A case of congenital rubella syndrome and epidemiology of related cases in China, 2014-2023

Rubella is a major cause of congenital defects, and the presence of rubella infection in a pregnant woman may lead to fetal death or congenital defects known as congenital rubella syndrome(CRS). Since China has not yet established a national CRS surveillance system, the true incidence cannot be determined. To understand the disease burden and epidemiological characteristics of CRS cases in China, the article reports the first case of CRS in Quzhou, China, and conducts a retrospective analysis of related cases that have been reported in China over the past decade. Because the availability of rubella-containing vaccines (RCV) was not widespread in China before 2008, women of childbearing age born before 2008 are generally unvaccinated against RCV. Due to the lack of routine CRS monitoring and screening, CRS is underreported in China. Vaccination of nonimmune women of childbearing age with RCV and establishing a sensitive and timely case-based CRS surveillance system can accelerate the elimination of rubella and CRS.

Pregnant women and measles: we need to be vigilant during outbreaks

A number of countries including the UK are currently experiencing large outbreaks of measles affecting mainly young children but also adolescents and young adults. Women of childbearing age are a particular group of concern because the 1988 Wakefield Lancet paper, which falsely asserted a connection between the MMR vaccine and autism, was associated with a large and sharp decline in childhood MMR uptake over several years. This has left large cohorts of non-immune adolescents and young adults (born between 1998 and 2004), including young women who are now of childbearing age and remain susceptible to measles as well as rubella. Pregnant mothers are at higher risk of serious complications, such as pneumonia, with adverse pregnancy complications including fetal loss, premature birth, and neonatal death. Measles infection may also result in subacute sclerosing panencephalitis (SSPE), a very rare but very severe and invariably fatal neurodegenerative complication that typically manifests many years after acute measles infection but can have a short-onset latency with a fulminant course in pregnant women. Here, we summarise the epidemiology of measles infection, factors associated with the current measles outbreaks, as well as the risks and outcomes of measles, including SSPE, in pregnancy. We propose an algorithm for clinical management of measles infection in pregnancy. We also highlight the importance of early liaison with local health protection teams for risk assessment, diagnosis and management of suspected measles in pregnancy and close contacts as well as susceptible pregnant women exposed to a person with measles in the community.

Development of a real-time fluorescent reverse transcription loop-mediated isothermal amplification assay with quenching primers for rapid detection of rubella virus

Rubella virus infection during early pregnancy sometimes causes severe birth defects termed congenital rubella syndrome. Although there are safe and effective live-attenuated vaccines, rubella has only been certified as eliminated in the Americas within the six World Health Organization regions. Rubella remains an endemic disease in many regions, and outbreaks occur wherever population immunity is insufficient. There are two main methods for diagnosis of rubella: detection of anti-rubella IgM antibodies by enzyme immunoassay and detection of the viral genome by real-time RT-PCR. Both of these methods require substantial time and effort. In the present study, a rapid rubella detection assay using real-time fluorescent reverse transcription loop-mediated isothermal amplification with quenching primers was developed. The time required for the new assay was one-half that required for a real-time RT-PCR assay. The assay had 93.6% positive percent agreement and 100% negative percent agreement for clinical specimens compared with the real-time RT-PCR assay. The new assay is considered useful for diagnosis of rubella in areas where rubella is endemic.

Adverse events following Measles-Mumps-Rubella and varicella immunization: A safety profile analysis and comparison of different vaccination schedules based on the Italian Pharmacovigilance Network in the Veneto Region

Objective

The vaccines for measles, mumps, rubella and varicella (MMR and V) have been mandatory in Italy since 2017. Two different vaccination strategies are suggested for the first dose: trivalent MMR and a separate V vaccine or the tetravalent MMRV vaccine. Our aim is to compare the safety profile of MMRV and MMR-V vaccines through the passive adverse event reporting system in the Veneto region and to perform a case-by-case review of a few conditions of interest (febrile and afebrile seizures, ataxia, encephalitis, Guillain-Barré Syndrome, thrombocytopenia, neutropenia and Henoch-Schönlein Purpura). Age and sex differences were also explored.

Methods

We identified all reports following MMRV or MMR-V vaccination in the Veneto Region and received into the National Pharmacovigilance Network between 2007 and April 30, 2022.

Results

9,510 reports were retrieved, of which 5,662 (59.5 %) were related to MMRV and 3,848 (40.5 %) to MMR-V. No safety signals were detected supporting the evidence that MMRV and MMR-V vaccinations have a good safety profile. The reporting rate (RR) for serious events between 2007 and 2022 resulted in 13.67 per 10,000 administered doses for MMRV and 10.90 for MMR-V.

Conclusion

Passive surveillance data show a significantly higher rate of serious events for males 0-2 years old, both overall and stratified per vaccination strategy. Further studies are needed to confirm this observation. The analyses suggest that retrieved differences do not have a significant impact on the overall safety of both formulations.

Identifying the population susceptible to rubella in Japan, 2020: Fine-scale risk mapping

BACKGROUND

Rubella remains a public health challenge in Japan, impeding the attainment of herd immunity. Despite vaccination efforts since 1976, persistent outbreaks reveal a susceptibility gap in male adults born before 1995. Seroepidemiological surveys are pivotal in evaluating population immunity and identifying at-risk groups.

METHODS

This study aims to pinpoint high-risk areas for potential rubella outbreaks in Japan by merging seroepidemiological data from 2020 with population census information. Various data sources, including spatial demographic data, reported rubella and congenital rubella syndrome (CRS) cases, and traveler lodging statistics, were employed. Geospatial information for Japan's 230,300 small geographic areas was analyzed, and HI (hemagglutination inhibition) titers were examined by age and sex. Seroconversion was defined as an HI titer ≥ 1:32 or 1:16, indicating protective immunity. Geospatial maps illustrated the distribution of susceptible individuals per square kilometer, emphasizing high-risk urban areas like Tokyo and Osaka. Demographic shifts in the working-age population were assessed.

RESULTS

Susceptible individuals cluster in densely populated urban centers, persisting despite demographic changes. The study highlights areas at risk of increased susceptibility, particularly with an HI titer cut-off of 1:16. Foreign travelers pose potential rubella importation risks as travel volume to Japan rises. To prevent epidemics and congenital rubella syndrome burden, achieving and sustaining herd immunity in high-risk areas is crucial.

CONCLUSIONS

This study offers a comprehensive assessment of vulnerability in densely populated Japanese regions. Integrating population statistics with seroepidemiological data enhances our understanding of population immunity, guiding resource allocation for supplementary vaccination planning. To avert rubella epidemics, high-risk locations must bolster indirect protection through herd immunity, ultimately preventing congenital rubella syndrome.

Fundus imaging features of congenital rubella retinopathy

PURPOSE

To evaluate the clinical characteristics of congenital rubella retinopathy (CRR) with modern fundus imaging.

METHODS

Single-center case series. Eleven patients (2005-2020) at the Emory Eye Center with known or presumed CRR. Trained image readers reviewed fundus imaging (color fundus photography, widefield pseudocolor imaging, near-infrared reflectance imaging, autofluorescence imaging, and spectral-domain optical coherence tomography) for pre-specified features suggestive of CRR.

RESULTS

Eleven patients with confirmed (63.6%) or presumed (36.3%) CRR were identified. All were female with median (range) age of 53 (35-67) years. Six (54.5%) were born during the 1964-1965 United States rubella epidemic. All had congenital hearing loss. Two (18.2%) had a congenital heart defect. Eleven (50.0%) eyes had salt-and-pepper retinal pigmentary changes. Twenty-two eyes (100.0%) had irregularly distributed regions of speckled hypoautofluorescence. One eye (4.5%) had a presumed macular neovascularization.

CONCLUSION

Modern fundus imaging demonstrates characteristic features of CRR, even when pigmentary changes are not readily apparent on examination. Widefield autofluorescence findings of irregularly distributed speckled hypoautofluorescence are particularly revealing. This series of newly diagnosed adults with CRR may represent the milder end of the phenotypic spectrum of this condition, highlighting imaging findings that may aid in diagnostically challenging cases of CRR.

Risk of vaccine preventable diseases in UK migrants: A serosurvey and concordance analysis

Background

Vaccine preventable diseases (VPDs) such as measles and rubella cause significant morbidity and mortality globally every year. The World Health Organization (WHO), reported vaccine coverage for both measles and rubella to be 71 % in 2019, indicating an immunity gap. Migrants in the EU/EEA may be at high risk of VPDs due to under-immunisation and poor living conditions. However, there are limited data on VPD seroprotection rates amongst migrants living in the United Kingdom (UK).

Methods

We conducted an exploratory cross-sectional serosurvey amongst a sample of adult migrants living in Leicester, UK to: (a) determine seroprotection rates for measles, varicella zoster, and rubella in this group; (b) identify risk factors associated with seronegativity and, (c) understand if self-reported vaccine or diseases history is an effective measure of seroprotection. Participants gave a blood sample and completed a questionnaire asking basic demographic details and vaccine and disease history for the three VPDs. We summarised the data using median and interquartile range (IQR) for non-parametric continuous variables and count and percentage for categorical variables. We used logistic regression to establish predictors of seroprotection against these diseases. We examined the reliability of self-reported vaccination/disease history for prediction of seroprotection through a concordance analysis.

