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.

Feasibility assessment of measles and rubella eradication

This report addresses the epidemiological aspects and feasibility of measles and rubella eradication and the potential resource requirements in response to the request of the Director-General at the Seventieth World Health Assembly held on May 31, 2017. A guiding principle is that the path toward measles and rubella eradication should serve to strengthen primary health care, promote universal health coverage, and be a pathfinder for new vision and strategy for immunization over the next decade as laid out in the Immunization Agenda 2030. Specifically, this report: 1) highlights the importance of measles and rubella as global health priorities; 2) reviews the current global measles and rubella situation; 3) summarizes prior assessments of the feasibility of measles and rubella eradication; 4) assesses the progress and challenges in achieving regional measles and rubella elimination; 5) assesses additional considerations for measles and rubella eradication, including the results of modelling and economic analyses; 6) assesses the implications of establishing a measles and rubella eradication goal and the process for setting an eradication target date; 7) proposes a framework for determining preconditions for setting a target date for measles and rubella eradication and how these preconditions should be understood and used; and 8) concludes with recommendations endorsed by SAGE.

The period from prodromal fever onset to rash onset in laboratory-confirmed rubella cases: a cross-sectional study

Background

In resource-limited settings, where rubella is endemic, it is difficult to determine which sporadic case should be tested for rubella. The study aimed to provide useful evidence to help screen rubella cases for real-time reverse transcriptase-polymerase chain reaction (RT-PCR) examination for rubella in resource-limited settings.

Method

Suspected rubella patients identified by a physician and brought to the notice of the Ryugasaki public health center or the Tsuchiura public health center were enrolled from April 2018 through December 2019. The inclusion criterion was a confirmed rubella diagnosis based on laboratory tests. We studied the distribution of the time from the onset of fever until the onset of rash.

Results

The study included 86 cases with simultaneous presentation of fever and rash. Twenty-nine cases had confirmed rubella based on the laboratory diagnosis. Among these, the time from the onset of fever until the onset of rash was limited to − 1 day to 2 days. The number of rubella cases was the highest when the onset of rash was on the following day of the onset of fever. Of the 78 patients who underwent the RT-PCR test, 48% tested positive for rubella among those with a time from the onset of fever to the onset of rash between − 1 day and 2 days (22 out of 46, 95% confidence interval 34–62%); no positive results (0 out of 30, 95% confidence interval - 14%) were seen in patients with a time from fever to rash onset ≥3 days.

Conclusion

The period from the onset of fever to the onset of rash was limited to − 1 day to 2 days among confirmed rubella patients. If the period from onset of fever to the onset of rash was ≥3 days for a patient, the likelihood of rubella was low.

Ultrasound diagnosis of infections in pregnancy

Pregnancy is a unique period in which several changes occur in the mother, to ensure that the semiallograft fetus is not rejected. Some of these changes decrease the immunity of the mother to infections. As such, some infections in pregnancy which may not ordinarily cause severe symptoms can be more severe in the mother and importantly some of these infections pose a danger to the fetus either directly or indirectly. In dealing with infections in pregnancy, attention should focus on both the consequences of the infection on the mother as well as in the fetus. Over the last decade, some of these infections have significantly influenced clinical practice. This series on Infections in Pregnancy in this journal provides a comprehensive cover of this topic. Here we focus on the fetal impact of infections in pregnancy and how ultrasound scan can help in identifying some of these infections and more importantly map out pathways for managing the pregnancies including counselling and additional invasive procedures.

10-Year survey on serum antibody positivity rates and titers for measles and rubella in healthcare workers; an observational study at a Japanese university hospital

BACKGROUND

We evaluated the effect of the two-dose vaccination strategy, which has been a widely adopted as childhood routine schedule worldwide to acquire herd immunity, on healthcare workers (HCWs) in Japan.

METHODS

Between 2010 and 2019, antibody titers for measles and rubella were measured annually among newly employed HCWs at Osaka University Hospital, Japan, using Enzygnost® assays (Siemens Healthcare Diagnostics Co. Ltd., Marburg, Germany). The data were categorized by age to compare the antibody positivity rates and antibody titers among no-vaccine, single-dose, and two-dose groups.

