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.

Impact of Gender-Specific Human Papillomavirus Vaccine Recommendations on Uptake of Other Adolescent Vaccines: Analysis of the NIS-Teen (2008-2012)

In the United States, human papillomavirus vaccination was routinely recommended for adolescent females in 2006 and provisionally recommended for adolescent males in 2009. We evaluated the hypothesis that gender-specific human papillomavirus vaccination recommendations would impact gender-specific uptake of other vaccines using National Immunization Survey-Teen public use data sets (2008-2012). Female adolescents had higher coverage than males of at least 1 other adolescent vaccine in 2008 (3.0% higher) and 2009 (4.3% higher). Gender differences abated in 2010, 2011, and 2012 (0.2%, 0.9%, and 0.4%, respectively). To evaluate unintended consequences of gender-based recommendations, countries with female-only human papillomavirus vaccination recommendations should evaluate gender-specific uptake of other adolescent vaccines.

Synthesis of Evidence to Characterize National Measles and Rubella Exposure and Immunization Histories

Population immunity depends on the dynamic levels of immunization coverage that countries achieve over time and any transmission of viruses that occur within the population that induce immunity. In the context of developing a dynamic transmission model for measles and rubella to support analyses of future immunization policy options, we assessed the model inputs required to reproduce past behavior and to provide some confidence about model performance at the national level. We reviewed the data available from the World Health Organization (WHO) and existing measles and rubella literature for evidence of historical reported routine and supplemental immunization activities and reported cases and outbreaks. We constructed model input profiles for 180 WHO member states and three other areas to support disease transmission model development and calibration. The profiles demonstrate the significant variability in immunization strategies used historically by regions and member states and the epidemiological implications of these historical choices. The profiles provide a historical perspective on measles and rubella immunization globally at the national level, and they may help immunization program managers identify existing immunity and/or knowledge gaps.

Childhood rubella encephalitis: diagnosis, management, and outcome

We to report clinical biological and radiologic features of rubella encephalitis in childhood and assess its prognostic impact. Our retrospective study was conducted in an intensive care unit of a university hospital in Sfax, Tunisia. Twenty-one children (age range, 1-15 years) were included. Median age was 9 years (lower and upper quartiles, 7-11 years). On admission, generalized maculopapular eruption was found in 17 cases (81%). Median Glasgow Coma Scale score was 7 (lower and upper quartiles, 7-8). Twenty patients (95.2%) experienced at least 1 episode of seizures. Sixteen patients (76.2%) developed a status epilepticus. The result for enzyme-linked immunosorbent assay detecting anti-rubella immunoglobulin (M) was positive in the serum and in the cerebrospinal fluid samples for all our patients. Magnetic resonance imaging (MRI) of the brain was performed on admission for 3 patients (14.3%) and within a median of 4 days (lower and upper quartiles, 2-6 days) for 8 patients. The test was normal in 6 cases. Two deaths were recorded (9.5%). Survivors had no neurological sequelae 6 months after intensive care unit discharge.

Phylogenetic analysis of rubella virus strains during an outbreak in São Paulo, 2007-2008

Rubella virus (RV) is an important human pathogen that causes rubella, an acute contagious disease. It also causes severe birth defects collectively known as congenital rubella syndrome when infection occurs during the first trimester of pregnancy. Here, we present the phylogenetic analysis of RV that circulated in São Paulo during the 2007-2008 outbreak. Samples collected from patients diagnosed with rubella were isolated in cell culture and sequenced. RV RNA was obtained from samples or RV-infected cell cultures and amplified by reverse transcriptase-polymerase chain reaction. Sequences were assigned to genotypes by phylogenetic analysis using RV reference sequences. Seventeen sequences were analyzed, and three genotypes were identified: 1a, 1G, and 2B. Genotypes 1a and 1G, which were isolated in 2007, were responsible for sporadic rubella cases in São Paulo. Thereafter, in late 2007, the epidemiological conditions changed, resulting in a large RV outbreak with the clear dominance of genotype 2B. The results of this study provide new approaches for monitoring the progress of elimination of rubella from São Paulo, Brazil.