Results

149 migrants were included in the analysis. Seroprotection rates were: varicella zoster 98 %, rubella 92.6 % and measles 89.3 %. Increasing age was associated with seroprotection (OR 1.07 95 % CI 1.01-1.13 for each year increase in age). Migrants from Africa and the Middle East (aOR 15.16 95 % CI 1.31 - 175.06) and South/East Asia and Pacific regions (aOR 15.43 95 %CI 2.38 - 100.00) are significantly more likely to be seroprotected against measles as compared to migrants from Europe and Central Asia. The proportions of migrants unsure about their vaccination and disease history combined were 53.0 % for measles; 57.7 % for rubella; 43.0 % for varicella. There was no agreement between self-reported vaccination/disease history and serostatus.

Conclusion

Our findings suggest lower levels of seroprotection against measles in migrants living in Leicester, UK, with younger migrants and those from Europe and Central Asia more likely to lack seroprotection. A high proportion of surveyed migrants were unaware of their vaccination/disease history and self-reported vaccine/disease was a poor predictor of seroprotection against VPDs which is important for clinical decision-making regarding catch-up vaccination in this population. Our results, although derived from a small sample, suggest that there may be gaps in seroimmunity for certain VPDs in particular migrant populations. These findings should inform future qualitative studies investigating barriers to vaccine uptake in migrants and population-level seroprevalence studies aimed at determining individualised risk profiles based on demographic and migration factors.

Association between rubella vaccination response and long-term immune response to severe acute respiratory syndrome coronavirus 2 after BNT162b2 vaccination

In a previous study, we demonstrated an association between a low response to rubella vaccination and a decreased acquisition of anti-severe acute respiratory syndrome coronavirus 2 spike immunoglobulin G (anti-S IgG) shortly after the second dose of the BNT162b2 vaccine. The present study aimed to explore whether this association persists in terms of long-term antibody retention following the second dose of BNT162b2. Through multivariable analysis, we found a significant association between a low response to rubella vaccination and reduced anti-S IgG titers approximately eight months after the second dose of BNT162b2.

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.

Seroprevalence and risk factors for rubella infection in pregnant women attending a tertiary hospital in Kano-Nigeria

Introduction

rubella is a leading cause of vaccine preventable birth defects especially in developing countries. Acquisition of infection with the rubella virus in early pregnancy exposes the fetus to a very high chance of developing congenital rubella syndrome. The neonate is born with multiple abnormalities with the triad of congenital cataract, deafness and cardiovascular abnormalities like ventricular septal defect or patent ductus arteriosus. Limited data exist on the seroprevalence of rubella antibodies in pregnant women in Nigeria. The aim of this study was to determine the seroprevalence of rubella antibodies in pregnant women attending antenatal clinic in Aminu Kano Teaching Hospital, Kano State.

Methods

the study was a cross-sectional study involving one hundred and sixty-three pregnant women attending antenatal clinic of Aminu Kano Teaching Hospital in Kano, Nigeria. Interviewer administered questionnaire was used to collect sociodemographic data and risk factors. Blood samples were taken from consenting pregnant women during antenatal care and samples were subjected to antibody testing (IgG and IgM). Descriptive analysis was done for sociodemographic data and seroprevalence of rubella. Chi-square tests were used to determine associations.

Results

one hundred and sixty-three pregnant women were recruited for the study. The participants´ age ranged from 18 to 41 years with mean age of 27.60±5.7 years. The overall rubella seroprevalence was found to be 68.7%. The seroprevalence of specific anti-Rubella virus IgM and IgG was found to be 58.4% and 37.3% respectively while prevalence of having both anti-Rubella virus IgG and IgM in the women was found to be 26.4%. Non-formal education and immunodeficiency was found to be associated with rubella infection (P-value of 0.018 and 0.001 respectively).

Conclusion

the study found a high prevalence of anti-Rubella virus immunoglobulins in asymptomatic pregnant women attending antenatal care in our facility with immunodeficiency and non-formal education found to be significant risk factors.

A phase II/III randomised, comparative study evaluating the safety and immunogenicity of Biological E's live, attenuated Measles-Rubella vaccine in 9-12 month old healthy infants

Measles is a major cause of childhood mortality and one-third of the world's Measles deaths occur in India. Rubella causes lifelong birth defects (Congenital Rubella Syndrome). Although neither condition has a cure, the MR vaccination can successfully prevent both diseases. The safety of Biological E's live attenuated MR vaccine (BE-MR) was established in 4-5-year-old healthy children. This phase-2/3 study was conducted to assess the safety and immunogenicity of BE-MR in 9-12 month old healthy infants. Overall, 600 subjects were enrolled and equally randomized to receive either BE-MR (n = 300) or the comparator vaccine, SII MR-Vac™ (n = 300). Safety profile of BE-MR vaccine was comparable to SII MR-Vac™ with no severe or serious adverse events (AEs) reported across the study groups. The primary objective of demonstrating non inferiority by BE-MR vaccine compared to SIIL's-MR Vac™ was met. The proportion of subjects with ≥ 2-fold and ≥ 4-fold increase in antibody titre against Measles and Rubella in both the study groups was comparable. Overall, BE-MR vaccine elicited robust and protective immune response as demonstrated by high proportion of sero-protected subjects and a large increase in anti-Measles and anti-Rubella antibodies at day 42 and can be administered safely to infants below one-year of age. This study was prospectively registered with the clinical trial registry of India- CTRI/2016/07/007109.

Estimates of the global burden of Congenital Rubella Syndrome, 1996-2019

OBJECTIVES

Many countries introduced rubella-containing vaccination (RCV) after 2011, following changes in recommended World Health Organization (WHO) vaccination strategies and external support. We evaluated the impact of these introductions.

METHODS

We estimated the country-specific, region-specific, and global Congenital Rubella Syndrome (CRS) incidence during 1996-2019 using mathematical modeling, including routine and campaign vaccination coverage and seroprevalence data.

RESULTS

In 2019, WHO African and Eastern Mediterranean regions had the highest estimated CRS incidence (64 [95% confidence intervals (CI): 24-123] and 27 [95% CI: 4-67] per 100,000 live births respectively), where nearly half of births occur in countries that have introduced RCV. Other regions, where >95% of births occurred in countries that had introduced RCV, had a low estimated CRS incidence (<1 [95% CI: <1 to 8] and <1 [95% CI: <1 to 12] per 100,000 live births in South-East Asia [SEAR] and the Western Pacific [WPR] respectively, and similarly in Europe and the Americas). The estimated number of CRS births globally declined by approximately two-thirds during 2010-2019, from 100,000 (95% CI: 54,000-166,000) to 32,000 (95% CI: 13,000-60,000), representing a 73% reduction since 1996, largely following RCV introductions in WPR and SEAR, where the greatest reductions occurred.

CONCLUSIONS

Further reductions can occur by introducing RCV in remaining countries and maintaining high RCV coverage.

Measles and rubella elimination: protecting children through immunization in South-East Asia Region (SEAR)

The South-East Asia Region (SEAR) adopted the goal of "measles and rubella elimination by 2023". The goal was revised in 2019 to 'measles and rubella elimination by 2023' The strategies adopted to reach the goal included achieving ≥95% coverage with 2 doses of measles- and rubella-containing vaccine (MCV2; RCV2); establishing effective case-based surveillance supported by an accredited laboratory network; and implementing rapid response measures to control measles outbreaks. Of the 11 countries in the Region, to date five countries have eliminated measles and rubella and two more have controlled rubella. An estimated 242 million cases and 4.7 million deaths due to measles were averted between 2014 and 2022. The high-level political commitment, programmatic infrastructure and partnerships developed for the elimination of polio and maternal and neonatal tetanus played a critical role in this achievement. WHO, supported by key partners, provided technical support and strategic guidance for programmatic improvements, generated evidence to guide policy and strategic shifts, strengthened capacity of health workforce and conducted periodic programmatic reviews. However, unexpected occurrence of COVID-19 pandemic impacted vaccine coverage and quality of surveillance, thereby delaying achievement of the goal, and necessitating a revision of the target date of elimination.

Susceptibility of nursery teachers to measles, rubella, varicella and mumps in Japan

BACKGROUND

A guideline published in 2018 by the Ministry of Health, Labour and Welfare stipulated confirmation of the vaccine history of nursery staff members.

OBJECT

This study was conducted to elucidate nursery teachers' vaccine and infection histories for measles, mumps, rubella, and varicella through survey responses.

METHOD

After sending questionnaires through the mail to 5000 nursery teachers in November 2022, we received responses through December 2022. We measured the proportion of susceptibility in three ways. Additionally, we compared the proportions of susceptibility by disease by age class.