RESULTS

Over the 10-year period, the annual antibody positivity rates for measles and rubella were 84.0%-95.3% and 90.0%-94.5%, respectively, without any particular trend. The antibody titers for measles (median [interquartile range]: 8.4 [3.9, 20] vs. 6.1 [3.5, 12]) and rubella (11 [5.5, 20] vs. 6 [3.7, 11]) were statistically lower (p < 0.001) in the two-dose generation than in the single-dose generation.

DISCUSSION

A shift from single-dose to two-dose vaccination did not yield an increase in antibody positivity rates for both measles and rubella among HCWs. Notably, antibody titers were significantly lower in the two-dose generation.

CONCLUSION

Despite several limitations, our data suggests a paradoxical vulnerability in young HCWs who received the two-dose vaccination in a view of sero-positivity rates.

Dynamics of maternally transferred antibodies against measles, mumps, and rubella in infants in Sri Lanka

BACKGROUND

Determining the dynamics of maternally transferred antibodies against measles, mumps, and rubella infections in infants is important for making evidence-based policy decisions regarding the timing of vaccination.

METHODS

The levels of serum immunoglobulin G (IgG) developed against measles, mumps, and rubella infections were assessed using commercial ELISA kits in mother-newborn pairs (n = 294) and 6-12-month-old infants (n = 280) recruited from Colombo District, Sri Lanka. Antibody levels of mothers and their newborns were assessed with respect to sex and parity. Antibody levels and the protection conferred were assessed in a sample of infants who completed 6-12 months of age in relation to their age and sex. Antibody levels were compared between different age and sex groups using the Mann-Whitney U-test, and correlations of antibody titers were performed using the Spearman correlation test.

RESULTS

The prevalence rates of seropositivity for measles, mumps, and rubella were 91.5%, 89%, and 88%, respectively, in mothers, and 95%, 91.5%, and 93%, respectively, in their newborns. The newborns had mean IgG levels exceeding those of the mothers (P < 0.001). Mothers with natural infections had higher antibody levels compared to vaccinated mothers, which resulted in a higher level of maternal transfer. All of the infants who were 9-10 months of age or older were seronegative for measles, all of those who were 10-11 months of age or older were seronegative for rubella, and all of those who were 11-12 months old were seronegative for mumps.

CONCLUSIONS

The maternal transfer of antibodies to newborns is efficient and renders protection until the infants are 6-7 months old in the case of mumps and rubella and 7-8 months old in the case of measles. Hence infants remain vulnerable to infections before the first dose of the MMR vaccine.

Burden of Congenital Rubella Syndrome (CRS) in Bangladesh: Systematic Review of Existing Literature and Transmission Modelling of Seroprevalence Studies

BACKGROUND AND OBJECTIVES

Congenital Rubella Syndrome (CRS) is the leading cause of vaccine-preventable congenital anomalies. Comprehensive country-level data on the burden of CRS in low and middle-income countries, such as Bangladesh, are scarce. This information is essential for assessing the impact of rubella vaccination programs. We aim to systematically review the literature on the epidemiology of CRS and estimate the burden of CRS in Bangladesh.

METHODS

We conducted a systematic review of existing literature and transmission modelling of seroprevalence studies to estimate the pre-vaccine period burden of CRS in Bangladesh. OVID Medline (1948 - 23 November 2016) and OVID EMBASE (1974 - 23 November 2016) were searched using a combination of the database-specific controlled vocabulary and free text terms. We used an age-stratified deterministic model to estimate the pre-vaccination burden of CRS in Bangladesh.

FINDINGS

Ten articles were identified, published between 2000 and 2014, including seven crosssectional studies, two case series and one analytical case-control study. Rubella seropositivity ranged from 47.0% to 86.0% among all age population. Rubella sero-positivity increased with age. Rubella seropositivity among women of childbearing age was 81.0% overall. The estimated incidence of CRS was 0·99 per 1,000 live births, which corresponds to approximately 3,292 CRS cases annually in Bangladesh.

CONCLUSION

The estimated burden of CRS in Bangladesh during the pre-vaccination period was high. This will provide important baseline information to assess the impact and cost-effectiveness of routine rubella immunisation, introduced in 2012 in Bangladesh.

