India. The low seroprevalence may predispose pregnant women to Rubella viral infection and may lead to increased incidences of congenital Rubella syndrome (CRS). Both the ELISA and immunochromatographic tests showed low sensitivity and similar specificities.

Recent trends in seroprevalence of rubella in Korean women of childbearing age: a cross-sectional study

ObjectivesThe aim of this study was to investigate the immunity against rubella using the serological status of rubella-specific IgG antibodies (antirubella IgG) in Korean women of childbearing age (15–49 years).DesignRetrospective...

Seroprevalence of rubella virus antibodies among pregnant women in the Center and South-West regions of Cameroon.

Rubella infection in early pregnancy can lead to miscarriages, fetal death, or birth of an infant with congenital rubella syndrome (CRS). In Cameroon, like in many developing countries, rubella surveillance is not well-established. The aim of this study was to determine the prevalence of rubella virus specific antibodies among pregnant Cameroonians. We conducted a cross-sectional study for rubella infection among pregnant women attending antenatal clinics in the Center and South-West regions of Cameroon. Demographic data and blood were collected and tested for rubella specific antibodies (IgG and IgM), and for the IgM positive cases, IgG avidity and real time PCR was done. From December 2015 to July 2017, 522 serum samples were collected and tested from pregnant women. The seroprevalence of rubella specific IgG was 94.4%, presumably due to immunity induced by wild-type rubella virus. The seroprevalence of rubella specific IgM was 5.0%, possibly indicating rubella infection. However, IgG avidity testing of the IgM positive cases detected high avidity IgGs, ranging from 52.37% to 87.70%, indicating past rubella infection. 5.6% (29/522) of the participants had negative results for IgG to rubella virus, indicating susceptibility to rubella infection. None of the participants had received a rubella containing vaccine (RCV), but 51% (266/522) of the pregnant women lived in a house with a child with records of at least one dose of RCV. Rubella virus RNA was not detected in the urine of any IgM positive case. Findings from this study show that rubella infection is significant in Cameroon. Some pregnant women are still susceptible to rubella infection. For a better management of rubella infection in pregnancy in Cameroon, consideration should be taken to investigate for IgG-avidity test in cases with positive rubella IgM result to distinguish between recent from past rubella infection.

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.

Seroprevalence and durability of rubella virus antibodies in a highly immunized population

BackgroundAlthough the administration of the measles-mumps-rubella (MMR) vaccine has been widespread in the United States for decades, gaps in vaccine coverage still persist for various reasons. The maintenance of herd immunity against rubella virus (RV) is important to controlling the spread and resurgence of rubella and congenital rubella syndrome. MethodsIn this study, we sought to assess the seroprevalence of RV-specific antibodies in an adult population from a defined geographic area in Olmsted County, MN, and the surrounding municipalities, with relatively high vaccine coverage and no documented evidence of circulating RV in the past 24 years. Rubella-specific IgG antibodies were measured by ELISA in a large set of serum samples (n = 1393) obtained from the Mayo Clinic Biobank. This cohort was 80.2% female and ranged from 20 to 44 years of age. ResultsIn total, 97.8% of subjects were seropositive for rubella-specific IgG antibodies, with a median titer of 40.56 IU/mL, suggesting a high degree of immunization; however, 2.2% of subjects were found to be seronegative. Interestingly, 25.1% of subjects were seropositive but had titers lower than 25 IU/mL, indicating either a population of low responders or individuals that could potentially be at risk of waning immunity. No significant associations or differences were found between RV-specific titers and demographic variables such as age, sex, or body mass index (BMI). ConclusionsA high rate of seropositivity for rubella was found among this young adult cohort, but a significant percent of the cohort had lower titers that may indicate poor initial vaccine response and potential risk if their antibody titers decline.