RESULTS

After receiving 1620 responses in all, the data of 1229 respondents under 50 years old were analyzed. Under the broad definition by which "no answer" was also regarded as unvaccinated or uinfected as well as "unknown," the proportions of susceptibility for measles, rubella, and varicella were higher: 22-23%. For mumps, the proportion was 42%. For varicella, they were 31% for respondents in their 30 s, and 14% for respondents in their 40 s. For mumps, the respective values were 58% and 26%.

DISCUSSION

Respondents assessed for this study were less susceptible and unknown in comparison with earlier studies investigating health care workers, school teachers, university students, and pregnant women.

CONCLUSION

The survey revealed that measles and rubella susceptibility was higher among respondents in their 30 s. However, it was higher for varicella and mumps among respondents in their 20 s.

Rubella virus genotype 2B endemicity and related utility of serum-based molecular characterization in Uganda

There are 13 globally recognized rubella virus genotypes of which only 2 (1E and 2B) have been detected recently. The largest percentage of all reported rubella virus sequences come from China and Japan with Africa reporting limited data. In a bid to address the lack of rubella genotype data in Uganda and the World Health Organization Africa region, we sought to characterize rubella viruses retrospectively using sera collected from suspected measles patients that turned out rubella IgM positive.Seven sequences belonging to genotype 2B sub-lineage 2B-L2c were obtained. These sequences clustered with other genotype 2B sequences previously reported from Uganda. None of the other genotypes (1E and 1G) reported from Uganda in the earlier years were detected. In addition, none of the sequences were obtained after the introduction of the measles-rubella containing vaccine. The above highlight the need for continuous rubella virological surveillance to confirm interruption of endemic rubella genotype circulation.

Efficacy of Rubella Vaccination after Co-Inoculation with Rhogam

Congenital rubella syndrome is a constellation of birth defects that can have devastating consequences, impacting approximately 100,000 births worldwide each year. The incidence is much lower in countries that routinely vaccinate their population. In the US, postnatal immunization of susceptible women is an important epidemiological strategy for the prevention of rubella as the Center for Disease Control (CDC) does not recommend administering this vaccine during pregnancy due to its nature as a live attenuated virus vaccine. However, concerns that the co-administration of rubella vaccine with other immunoglobins (i.e., Rhogam) could compromise vaccine efficacy has produced warnings that can delay the administration of rubella vaccination postpartum, leaving women susceptible to the disease in subsequent pregnancies. We aimed to address whether the co-administration of the measles, mumps, and rubella (MMR) vaccine and Rhogam decreased antibody responses compared to those receiving only MMR vaccination. This retrospective cohort study utilized clinical data from 78 subjects who received the MMR vaccine and Rhogam after delivery and 45 subjects who received the MMR vaccine alone. Maternal demographics, pregnancy complications and rubella status at the start of a subsequent pregnancy were recorded for analysis. Overall, the two cohorts had similar baseline characteristics; however, lower parity was noted in the participants that received both MMR vaccination and Rhogam. Making assessments based on maternal antibody IgG index for rubella during the next pregnancy, we observed that 88% of the Rhogam + MMR vaccine group had positive serology scores, which was not significantly different from the 80% rate in the MMR-vaccine-only cohort (p = 0.2). In conclusion, no differences were observed in rubella immunity status in subsequent pregnancies in those mothers given both the MMR vaccine and Rhogam concurrently. Given these findings, warnings against co-administration of vaccines in combination with Rhogam appear unwarranted.

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.

Viruses and autism: A Bi-mutual cause and effect

Autism spectrum disorder (ASD) is a group of heterogeneous, multi-factorial, neurodevelopmental disorders resulting from genetic and environmental factors interplay. Infection is a significant trigger of autism, especially during the critical developmental period. There is a strong interplay between the viral infection as a trigger and a result of ASD. We aim to highlight the mutual relationship between autism and viruses. We performed a thorough literature review and included 158 research in this review. Most of the literature agreed on the possible effects of the viral infection during the critical period of development on the risk of developing autism, especially for specific viral infections such as Rubella, Cytomegalovirus, Herpes Simplex virus, Varicella Zoster Virus, Influenza virus, Zika virus, and severe acute respiratory syndrome coronavirus 2. Viral infection directly infects the brain, triggers immune activation, induces epigenetic changes, and raises the risks of having a child with autism. At the same time, there is some evidence of increased risk of infection, including viral infections in children with autism, due to lots of factors. There is an increased risk of developing autism with a specific viral infection during the early developmental period and an increased risk of viral infections in children with autism. In addition, children with autism are at increased risk of infection, including viruses. Every effort should be made to prevent maternal and early-life infections and reduce the risk of autism. Immune modulation of children with autism should be considered to reduce the risk of infection.

Seroprevalence and prevention of hepatitis B, measles and rubella among healthcare workers in Dili, Timor-Leste

Introduction

The World Health Organisation recommends that healthcare workers (HCWs) are immune to measles and rubella, and those at risk of exposure are offered the hepatitis B vaccine. No formal programme for occupational assessment and provision of vaccinations to HCWs currently exists in Timor-Leste.

Methods

A cross-sectional study was undertaken to determine the seroprevalence of hepatitis B, measles and rubella among HCWs in Dili, Timor-Leste. All patient-facing employees at three healthcare institutions during April-June 2021 were invited to participate. Epidemiological data were collected by interview-questionnaire and a serum sample was collected by phlebotomy and analysed at the National Health Laboratory. Participants were contacted to discuss their results. Relevant vaccines were offered to seronegative individuals and those with active hepatitis B infection were referred for further assessment and management in a hepatology clinic as per national guidelines.

Results

Three-hundred-and-twenty-four HCWs were included (representing 51.3% of all eligible HCWs working at the three participating institutions). Sixteen (4.9%; 95% CI: 2.8-7.9%) had active hepatitis B infection, 121 (37.3%; 95% CI: 32.1-42.9%) had evidence of previous (cleared) hepatitis B infection, 134 (41.4%; 95% CI: 35.9-46.9%) were hepatitis B seronegative, and 53 (16.4%; 95% CI: 12.5-20.8%) had been vaccinated. Two-hundred-and-sixty-seven (82.4%; 95% CI: 77.8-86.4%) and 306 (94.4%; 95% CI: 91.4-96.7%) individuals exhibited antibodies to measles and rubella, respectively.

Interpretation

There are significant immunity gaps and a high prevalence of hepatitis B infection among HCWs in Dili Municipality, Timor-Leste. Routine occupational assessment and targeted vaccination of this group would be beneficial and should include all types of HCWs. This study provided an opportunity to develop a programme for the occupational assessment and vaccination of HCWs and forms the template for a national guideline.

Funding

This work was supported by the Department of Foreign Affairs and Trade, Australian Government [Complex Grant Agreement Number 75889].

Considerable doubt about rubella screening and vaccination among unvaccinated orthodox protestant women: a mixed-methods study

BACKGROUND

Women who are susceptible to rubella are advised to vaccinate against rubella to prevent infection in future pregnancies, and thus avert the risk of congenital rubella syndrome in their unborn child. Rubella outbreaks periodically occur in the under-vaccinated orthodox Protestant community in the Netherlands. The objective of this mixed-methods study was to determine and understand personal experience with rubella, perceived rubella susceptibility, and intention to accept rubella screening and vaccination among unvaccinated orthodox Protestant women. The ultimate aim of this study was to inform policy and practice and contribute to the prevention of cases of congenital rubella syndrome.

METHODS

A mixed-methods study was conducted combining an online survey and semi-structured interviews among unvaccinated Dutch orthodox Protestant women aged 18-40 years. Descriptive analysis was used for quantitative data. Qualitative data was analysed using codes and categories.

RESULTS

Results of the survey (167 participants) showed that most participants had personal experience with rubella (74%, 123/167) and 101 women (61%, 101/167) indicated they had had rubella themselves. More than half of the women were undecided whether to accept rubella susceptibility screening (56%; 87/156) or rubella vaccination (55%; 80/146). Qualitative findings (10 participants) showed that most women thought they were not susceptible to rubella. Indecisiveness and negative attitudes to accept rubella vaccination were related with religious arguments to object vaccination and with women's perception of absence of imminent threat of rubella. Furthermore, results showed presence of misconceptions among women in the interpretation of their susceptibility and high confidence in their parents' memory that they had experienced rubella as a child although no laboratory screening had been conducted.

CONCLUSIONS

In light of an imminent rubella outbreak in the Netherlands, a tailored education campaign should be prepared aimed at and established in cooperation with the under-vaccinated orthodox Protestant community. Health care providers should provide adequate information on rubella and support decision-making in order to stimulate women to make a deliberate and informed decision on rubella screening and, if necessary, subsequent vaccination.

Comparison of population-based measles-rubella immunoglobulin G antibody prevalence between 2014 and 2019 in Lao People's Democratic Republic: Impacts of the national immunization program

OBJECTIVES

We evaluated the effectiveness of the Lao People's Democratic Republic's measles-rubella immunization program using the seroprevalence from two cross-sectional surveys.