Age-stratified seroprevalence of vaccine-preventable infectious disease in Saravan, Southern Lao People's Democratic Republic

BACKGROUND

Lao People's Democratic Republic has frequent outbreaks of vaccine-preventable diseases (VPD). This study aimed to determine susceptibility and exposure to VPD in Saravan, a rural province with high ethnic diversity and some of the poorest health indicators nationwide.

METHODS

Patients from three district hospitals and one provincial hospital were enrolled. Serum was tested by ELISA for IgG against hepatitis B virus (HBV), tetanus, diphtheria, measles, and rubella.

RESULTS

The study enrolled 2463 participants aged 5-90 years. Exposure to HBV was 33.2% and increased with age up to 62.4% of those aged >50 years. HBV surface antigen prevalence was 5.7% in males and 2.4% in females; 9.9% had serology compatible with vaccination. Seroprevalence of protective anti-tetanus antibodies was 46.3% overall. Protective anti-diphtheria seroprevalence was 40.5%. Anti-measles seroprevalence increased from 16.7% in those aged 5-10 years to 97.7% in those aged >50 years. Anti-rubella seroprevalence was 93.0% overall. There were differences in seroprevalences between sex, districts and ethnicity.

CONCLUSIONS

Routine infant vaccination needs strengthening in order to close the immunity gaps. High burden of HBV infection should be addressed by increasing birth dose vaccine coverage. Regional and ethnic differences need to be investigated to enable a targeted approach to vaccination.

Measles and rubella serosusceptibity among population vaccinated with different schedules: the potential impact on measles-rubella elimination in Iran

BACKGROUND

Iranian children were vaccinated with the scheduled two doses of monovalent measles vaccine (mMV) from 1984. In December 2003, a nationwide campaign of measles-rubella (MR) immunization was established to vaccinate 5-25 year- old individuals. In 2004, the mMV was replaced with measles- mumps- rubella (MMR) vaccine. Despite the high vaccination coverage, the outbreaks of measles still occur in the country. In this Study, the MR immunity status of various age groups, vaccinated with different schedules was investigated, and the immunologic response of seronegative subjects to revaccination was examined.

METHODS

This cross-sectional study was conducted among 7-33-year-old healthy individuals with a documented history of measles vaccination from November 2017 to June 2018. The subjects were categorized as follows: group A, including 20-33 year-old individuals; vaccinated with 1-2 doses of mMV at ages 9 and 15 months, and revaccinated with MR, group B, including 15-19-year-old individuals, vaccinated with two doses of mMV at 9 and 15 months of age, and received additional dose of MMR upon school entrance, group C, including 11-14 year-old individuals, vaccinated with two-doses of MMR at the ages of 15 months and 6 years, and group D, including 7-10 year-old individuals vaccinated with two-doses of MMR vaccine at the ages 12 and 18 months, respectively. Levels of antimeasles- antirubella IgG antibodies in the collected sera were measured. Also antimeasles- antirubella IgM and IgG of seronegative individuals were reexamined at 4-6 weeks after MMR revaccination. The collected data were analyzed using descriptive statistical methods.

RESULTS

A total of 635 individuals were investigated in this study. Group A, 98; group B, 295; group C, 139; and group D, 103 persons. Overall, 12.3 and 18.4% of the population were seronegative for measles and rubella antibodies. This rate varied greatly between the 4 groups: group A, 0/0-2%; group B,15.2-25.0%; group C,11.5-17.2%; and groupD,14.6-18.4%. After revaccination, 92 and 94.9% of seronegative individuals showed IgG response to measles and rubella vaccines, respectively.

CONCLUSION

Despite the high coverage rate of M-R containing vaccines, a significant number of vaccinated subjects were seronegative for measles and rubella, possibly because of secondary vaccine failure; this may negatively affect measles-rubella elimination targets in the country. If these findings are confirmed in similar future studies, a more robust regional/national supplementary immunization activity will be considered.