METHODS

The nationwide surveys occurred in 2014 and 2019 using a multistage cluster sampling, both requiring samples from 2184 individuals from 52 randomly selected villages. Immunoglobulin G titers, measured using enzyme-linked immunosorbent assay, were considered positive at ≥120 mIU/ml (measles) and ≥10 IU/ml (rubella). We calculated the vaccination-related reduction in the force of rubella infection and the number of congenital rubella syndrome cases averted in 2019.

RESULTS

We collected 2135 (women: 55.2%, mean age: 23.2 years) and 2001 (52.7%, 23.1 years) samples in 2014 and 2019, respectively. During 2014-2019, immunoglobulin G prevalence increased from 83.9% (95% confidence interval [CI]: 83.8-84.0) to 98.3% (97.7-98.8) for measles and from 75.4% (75.3-75.5) to 87.8% (86.4-89.2) for rubella. The most plausible reduction in the average force of rubella infection was 100% (95% CI: 28-100) since vaccination started, averting 78 (95% CI: 42-128) congenital rubella syndrome cases in 2019.

CONCLUSION

This is the first population-based study for measles and rubella at two different time points in developing countries. Measles and rubella seroprevalence increased significantly during 2014-2019, greatly exceeding the immunity thresholds for their elimination.

What's in a number? The value of titers as routine proof of immunity for medical students

OBJECTIVES

To assess the guideline concordance of medical school requirements for students' proof-of-immunity in the United States (US) and Canada.

METHODS

National guidelines for healthcare worker proof-of-immunity to measles, mumps, rubella, and varicella were compared to admission requirements for 62 US and 17 Canadian medical schools.

RESULTS

All surveyed schools accepted at least one recommended form of proof-of-immunity, however, contrary to national guidelines, 16% of surveyed US schools asked for a serologic titer, and only 73-79% US schools accepted vaccination as the sole proof-of-immunity.

CONCLUSIONS

The requirement of numerical, non-standardized serologic testing highlights an oversight in medical school admissions documentation. The requirement for quantitative values to demonstrate immunity is not practical from a laboratory standpoint, and is not needed to show individual immunity to these vaccine-preventable diseases. Until a more standardized process is adopted, laboratories will need to provide clear documentation and direction for quantitative titer requests.

Immune response to co-administration of measles, mumps, and rubella (MMR), and yellow fever vaccines: a randomized non-inferiority trial among one-year-old children in Argentina

BACKGROUND

In yellow fever (YF) endemic areas, measles, mumps, and rubella (MMR), and YF vaccines are often co-administered in childhood vaccination schedules. Because these are live vaccines, we assessed potential immune interference that could result from co-administration.

METHODS

We conducted an open-label, randomized non-inferiority trial among healthy 1-year-olds in Misiones Province, Argentina. Children were randomized to one of three groups (1:1:1): Co-administration of MMR and YF vaccines (MMR₁YF₁), MMR followed by YF vaccine four weeks later (MMR₁YF₂), or YF followed by MMR vaccine four weeks later (YF₁MMR₂). Blood samples obtained pre-vaccination and 28 days post-vaccination were tested for immunoglobulin G antibodies against measles, mumps, and rubella, and for YF virus-specific neutralizing antibodies. Non-inferiority in seroconversion was assessed using a -5% non-inferiority margin. Antibody concentrations were compared with Kruskal-Wallis tests.

RESULTS

Of 851 randomized children, 738 were correctly vaccinated, had ≥ 1 follow-up sample, and were included in the intention-to-treat population. Non-inferior seroconversion was observed for all antigens (measles seroconversion: 97.9% in the MMR₁YF₁ group versus 96.3% in the MMR₁YF₂ group, a difference of 1.6% [90% CI -1.5, 4.7]; rubella: 97.9% MMR₁YF₁ versus 94.7% MMR₁YF₂, a difference of 3.3% [-0.1, 6.7]; mumps: 96.7% MMR₁YF₁ versus 97.9% MMR₁YF₂, a difference of -1.3% [-4.1, 1.5]; and YF: 96.3% MMR₁YF₁ versus 97.5% YF₁MMR₂, a difference of -1.2% [-4.2, 1.7]). Rubella antibody concentrations and YF titers were significantly lower following co-administration; measles and mumps concentrations were not impacted.

CONCLUSION

Effective seroconversion was achieved and was not impacted by the co-administration, although antibody levels for two antigens were lower. The impact of lower antibody levels needs to be weighed against missed opportunities for vaccination to determine optimal timing for MMR and YF vaccine administration.

TRIAL REGISTRATION

The study was retrospectively registered in ClinicalTrials.gov (NCT03368495) on 11/12/2017.

Seroprevalence of Toxoplasma, Rubella and Cytomegalovirus in Women of Fertility Age in Our Region

Objective

Toxoplasma gondii (T. gondii), Rubella and Cytomegalovirus (CMV) infections can cause severe morbidity in the fetus when transmissed during pregnancy. In our study, it was aimed to examine the seropositivity rates for T. gondii, Rubella and CMV infections in women of childbearing age who applied to our hospital.

Methods

Anti-Toxoplasma IgG, anti-Toxoplasma IgM, anti-Rubella IgG, anti-Rubella IgM, anti-CMV IgG and anti-CMV were studied in women of childbearing age (18-49 years old) who applied to our hospital's outpatient clinics between January 2018 and December 2020. The tests were performed in our microbiology laboratory using the ELISA method on Architect i2000 (Abbott, USA) and COBAS e601 (Roche, Germany) devices.

Results

As a result of the data obtained, the percentages of IgM and IgG positivity for anti-Toxoplasma were calculated as 1.4% and 30.9%, respectively. Anti-Rubella IgM positivity was 0.7%, anti-Rubella IgG positivity was 91%, anti-CMV IgG positivity was 98.8%, and anti-CMV IgM positivity was 2%.

Conclusion

Having its own seroprevalence for each region has is important in terms of planning pregnancy screenings. The seropositivity rates in our region are in line with other studies in the country. Since CMV seropositivity is very high in the population and there is no effective treatment or vaccine, screening may not be not necessary. T. gondii and Rubella screenings can be recommended due to the lower immunity rates and the availability of vaccine and treatment options.

Shedding of rubella virus in postsymptomatic individuals; viral RNA load is a potential indicator to estimate candidate patients excreting infectious rubella virus

BACKGROUND

Since the first isolation of rubella virus (RuV) in 1962, comprehensive data regarding the quantitative evaluation of RuV shedding remain unavailable. In this study, we evaluated the shedding of viral RNA and infectious virus in patients with acute RuV infection.

STUDY DESIGN

We analyzed 767 specimens, including serum/plasma, peripheral blood mononuclear cells (PBMCs), throat swabs, and urine, obtained from 251 patients with rubella. The viral RNA load and the presence of infectious RuV were determined using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and virus isolation.

RESULTS

Virus excretion peaked 0-2 days after rash onset and decreased over time. The median viral RNA load dropped to an undetectable level on day 3 after rash onset in serum/plasma, day 2 in PBMCs, days 10-13 in throat swabs, and days 6-7 in urine. Infectious virus could be isolated for up to day 2 after rash onset in serum/plasma, day 1 in PBMCs, days 8-9 in throat swabs, and days 4-5 in urine. The minimum viral RNA load that allowed virus isolation was 961 copies/mL in serum/plasma, 784 copies/mL in PBMCs, 650 copies/mL in throat swabs, and 304 copies/mL in urine. A higher viral RNA load indicated a higher likelihood of the presence of infectious virus.

CONCLUSION

These findings would contribute to improve algorithms for rubella surveillance and diagnosis. In addition, this study indicates that the results of RT-qPCR enable efficient rubella control by estimating candidate patients excreting infectious virus, which could help prevent viral transmission at an early stage and eliminate rubella ultimately.

Association between a low response to rubella vaccination and reduced anti-severe acute respiratory syndrome coronavirus 2 immune response after vaccination with BNT162b2: a cross-sectional study

OBJECTIVES

Some vaccinated individuals fail to acquire an adequate immune response against infection. We aimed to determine whether mRNA severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination could induce a sufficient immune response against SARS-CoV-2 in low responders to other vaccinations.

METHODS

Using data from health-care workers who received two doses of the BNT162b2 vaccine (BioNTech/Pfizer), we conducted a single-centre, cross-sectional study to determine whether low responders to measles, rubella, and hepatitis B virus (HBV) vaccinations could acquire sufficient antibodies after SARS-CoV-2 vaccination. From May 2021 to June 2021, participants were tested for anti-SARS-CoV-2 spike (anti-S) IgG antibodies at least 2 weeks after the second dose of BNT162b2. The association between a low response to measles, rubella, and HBV vaccinations and the post-vaccination anti-S IgG titre was evaluated using the multivariable linear regression analysis.

RESULTS

All 714 participants were positive for the anti-S IgG titre (≥50.0 AU/mL) after two doses of BNT162b2 (median, 7126.8 AU/mL; interquartile range, 4496.2-11 296.8). There were 323 (45.2%), 131 (18.3%), and 43 (6.0%) low responders to measles, rubella, and HBV vaccinations, respectively. In the multivariable linear regression analysis, low responders to rubella vaccination had significantly low acquisition of the anti-S IgG titre after two doses of the BNT162b2 vaccine (standardized coefficient β, -0.110; 95% CI, -0.175 to -0.044).

CONCLUSIONS

A low response to rubella vaccination is a potential predictor of a reduced response to SARS-CoV-2 vaccination. Further studies are needed to determine whether a low response to rubella vaccination is associated with the durability of SARS-CoV-2 vaccination-induced immune response.

Congenital Rubella syndrome: A short report and literature review

Rubella infections are rarely seen where immunization programmes are in place. Congenital rubella syndrome is however still observed where the vaccination programme against rubella is not administered or interrupted. We present such a case, with typical clinical anomalies including congenital cataracts, sensorineural hearing loss and bone lesions. The diagnosis was verified by detection of rubella immunoglobulin M positivity in the mother in the first trimester and positive rubella serology in both baby and mother.

Epidemiological characteristic of rubella by age group during 12 years after the national introduction of rubella vaccine in Hangzhou, China

This study aimed to evaluate the implementation and impact of rubella-containing vaccine (RCV) by describing the rubella epidemiology and seroepidemiology in Hangzhou. We collected rubella cases of Hangzhou in the Information System for Disease Control and Prevention in China between 2009 and 2020, and performed a descriptive analysis. We applied a multi-stage stratified random sampling method to recruit participants for serological tests of rubella. Enzyme Linked Immunosorbent Assay (ELISA) was used to detect Immunoglobulin G (IgG) antibodies against rubella in serum samples. Univariate and multivariate analyses are used to detect the association between the level of rubella IgG and related factors. The incidence of rubella cases per million population decreased from 15.8 in 2009 to .1 in 2020. The proportion of rubella cases in women of childbearing age was higher than in men. A total of 4,362 subjects were tested serologically for rubella. The percentage of people whose rubella IgG antibody titers were above the minimum protective level (20 IU/ml) was 80.60% (95% CI: 79.4%–81.8%) and the geometric mean concentration (GMC) for rubella IgG was 58.34 IU/ml. The data indicated that Hangzhou had made good progress toward the elimination of rubella, whereas women of childbearing age still had a higher proportion of rubella cases, which might lead to increased risk of subsequent CRS. The positive rate and GMC of rubella IgG were significantly influenced by age and immunization history of RCV. Therefore, we should stress the importance of pushing forward the campaign for supplementary vaccination of rubella in adults.

A biotechnological review on patents applied to rubella diagnosis

BACKGROUND

Rubella, caused by the Rubella virus (RV), is considered a mild self-limited illness. However, RV has teratogenic potential. Laboratory investigation plays an important role in both diagnosis and surveillance of the disease. The main methods for diagnosing rubella are serological assays for the detection of specific IgM and molecular assays for detecting viral RNA. However, some laboratories perform IgG avidity testing, virus isolation and analysis of genetic sequence as tools to help rubella eradication. The importance of the diagnosis of rubella involves the appropriate treatment of the disease, because the rubella clinical symptoms may be similar to those of other diseases, and the population monitoring to avoid new emergent cases. This study addresses different methods of diagnosing rubella and contributes as a source of knowledge to assist health systems in controlling the disease.

OBJECTIVE

The main objective of this study was to review the available patents regarding rubella diagnosis published in intellectual property databases, and provides an overview of the technologies available for the diagnosis of rubella.

METHOD

The search strategy was based on the keywords searched separately or together using a Boolean operator either in the patent title or abstract the time interval was restricted to patents filed or granted from January 2009 until February 2022. The database used was Google Patents.

RESULTS

This study analyzed 24 patent documents regarding strategies for the diagnosis of rubella. Of these, 15 patents disclose strategies for detecting rubella antibodies, 7 patents the detection of rubella virus nucleic acid, and 2 patents the production of antibodies applied in rubella diagnosis.

CONCLUSION

Rubella is still a public health problem in some countries, mainly those in development, especially due to congenital rubella syndrome, which can cause malformation or fetal death. However, its diagnosis is challenging, due to similarity of symptoms with other diseases, and for this reason, laboratory diagnosis is essential. Studies like this encourage researchers and governments to invest in research to continue the development of new products, using different areas of biotechnology, to solve society's problems, especially diseases that have an impact on global health, such as rubella.

Antibody waning after immunosuppressive chemotherapy and immunomodulators, re-immunization considerations in pediatric patients with malignancy and chronic immune thrombocytopenic purpura

Introduction

Immunosuppressive chemotherapy increase the risk of vaccine-preventable infectious diseases in children; nevertheless, chemotherapy may result in delay or miss updated immunization schedules. The predictable antibody waning after incomplete primary immunization series may be intensified at the end of chemotherapy. This study aimed to investigate post-chemotherapy vaccine immunity waning at the end of immunosuppressive therapy in children with malignancy and hematologic disorders.

Materials and methods

Children with malignancies and hematologic disorders including chronic immune thrombocytopenic purpura (ITP) younger than 18 years old were enrolled from September 2015 to August 2019. Eligible patients who completed their treatment protocol for at least 6 months were recruited. The patient information, including sex, age at the date of diagnosis, number of chemotherapy sessions, underlying disease, and vaccination history, was taken by chart review using predefined questionnaires. The patient’s blood samples were obtained, and serum IgG antibody titer checked against diphtheria, tetanus, hepatitis B virus (HBV), mumps, measles, and rubella (MMR) were measured by enzyme-linked immunosorbent assay (ELISA).

Results

110 children receiving immunosuppressive chemotherapy were recruited. Forty-four (40%) of the children tested were girls and 66 (60%) were boys. The mean age of patients was 5.5 years with a range of 2 to 13 years. Of 110 studied children, 27.3% were seronegative for all antibodies. On average, patients undergo 19 episodes of chemotherapy. The mean chemotherapy sessions were significantly greater in children who were seronegative for all tested antibodies (mean: 36.2, 95% CI 33.16 to 39.24, p-value < 0.001). No statistically significant differences were observed regarding the patient’s sex and age between the seropositive and seronegative groups (p-value 0.513 and 0.060, respectively). Based on Poisson regression model analysis, the female gender was associated with 37% lower odds of seronegativity (incidence rate ratio (IIR): 0.63; [95% conf. interval: 0.39 to 1.01, p-value: 0.55]), while chemotherapy sessions 30 or more was associated with significant odds of seronegativity for all tested vaccines (IIR: 25.41; [95% conf. interval: 6.42 to 100.57, p-value < 0.001]).

Conclusion

Our results reemphasized planned catchup immunization in children undergoing immunosuppressive chemotherapy for malignancy, especially against tetanus, diphtheria, and hepatitis B at least 6 months after the end of chemotherapy sessions.

Changing demographics and immunity to vaccine preventable diseases in people with HIV in Ireland

BACKGROUND

HIV infection is associated with an increased risk of morbidity and mortality from vaccine preventable infections. This research describes, in the context of changing patient demographics, the seroprevalence of vaccine preventable viral infections among attendees of the largest centre for HIV positive patients in Ireland.

METHODS

Baseline serum IgG results for measles, mumps, rubella, varicella zoster virus (VZV) & hepatitis A, as well as hepatitis B sAg, cAb and sAb results, were retrieved for 2534 clinic attendees attending in 2018. Results were available for between 990 and 2363 attendees (39-93%), depending on the test, and were compared with 2013 clinic data.

RESULTS

There was a 35% increase in attendees in 2018 when compared to 2013. The largest increase was in attendees of South American origin. In 2018, males accounted for 73% of the entire cohort and the HIV acquisition risk for 48% of attendees was MSM. 47% of attendees were originally from Ireland. Among those tested, 33% were susceptible to at least one component of the MMR vaccine. 5% were VZV non-immune (significantly associated with younger age and the acquisition risk status of injection drug use). 21% were hepatitis A non-immune (significantly associated with younger age and being of European or South American origin). 32% were hepatitis B cAb seropositive (significantly associated with older age, injection drug use status and being originally from Africa). 3% demonstrated hepatitis B sAg positivity. 64% had hepatitis B sAb ≥ 10mIU.

CONCLUSION

In a cohort of attendees to an HIV clinic in a large urban setting, the susceptibility to several common vaccine preventable viral infections, in particular MMR and hepatitis A and B, was high. These results highlight the importance of proactive screening and immunisation to help protect this high risk patient group against vaccine preventable diseases.