Persistence of anti-rubella immunoglobulin G antibody titers in young adults involved in a short-term periodic immunization in Japan

In Japan, several rubella outbreaks in adults have erupted due to insufficient immunity against rubella virus (RUBV). Although selective immunization is being promoted in addition to a routine rubella vaccine program as a rubella eradication strategy, serosurveillance against RUBV needs to be implemented in the generations corresponding to the transition period of vaccination. In this study, a survey of anti-rubella immunoglobulin G (IgG) antibody titers was conducted among young adults involved in the transitional periods of the routine rubella vaccine program. Serosurveillance was performed in 370 healthy young adults aged 18-20 years, and their serum samples were analyzed using an enzyme immunoassay to determine rubella-specific IgG antibody titers. Although multiple regression analysis revealed significant differences only in medical history, more than 90% of participants exhibited seropositivity, excluding those who received single-dose vaccine alone. Based on elapsed periods after the last vaccination, rubella-specific IgG antibody titers in less than a 6-year period were higher compared to that in the more than 10-year period. Although almost all study participants in the transitional period had seropositivity, the results may indicate that the persistence of seropositivity is related to past rubella outbreaks.

Immunity and Vaccination Against Measles, Mumps, and Rubella in Adult Allogeneic Hematopoietic Stem Cell Transplant Recipients

Large outbreaks of measles or rubella occasionally occur around the world, and measles infection can be severe and even fatal in transplant patients. However, limited data are available on immunity to measles, mumps, and rubella (MMR) in adult patients after allogeneic stem cell transplantation (allo-HCT). The aim of this study was to evaluate the immune status against MMR and the effects of vaccination against MMR in adult patients after allo-HCT. A total of 135 adult patients who were alive without relapse and new malignancy at 2 years after allo-HCT were included in this study. We measured IgG antibody to MMR before allo-HCT and annually thereafter. The probabilities of being seropositive to measles, mumps or rubella after allo-HCT were estimated according to the Kaplan-Meier method and compared among groups with the log-rank test. The probability of being seropositive at 2 years after allo-HCT in patients who were seropositive before allo-HCT was 60.6% for measles, 39.7% for mumps, and 52.2% for rubella. History of chronic graft-versus-host disease tended to be a risk factor for the loss of immunity against measles (hazard ratio [HR] 1.69, P = .064) and rubella (HR 1.75, P = .056). To predict the loss of immunity against MMR at 2 years after allo-HCT, we defined the following cutoff values for the IgG index before HCT: 18.2 for measles, 5.3 for mumps, and 21.4 for rubella using a receiver-operating characteristics curve. The lower-IgG groups experienced a significant loss of seropositivity at 2 years (39% versus 82% for measles, P < .001; 13% versus 59% for mumps, P < .001; and 33% versus 90% for rubella, P < .001). After this loss of immunity, 25 patients received a single vaccination against MMR. The seroconversion rates were 64%, 36%, and 72% for measles, mumps, and rubella, respectively. Loss of immunity to MMR commonly occurs in the first several years after transplantation. In the patients who lose the immunity, the seroconversion rate after 1 dose of MMR vaccine given at ≥2 years after transplantation is suboptimal.

Factors associated with participation in an ongoing national catch-up campaign against rubella: a cross-sectional internet survey among 1680 adult men in Japan

Background

Since 2019, aiming to eliminate periodic rubella outbreaks, the Japanese government has provided a rubella immunization program targeting men born in fiscal years 1972 to 1978, who lacked the opportunity to be vaccinated against rubella in childhood. This study aimed to explore the factors associated with participation in the rubella vaccination program among the first-year target population in 2019.

Methods

A total of 11,754 adult men in Japan born in fiscal years 1972 to1978 living in seven rubella epidemic areas (Tokyo, Chiba, Kanagawa, Saitama, Aichi, Osaka, and Fukuoka) were selected from a list of a survey agency and invited to complete an Internet questionnaire in March 2020. Recruitment ended when the participants reached 1680 individuals. Multivariable log binomial regression analyses were performed to explore the association between awareness of rubella prevention and rubella antibody testing in fiscal year 2019, adjusting for social characteristics.

Results

Of the 1680 men aged 41–47 years who completed the survey, approximately half (51.3%) said that they had received a voucher for the rubella antibody testing and vaccination program. One-quarter (25.9%) of the respondents had used the voucher for rubella antibody testing in 2019, and 6.0% had used the voucher for rubella vaccination in fiscal year 2019. Respondents who understood the government recommendation for rubella antibody testing and vaccination for men of their generation (odds ratio [OR]: 5.50; 95% confidence interval [CI]: 4.01–7.53), those with acquaintances who had undergone rubella testing (OR: 1.39; 95% CI: 1.22–1.59), and those who knew that about their lack of opportunity for rubella vaccination (OR: 1.33; 95% CI: 1.11–1.60) tended to undergo rubella antibody testing. Receiving the most recent seasonal influenza vaccination (OR: 1.26; 95% CI: 1.10–1.43) and being able to confirm a rubella vaccination history (OR: 1.28; 95% CI: 1.13–1.46) were also associated with rubella antibody testing.

Conclusions

The ongoing Japanese test-and-vaccinate rubella program has yet to achieve its participation rate goal for 2019. Further dissemination of the government recommendation to the population is necessary, along with improvements in the accessibility of the rubella vaccination program.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-10340-8.

Post Vaccine Rubella During a Measles Outbreak: Clinical Case

Rubella is a vaccine preventable infection, and congenital rubella the most feared complication of this disease. Although young adult women are at greatest risk of post-vaccine rubella, this is also the group who potentially benefits the most from vaccine protection. Since post-vaccine disease has a mild and self-limited course, the benefit clearly exceeds the risk. During a measles outbreak in the north of Portugal, a 38-year-old woman presented with cervical posterior lymphadenopathies, fever and a maculo-papular rash one week after the administration of the measles, mumps and rubella vaccine. Measles was discarded and rubella viremia was demonstrated. Symptoms of rubella are non-specific and laboratory confirmation is essential. This is particularly relevant during a measles outbreak.

Unmasking viral sequences by metagenomic next-generation sequencing in adult human blood samples during steroid-refractory/dependent graft-versus-host disease

BACKGROUND

Viral infections are common complications following allogeneic hematopoietic stem cell transplantation (allo-HSCT). Allo-HSCT recipients with steroid-refractory/dependent graft-versus-host disease (GvHD) are highly immunosuppressed and are more vulnerable to infections with weakly pathogenic or commensal viruses. Here, twenty-five adult allo-HSCT recipients from 2016 to 2019 with acute or chronic steroid-refractory/dependent GvHD were enrolled in a prospective cohort at Geneva University Hospitals. We performed metagenomics next-generation sequencing (mNGS) analysis using a validated pipeline and de novo analysis on pooled routine plasma samples collected throughout the period of intensive steroid treatment or second-line GvHD therapy to identify weakly pathogenic, commensal, and unexpected viruses.

RESULTS

Median duration of intensive immunosuppression was 5.1 months (IQR 5.5). GvHD-related mortality rate was 36%. mNGS analysis detected viral nucleotide sequences in 24/25 patients. Sequences of ≥ 3 distinct viruses were detected in 16/25 patients; Anelloviridae (24/25) and human pegivirus-1 (9/25) were the most prevalent. In 7 patients with fatal outcomes, viral sequences not assessed by routine investigations were identified with mNGS and confirmed by RT-PCR. These cases included Usutu virus (1), rubella virus (1 vaccine strain and 1 wild-type), novel human astrovirus (HAstV) MLB2 (1), classic HAstV (1), human polyomavirus 6 and 7 (2), cutavirus (1), and bufavirus (1).

CONCLUSIONS

Clinically unrecognized viral infections were identified in 28% of highly immunocompromised allo-HSCT recipients with steroid-refractory/dependent GvHD in consecutive samples. These identified viruses have all been previously described in humans, but have poorly understood clinical significance. Rubella virus identification raises the possibility of re-emergence from past infections or vaccinations, or re-infection. Video abstract.

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

BACKGROUND

Rubella containing vaccines (RCV) prevent rubella virus infection and subsequent congenital rubella syndrome (CRS). To update the evidence on immunogenicity, duration of protection, effectiveness and safety of RCV, we conducted a systematic literature review.

METHODS

We searched EMBASE and SCOPUS, using keywords for rubella vaccine in combination with immunogenicity (seroconversion and seropositivity), duration of protection, efficacy/effectiveness, and safety. Original research papers involving at least one dose of RCV (at any age), published between 1-1-2010 and 17-5-2019 were included. Where appropriate, meta-analyses were performed. Quality of included studies was assessed using GRADE methodology.