Effect of vaccine program on IgG antibody titers for measles, rubella, varicella, and mumps in young adults in Japan: Survey between 2018 and 2021

INTRODUCTION

Improved routine immunizations in Japan have led to a reduction in vaccine-preventable diseases. Due to changes in the vaccination program, current young adults received their second vaccination for measles and rubella at different times depending on their birth year, and most of them have not been vaccinated against varicella and mumps. This study investigated the effect of vaccine programs on the immunity of people in Japan.

METHODS

Immunoglobulin G antibody (IgG) titers against four viruses were determined by enzyme immunoassay in 795 students at a medical university. Titers for measles and rubella were compared according to the students' birth dates (Group 1: April 2, 1990-April 1, 2000; Group 2: April 2, 2000).

RESULTS

The titers of students that satisfied the standard IgG values against measles, rubella, varicella, and mumps were 24.3%, 56.9%, 87.4%, and 47.2%, respectively. Measles and rubella titers were lower in group 2 (estimated mean period from last vaccination, 7.0 years) than group 1 (13.5 years) (p = 0.023 measles, p = 0.037 rubella), indicating attenuation of titers over time. Varicella and mumps antibody prevalence indicated that these infections were endemic, whereas rates of negative titers were higher than those for measles and rubella.

CONCLUSIONS

IgG titers against viruses were affected by vaccination programs. Declining titers after vaccination should be monitored when the diseases are almost eliminated and boosting is absent. Antibody testing is meaningful for recommending vaccinations and for surveillance of waning immunity. Continuous improvements of vaccination program should be considered to prevent and eliminate diseases.

Comparison of a chemiluminescence immunoassay and an enzyme immunoassay for detection of IgM antibodies against measles, mumps, rubella, cytomegalovirus (CMV), Epstein Barr virus (EBV), and human herpes virus (HHV) -1 and -2 infections

PURPOSE

Outbreaks of vaccine-preventable viral diseases have been increasingly reported globally over the past few years. The burden of congenital viral infections, their impact on physical and mental development and the resulting economic loss to the family and the community are also well known. IgM antibody detection has been convenient in the diagnosis of acute viral infections, particularly in settings with limited resources where molecular tests are not feasible.

METHODS

This is a comparative study between a chemiluminescence immunoassay (Liaison, DiaSorin, Saluggia, Italy) and an enzyme linked immunosorbent assay (ELISA) (Euroimmun, Lubeck, Germany) for the detection of IgM antibody against measles, mumps, rubella, CMV, EBV and HHV-1 and -2 viruses using a total of 345 samples. Results are expressed as agreement using kappa statistics.

RESULTS

In this study, CLIA is perfectly comparable to ELISA for the detection of IgM antibodies against measles (0.86) and mumps (0.92) with a moderate agreement for rubella (0.52), CMV (0.57), EBV (0.50), and HHV-1 and -2 (0.47) assays. However, a PABAK (prevalence-adjusted bias-adjusted kappa) showed improved agreement for rubella (0.64), CMV (0.65), EBV (0.60), and HHV-1 and -2 (0.88) assays.

CONCLUSIONS

IgM antibody assays (CLIA and ELISA) against measles and mumps virus can be comparably used depending on the laboratory setup, throughput and expertise.

Rubella antibodies in vertically and horizontally HIV-infected young adults vaccinated early in life and response to a booster dose in those with seronegative results

BACKGROUND

Very limited data are available on the persistence of rubella antibodies in vertically HIV-infected individuals who were vaccinated early in life.

METHODS

Prospective, cohort study on 4 groups of patients: 96 vertically HIV-1-infected individuals (v-HIV), 69 horizontally HIV-1-infected individuals (h-HIV), 93 healthy controls previously vaccinated for rubella (vac-CON) and 20 healthy controls with history of rubella disease (dis-CON). A blood sample was collected and rubella antibodies were analyzed by ELISA. Rubella antibodies above 10 IU/mL were considered protective. Individuals with seronegative results were offered an extra MMR vaccine dose and were tested at least 30 days afterwards.

RESULTS

Time since previous rubella vaccination was similar in v-HIV, h-HIV and vac-CON (16, 11 and 11 years; p = 0.428). v-HIV and h-HIV were also comparable regarding median CD4 T cells (613 and 614 cells/mm³; p = 0.599) and percentage on ART (93.8% and 98.6%; p = 0.135) at study entry. v-HIV had less individuals on virological suppression (63.5%) compared to 85.5% in h-HIV (p < 0.001). Rubella seropositivity and antibodies were significantly lower in v-HIV compared to h-HIV (32.3% vs 65.5%, 4.3 IU/mL vs 21.1 IU/mL; p < 0.001). Time interval between the last rubella vaccine dose and study entry was associated with an increase of rubella seronegativity, with a 7% higher chance of seronegativity for each one-year increase. After an extra MMR dose, 40 out of 48 (83.3%) seronegative individuals responded, with no significant difference among groups considering rubella seropositivity and antibody levels.

CONCLUSION

As vertically HIV-infected individuals reach adolescence and adulthood, assessment of vaccine antibodies can identify those who might benefit from an extra vaccine dose.

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

OBJECTIVE & AIM

The 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 & METHODS: This 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).

RESULT

In 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).

CONCLUSION

In 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.

Needle Fear among Children during Mass Measles Rubella (MR) Injectable Vaccination Campaign in North India: an Observational Study

The cross-sectional observational study evaluated the prevalence and predictors of needle-fear among school-going children during mass Measles-Rubella (MR) immunization campaign (year 2017) in the north Indian city of Chandigarh. Fear of needle was assessed using a single-item self-report global question, anxiety was assessed using the Likert scale (score 1-5) and the standardized "Children Faces Scale" where facial responses were graded from 0 to 4. Out of a total sample of 2568 school children, 1225 (47.7%) reported needle fear (95% CI: 45.8%-49.6%) on a global single item assessment. On an anxiety related Likert scale, 52.3% did not respond (mainly younger children) and among those who responded, 42.6% (523/1226) showed significant anxiety (score of ≥3 on Likert scale of 1 to 5). Finally, 17.4% children (95% CI: 15.9%-18.9%) (n = 446/2568) scored 2 or above (indicating significant needle fear) on the 'Children Faces Scale' during the actual vaccination procedure. The needle fear were significantly increased among girl students as compared to boys (adjusted OR 2.58; 95% CI: 2.05-3.24, p < 0.001) as well as children accompanied by their parents (adjusted OR 2.05; 95% CI:1.57-2.69, p < 0.001). On the other hand, needle fear was significantly lowered in children studying in private schools as compared to public school children (adjusted OR 0.45; 95% CI: 0.28-0.74, p = 0.002). The needle fear, which was an overriding concern in the minds of girls, children accompanied by their parents, and public-school students, must be proactively addressed for successful mass vaccination campaigns. These findings assume further importance with recent international roll out of COVID 19 vaccine.

Development of a rapid, internally controlled, two target, real-time RT-PCR for detection of rubella virus

Rubella surveillance in elimination setting relies on rapid molecular detection of the virus. In this study a multiplex real-time RT-PCR assay for the detection of rubella virus was validated. The assay includes three independent probes with unique reporter dyes for the simultaneous detection of the rubella viral coding regions for envelope glycoprotein E1 and non-structural p150 protein, and an endogenous control (human RNaseP). Using dilution series of synthetic RNAs, the limits of detection were determined to be at least 50 copies of rubella RNA. The assay is reproducible with low intra-assay and inter-assay coefficients of variation for both the E1 and the p150 targets. After testing 62 confirmed rubella positive and 165 rubella negative archival clinical samples, the sensitivity and specificity of the multiplex assay were 98.4 and 100%, respectively. No cross reactivity was identified with clinical specimens positive for eleven other viruses. This multiplex assay successfully detected nine viral genotypes including the predominant genotypes 1E, 1 G, 1 J, and 2B as well as the 1a vaccine genotype.

Seroconversion rates following 2 doses of measles- mumps- rubella vaccination given at the ages 12 and 18 months: data for possible additional dose at older age

Background

Despite high rate of vaccination coverage with 2-doses of measles containing vaccine among Iranian children, outbreaks of measles occurred among different age groups and fully vaccinated subjects. Although the main reason for these outbreaks is unknown, however, vaccine failure was supposed to be an important cause. This study was designed to determine the seroconversion rates to measles- mumps- rubella (MMR) vaccine currently in use among Iranian children.

Methods

This prospective study was conducted among healthy children older than 12 months who were candidates of scheduled MMR vaccination. Blood samples were obtained from each mother- infant pair just before vaccination, and from infants 4–6 weeks after MMR₁ and MMR₂ immunization. Collected sera were tested for specific lgG antibodies against MMR agents using ELISA method. The proportion of seroprotected subjects among mother- infant pairs before vaccination as well as the prevalence rates of seroconversion after MMR₁ and MMR₂ vaccination were calculated. Collected data were analyzed using descriptive statistical methods.