RESULTS

We included 36 papers (32 randomized controlled trials (RCTs) and 4 observational studies) on immunogenicity (RA27/3 strain) in children and adolescent girls, 14 papers (5 RCTs and 9 observational studies) on duration of protection, one paper on vaccine effectiveness (VE) (BRDII strain), and 74 studies on safety, including three on safety in pregnancy. Meta-analysis of immunogenicity data showed 99% seroconversion (95% CI: 98-99%) after a single dose of RCV in children, independent of co-administration with other vaccines. Seroconversion after RCV1 below 9 months of age (BRDII strain, at 8 months) was 93% (95% CI: 92-95%). For duration of protection, the included studies showed a seropositivity of 88%-100% measured 1-20 years after one or two RCV doses. The single study on VE of BRDII strain, reported 100% VE after one and two doses. Among 34,332 individuals participating in the RCTs, 140 severe adverse events (SAEs) were reported as possibly related to RCV. Among the case reports on SAEs, the association with RCV was confirmed in one report (on fulminant encephalitis). Among 3,000 pregnant women who were inadvertently vaccinated, no SAEs were reported.

CONCLUSIONS

One and two doses of RCV are highly immunogenic for a long period of time, effective in preventing rubella and CRS, and safe.

Population-based study of a free rubella-specific antibody testing and immunization campaign in Chiba city in response to the 2018-2019 nationwide rubella outbreak in Japan

Japan has not been able to eliminate rubella; as a result, the large rubella epidemic has occurred. Considering the complicated history of the vaccine policy in Japan, some susceptible populations became infected with rubella, resulting in an outbreak. We conducted a large serosurveillance against rubella in Chiba city after initiating free rubella-specific antibody testing and an immunization campaign during 2018-2019. The total number of rubella specific antibody tests that was conducted in the nationwide campaign and Chiba city original campaign was 8277 and 6104, respectively. The proportion of participants with an antibody titer of ≤1:16 using the hemagglutination inhibition (HI) test was higher in those in their 20-30s. On the contrary, the proportion of participants with an antibody titer of <1:8 using the HI test was higher in men in their 40-50s. This discrepancy possibly reflects the complicated history of the vaccine policy. The number of participants in the nationwide immunization campaign in this city was 1517, whereas that in the Chiba city campaign was 3607. The Chiba city campaign was effective against women in their 20-30s (child-bearing generation); however, the nationwide campaign was not sufficiently effective against men in their 40-50s because many workers were did not visit medical facilities to receive the measles-rubella vaccine.

Factors associated with knowledges and attitudes about measles and rubella immunization in a non-health care occupational setting in Japan

INTRODUCTION

Elimination of measles and rubella has been achieved in several countries and some regions. After verified measles elimination, some countries have reported outbreaks among adults in occupational settings such as health care institution and school setting. Studies have reported that knowledge and attitude for measles and/or rubella are significantly associated with immunization uptake in adults, but few studies have been conducted in settings other than health care facilities and schools.

METHODS

We conducted a cross-sectional study among 134 office employees during a routine health checkup in June 17-20, 2014, to examine the association between willingness to receive immunization and knowledge and attitudes.

RESULTS

Approximately 75% had a protective level of antibody for measles (PA≥1:256) and rubella (HI ≥ 32 IU/mL). After adjustment for sex, age and immune status, the attitudes that immunization prevents measles (adjusted odds ratio [aOR] = 7.8, 95% confidence interval [95%CI]: 2.5-24.7) and prevents infection and transmission to others (aOR = 4.0, 95%CI: 1.4-11.4). Knowing that males are the vulnerable group for rubella infection (aOR = 5.8, 95%CI: 2.4-13.9), attitude that immunization prevents rubella infection (aOR = 7.9, 95%CI: 2.4-26.5), and prevents infection and transmit to others (aOR = 6.7, 95%CI: 2.2-20.1) were significantly associated with willingness to receive immunization after adjustment for sex, age, and immune status.

CONCLUSIONS

Studies have shown that physicians and other health care workers are important source of information for promotion of immunization. Thus, we recommend that physicians educate and promote immunization for measles and/or rubella to adults working in offices during routine health checks.