Results

During 22-months study period, 92 mother- infant pairs were participated. Seroimmunity rates against MMR viruses were 85.8%, 84.7% and 86.9% for mothers, and 3.2%, 2.1% and 1.0% for children, respectively. After MMR₁ vaccination from 52 seronegative children, 80.7%, 78.8% and 75% were seroconverted. These rates increased to 94.8%, 89.7% and 94.8% after the MMR₂ vaccination. Also, the specific immunity was enhanced among seropositive children.

Conclusion

Majority of the mothers and few infants were immune to MMR viruses prior to MMR₁ vaccination. Immune responses detected after MMR₁ injection, and overall seroconversion rates achieved after 2-doses of MMR vaccination were less than expected and inadequate to preserve long-term protection against MMR agents.

Lessons from ten years the prevalence of Congenital Rubella Syndrome (CRS) in young population living in a developing country, Tehran; Iran

BACKGROUND

A safe and effective rubella vaccine is available and prescribed in IRAN.

OBJECTIVE

This is a survey of CRS cases collected based on WHO criteria one decade after MR vaccination campaign (2003) Methods: This Multi-stage prospective/cross-sectional study was carried out in three stages in 3 educational hospitals in Tehran (Rasoul Aram, Akbar Abadi and Firoozabadi), In the first stage of study between 2011 and 2012 total 186 infants were evaluated and in the second stage of study, total 163 blood samples of infants with suspected INTRA UTERINE INFECTION were compared with a group of healthy matched infants. In the first and second stages, Rubella immunity (IgG&IgM) in cord blood was evaluated by Eliza method.

RESULTS

Despite MR vaccination in Iran, after one decade"confirmed CRS" and " compatible CRS" were diagnosed in 5 and 31 from 89 CRS suspected cases.

CONCLUSION

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 the developed country might be missed. Fetal infection is persistent, which imposes additional costs on the country.Another mass vaccination in women and girls is needed. Also, the anti-rubella IgG testing before pregnancy in women who were not vaccinated; vaccination of women before marriage /pregnancy should be obligatory in order to prevent the CRS.

Examination of scenarios introducing rubella vaccine in the Democratic Republic of the Congo

•

Serosurvey data suggest R₀ values for rubella in the DRC on the range 3 to 8.

•

Supplementary immunization activities provide multi-decade reduction in burden.

•

Post-vaccine introduction, burden will likely be concentrated in outbreaks.

Background

Rubella vaccine has yet to be introduced into the national immunization schedule of the Democratic Republic of the Congo (DRC); the current burden of congenital rubella syndrome (CRS) is unknown and likely to be high. An important consideration prior to introducing rubella containing vaccine (RCV) is the potential inverse relationship between RCV coverage and CRS incidence. Increasing RCV coverage will also increase in the average age of infection. Cumulative infections across all age groups will decrease, but the number of infections in age groups vulnerable to CRS may increase.

Methods

Rubella transmission dynamics in the DRC were simulated using a stochastic agent-based model of transmission. Input parameter values for known properties, demographic variables, and interventions were fixed; infectivity was inferred from seropositivity profiles in survey data.

Results

Our simulations of RCV introduction for the DRC demonstrate that an increase in CRS burden is unlikely. Continued endemic transmission is only plausible when routine immunization coverage is less than 40% and follow-up supplemental immunization activities have poor coverage for decades.

Conclusion

Increased vaccination coverage tends to increase the annual variability of CRS burden. Simulations examining low vaccination coverage and high mean CRS burden are outbreak prone, with multiple years of reduced burden followed by acute outbreaks. These outcomes contrast simulations with no vaccination coverage and high mean CRS burden, which have more consistent burden from year to year.

Seroprevalence of Rubella among Women of Reproductive Age in Iran: A Prisma-Based Systematic Review and Meta-Analysis

OBJECTIVE

Rubella is a highly contagious viral disease with a significant teratogenic effect. Various results have been published about the seroprevalence of rubella in Iran. A PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses)-systematic review and meta-analysis were conducted to assess the immunity against rubella in Iranian women.

METHODS

Eleven English and Persian electronic databases including PubMed, ScienceDirect, Scopus, Web of Science, Google Scholar, Embase, Scientific Information Database, Iran doc, Iran Medex, Magiran, and Medlib were searched using the keywords: Epidemiology, Prevalence, Rubella, Women, Childbearing age, Reproductive age, and Iran. A mathematician (NS) reviewed all steps for accuracy.

RESULTS

Out of 1,520 articles, 25 well-conducted studies with a total amount of 10,145 women were reviewed. The pooled prevalence rate of anti-rubella IgG was 84% (95% CI: 83%-86%). The highest prevalence rate of IgG was in Zahedan, Rasht, and Arak (each 100%), while the lowest prevalence was in Jahrom (54%). Subgroup analysis showed that from 1989 through 2012, the IgG prevalence rate increased from 78% (95% CI: 73-83%) to 99% (95% CI: 98 100%).

CONCLUSIONS

Although the vaccination program seems working in Iran, some peripheral regions may be a target to improve health care policies.

Multiplexed VaxArray immunoassay for rapid antigen quantification in measles and rubella vaccine manufacturing

Measles-containing vaccines (MCV), specifically vaccines against measles and rubella (MR), are extremely effective and critical for the eradication of measles and rubella diseases. In developed countries, vaccination rates are high and vaccines are readily available, but continued high prevalence of both diseases in developing countries and surges in measles deaths in recent years have highlighted the need to expand vaccination efforts. To meet demand for additional vaccines at a globally affordable price, it is highly desirable to streamline vaccine production thereby reducing cost and speeding up time to delivery. MR vaccine characterization currently relies on the 50% cell culture infectious dose (CCID₅₀) assay, an endpoint assay with low reproducibility that requires 10–14 days to complete. For streamlining bioprocess analysis and improving measurement precision relative to CCID₅₀, we developed the VaxArray Measles and Rubella assay kit, which is based on a multiplexed microarray immunoassay with a 5-hour time to result. Here we demonstrate vaccine-relevant sensitivity ranging from 345 to 800 IFU/mL up to 100,000 IFU/mL (infectious units per mL) and specificity that allows simultaneous analysis in bivalent vaccine samples. The assay is sensitive to antigen stability and has minimal interference from common vaccine additives. The assay exhibits high reproducibility and repeatability, with 15% CV, much lower than the typical 0.3 log₁₀ error (∼65%) observed for the CCID₅₀ assay. The intact protein concentration measured by VaxArray is reasonably correlated to, but not equivalent to, CCID₅₀ infectivity measurements for harvest samples. However, the measured protein concentration exhibits equivalency to CCID₅₀ for more purified samples, including concentrated virus pools and monovalent bulks, making the assay a useful new tool for same-day analysis of vaccine samples for bioprocess development, optimization, and monitoring.

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.

An 11-year trend of rubella incidence cases reported in the measles case-based surveillance system, Ghana

Introduction

rubella is vaccine-preventable and vaccination is the most cost-effective approach to control the disease and avoid the management of congenital rubella syndrome cases. Ghana introduced the rubella vaccine into the routine immunization program in 2013. Since then there have not been any evaluation of the epidemiology of rubella. We determined the disease trends and the population demographics of rubella cases, in the Ghana national measles case-based surveillance system.

Methods

we reviewed the measles case-based surveillance data from 2007 to 2017. Descriptive data statistics was done and expressed as frequencies and proportions. Chi-square test was used to establish associations.

Results

a total of 11,483 suspected cases for measles received and tested for measles IgM antibodies and 1,137(12.98%) confirmed positive for the period. Of these 10,077 were negative and 250 indeterminate for measles and tested for rubella and 2,090 (20.23%) confirmed positive for rubella IgM antibodies. More females (21.45%) were affected than males (19.48%). Majority of the confirmed positives were recorded in the urban areas. Children aged 15 years or less were mostly affected. There was a statistical difference between incidence cases and sex (χ2=6.03, p-value = 0.014), or age (χ2=283.56, p-value < 0.001) or area (χ2= 6.17, p-value = 0.013). Most infections occurred during the dry season.

Conclusion

children less than 15 years were mostly affected with majority being females. The highest incidence of cases was before the rains and occurred mostly in urban areas. The incidence of cases has declined significantly with the introduction of the rubella vaccine.

Cost of conducting Measles-Rubella vaccination campaign in India

A Measles-Rubella (MR) vaccination campaign was launched in India in a phased manner in February 2017 to cover children aged 9 months to 15 years. As evidence on campaign vaccine delivery costs is limited, the delivery cost for MR campaign from a government provider perspective was estimated in four Indian states, namely, Assam, Gujarat, Himachal Pradesh, and Uttar Pradesh. Costs were calculated in top-down and bottom-up approaches using data collected from 84 sites at different administrative levels and immunization partners in the study states from August 2019 to March 2020. All costs were presented in 2019 US$ and Indian Rupee (INR). The financial cost per dose of the MR campaign including all partner support ranged from US$0.16 (INR 10.95) in Uttar Pradesh to US$0.34 (INR 24.13) in Gujarat. In Uttar Pradesh, the full economic cost per dose was US$0.87 (INR 61.39). The key financial cost drivers were incentives related to service delivery and supervision, the printing of reporting formats for record-keeping, social mobilization, and advocacy. The financial delivery cost per dose estimated was higher than the government pre-fixed budget per child for the MR campaign, probably indicating an insufficient budget. However, the study found underutilization of MR budget in two states and use of other sources of funding for the campaign indicating the need for proper utilization of the campaign budgets by the states. Unit cost information generated from this study will be useful for planning, cost projections, and economic analysis of future vaccination campaigns in India.

Factors associated with adults' actions to confirm their own rubella immune status in Japan's drive toward rubella elimination: Cross-sectional online survey of non-healthcare workers in their 20s to 40s

Background

Rubella outbreaks occurred among adults in Japan in 2013-2014 and 2018-2019 due to immunity gaps. In response and aiming at rubella elimination by 2020, the government introduced countermeasures comprising supplementary immunization activities for voluntary testing of adult non-healthcare-related workers and vaccination of susceptible individuals. However, as of October 2020, rubella immunity testing and vaccination rates remained low. This study was conducted to identify factors associated with adults voluntarily confirming their rubella immune status, to help develop effective promotion activities for hard-to-reach and left-behind populations.

Methods

In this cross-sectional study, a general population sample of non-healthcare workers aged 20-49 years in Japan completed an online survey in November 2020. Univariate analysis was performed to examine associations of specific actions taken to confirm rubella immune status with social background characteristics, knowledge of rubella, and attitude to testing and vaccination. Log binomial regression analysis was performed to explore the associations following adjustment for social background characteristics.

Results

Among 1,854 respondents (927 men, 927 women), only 23.4% of men and 39.4% of women in their 20s to 40s have taken some action related to rubella prevention. Three major factors were associated with the targeted population having taken voluntary action: (1) knowing about testing for confirmation of immunity status (adjusted odds ratio [AOR] 4.29 men, 2.89 women), the rubella outbreak in 2013 among men in their 20s to 40s (AOR 2.79 men, 1.64 women), and congenital rubella syndrome (AOR 1.89 men, 3.10 women); (2) having acquaintances who were vaccinated against or tested for rubella (AOR 2.98 men, 1.95 women); and (3) having a positive attitude toward influenza vaccination (AOR 2.48 men, 1.83 women). Marriage, desire for pregnancy, and having children were weakly associated with taking action.

Conclusions

Currently, insufficient voluntary action is being taken by high-risk adult populations to close the identified immunity gaps. In this last mile to rubella elimination, our findings and suggested potential interventions via annual health check-ups and occupational health and public health initiatives could prove helpful in developing further countermeasures that actively promote and implement supplementary immunization activities targeting all adult generations.

Long-term survivors following autologous haematopoetic stem cell transplantation have significant defects in their humoral immunity against vaccine preventable diseases, years on from transplant

Current international guidelines recommend routinely vaccinating haematopoetic stem cell transplant (HSCT) recipients. Despite significant infection-related mortality following autologous HSCT, routine vaccination programmes (RVP) completion is poor. For recovered HSCT recipients, it is uncertain whether catch-up vaccination remains worthwhile years later. To determine potential susceptibility to vaccine preventable infections, we measured antibody titres in 56 patients, a median of 7 years (range 0-29) following autologous HSCT, who had not completed RVP. We found that almost all participants had inadequate titres against diphtheria (98.2%) and pneumococcal infection (100%), and a significant proportion had inadequate titres against measles (34.5%). Of those subsequently vaccinated according to available guidelines, many mounted adequate serological responses. These data suggest a pragmatic catch-up approach for autologous HSCT recipients who have not completed RVP is advisable, with universal vaccination against some pathogens (e.g. Streptococcus pneumoniae and diphtheria) and serologically-guided approaches for others (e.g. measles and varicella zoster virus).

A Review on Rubella Vaccine: Iran (1975-2010)

The first Attenuated rubella vaccine was developed by Parkman and Meyer in 1966. Ten years later in the 1975s, the rubella vaccine was developed in Razi Vaccine and serum research institute) RVSRI). In 1977, the rubella TAKAHASHI vaccine successfully passed the clinical trial and was initially used voluntarily only in the private sector. Since 1987, the administration of rubella as MMR (Measles/AIK-C; Rubella/TAKAHASHI; Mumps/HOSHINO) strain vaccine has been included in the immunization program in Iran. This review article focused on the development and production of the rubella TAKAHASHI/HDC vaccine in RVSRI. The herd immunity and rubella cases were investigated in the pre- and post-vaccine era. The effectiveness and proper coverage of the rubella vaccine led to the elimination of rubella from Iran in 2019. The current study aimed to assess local rubella vaccine manufacturing and its consequences on rubella elimination from Iran, using various search engines. A complete search was carried out in medical databases, including PubMed, Scopus, Web of Science, Scientific Information Database, IranMedex, Magiran, and Google Scholar. Within 1972-1975, Rubella TAKAHASHI/HDC vaccine was developed by RVSRI and successfully passed clinical trial in 1977. Over the four last decades (1980-2020), more than 40 million infants, young, and adults were vaccinated by million doses of local Rubella, measles-rubella (MR) or measles-mumps-rubella (MMR) vaccine in Iran. In 1972, the pre-vaccine era, the overall sensitivity to rubella infection was 69% in one-year-old Iranian children and 23% in childbearing women. The use of a safe, inexpensive, and effective vaccine increased herd immunity to 95% (85%-99%) in our country. During the last two decades, we have witnessed a 91% decline in the confirmed rubella cases, from 1124 in 2000 to 33 cases in 2018. The current article presented the process of vaccine development, tracked it through more than four decades, and discussed disease status before and after the rubella vaccine era, as well as the history of its elimination from Iran. The effectiveness of the local Razi Rubella vaccine resulted in a significant increase in seroprevalence in Iran. Expanded vaccination against rubella, usually with measles, has led to the elimination of Rubella from Iran as confirmed by World Health Organization in 2019.

Seroprevalence of measles and rubella antibodies in vaccinated and unvaccinated infants in the Lao People's Democratic Republic

BACKGROUND

Even though measles vaccination was introduced in the Lao PDR in 1984, coverage rates remain consistently low and outbreaks continue to occur frequently. This study was performed to investigate the seroprevalence of measles and rubella antibodies in vaccinated and unvaccinated children from Central Lao PDR.

METHODS

Antibody titres of 1090 children aged 8-29 months who were vaccinated at different levels of the health care system were assessed by ELISA. Bivariate and multivariable analyses were performed to identify factors affecting seropositivity against measles and rubella.

RESULTS

Among the vaccinated children, 67.5% in Vientiane Province and 76.4% in Bolikhamxay Province were double positive/borderline for measles and rubella IgG. A high proportion of unvaccinated children at both study sites (24.4% and 38.4%) were positive/borderline for measles and/or rubella. Time since vaccination <180 days, more than two siblings, and a mother who is a farmer/labourer were negatively associated with seropositivity.

CONCLUSIONS

A high prevalence of measles and rubella antibodies was found in unvaccinated children, indicating widespread circulation of both viruses and underreporting of cases. The high proportion of vaccinated children still susceptible to measles suggests problems with vaccine immunogenicity, emphasizing the need for regular evaluations of vaccine efficacy and management.

Attenuation of antibody titer of measles and rubella virus among university students of department of healthcare providers during 2015-2018 in Japan

BACKGROUND

In Japan, measles elimination was confirmed in March 2015. Nevertheless, some outbreaks with cases imported from abroad were reported even after certification. A large rubella outbreak has been occurring since 2017. This study examines measurement of the speed of attenuation of antibody titer for a measles virus comparison with rubella virus.

METHOD

Student subjects born from April 2, 1996 through April 1, 2000 were selected at Ibaraki Prefectural University of Health Sciences for this study: 177 for measles and 114 for rubella. They had available dates of additional immunization and antibodies in the following period and were judged as requiring additional immunization. We used enzyme immunoassay for IgG antibody testing. We regressed post-antibody titers of measles or rubella on pre-antibody titers and functions of duration between inoculation to post-evaluation. Functions of duration were selected according to the adjusted coefficient of determination.

RESULTS

For measles, only a linear term of duration or log of duration was found to be significant without the quadratic terms. For rubella, we selected a five-order linear model which indicated that titer after vaccination would converge to 19.2.

DISCUSSION

Results demonstrate that measles antibody decreased monotonically. If the pre-antibody titer was 15, vaccination raised titer quickly to 26; then it attenuated by 0.014 per day. Antibody titer is expected to be less than 16, which is the protection level of titer, after 704 days. For rubella, however, when pre-vaccination titer was evaluated at its average, the lower limit was 19.2. Therefore, protection can be maintained for a long time. This difference might reflect some circumstances of outbreaks of the respective diseases.

CONCLUSION

This report describes the speed of attenuation and the epidemiological situation. The speed of attenuation can be expected to rise. Therefore, additional vaccination every several years might be necessary to maintain a protection level if a disease is almost eliminated.