Positive predictive value of seroconversion or positive rubella IgM in diagnosis of maternal rubella infection: Seven-years review of French National Reference Laboratory for Rubella

BACKGROUND

In France, as in most developed countries, childbearing age women are routinely screened for rubella antibodies to identify and vaccinate susceptible women. Immunity to rubella is usually determined by measuring the rubella virus-specific immunoglobulin G (RV-IgG). In case of seroconversion for RV-IgG and/or positive RVIgM during pregnancy, laboratories usually send serum samples to the French National Reference Laboratory (FNRL) for Rubella in order to perform complementary investigations and confirm or exclude rubella infection during pregnancy.

OBJECTIVE

Our aim is to report results of these investigations during a seven-year period (2013-2019) and evaluate the positive predictive value (PPV) of RV-IgG seroconversion or positive RV-IgM to diagnose maternal rubella infection in France.

STUDY DESIGN

Between 2013 and 2019, 5398 serum samples collected from 4104 pregnant women, were addressed to FNRL because of RV-IgG seroconversion (N=899) or positive RV-IgM (N=3205). Additional serological tests were performed, mainly immunoblot (to look for the presence of anti-E1 protective antibody) and RV-IgG avidity (to exclude or confirm primary infection).

RESULTS

Overall, for 3724/4104 (90.8 %) women, rubella primary-infection during pregnancy was formally excluded and maternal rubella primary-infection was only confirmed in 46/4104 (1.1 %) cases.

CONCLUSION

Clinicians and biologists should be particularly aware that RV-IgG seroconversion or positive RV-IgM, in the current context of low RV circulation in France are most often not rubella primary infections. PPV of seroconversion to assess maternal rubella primary infection is as low as 0.2 % (95 % CI: 0 %; 0.5 %) and PPV of positive RV-IgM is only of 1.4 % (95 % CI: 0.99 %; 1.81 %).

Associations between markers of cellular and humoral immunity to rubella virus following a third dose of measles-mumps-rubella vaccine

INTRODUCTION

Rubella virus (RV) was eliminated in the United States in 2004, although a small portion of the population fails to develop long-term immunity against RV even after two doses of the measles-mumps-rubella (MMR) vaccine. We hypothesized that inherent biological differences in cytokine and chemokine signaling likely govern an individual's response to a third dose of the vaccine.

METHODS

Healthy young women (n = 97) were selected as study participants if they had either low or high extremes of RV-specific antibody titer after two previous doses of MMR vaccine. We measured cytokine and chemokine secretion from RV-stimulated PBMCs before and 28 days after they received a third dose of MMR vaccine and assessed correlations with humoral immune response outcomes.

RESULTS

High and low antibody vaccine responders exhibited a strong pro-inflammatory cellular response, with an underlying Th1-associated signature (IL-2, IFN-γ, MIP-1β, IP-10) and suppressed production of most Th2-associated cytokines (IL-4, IL-10, IL-13). IL-10 and IL-4 exhibited significant negative associations with neutralizing antibody titers and memory B cell ELISpot responses among low vaccine responders.

CONCLUSION

IL-4 and IL-10 signaling pathways may be potential targets for understanding and improving the immune response to rubella vaccination or for designing new vaccines that induce more durable immunity.

Durability of humoral immune responses to rubella following MMR vaccination

BACKGROUND

While administration of the measles-mumps-rubella (MMR-II®) vaccine has been effective at preventing rubella infection in the United States, the durability of humoral immunity to the rubella component of MMR vaccine has not been widely studied among older adolescents and adults.

METHODS

In this longitudinal study, we sought to assess the durability of rubella virus (RV)-specific humoral immunity in a healthy population (n = 98) of adolescents and young adults at two timepoints: ~7 and ~17 years after two doses of MMR-II® vaccination. Levels of circulating antibodies specific to RV were measured by ELISA and an immune-colorimetric neutralization assay. RV-specific memory B cell responses were also measured by ELISpot.

RESULTS

Rubella-specific IgG antibody titers, neutralizing antibody titers, and memory B cell responses declined with increasing time since vaccination; however, these decreases were relatively moderate. Memory B cell responses exhibited a greater decline in men compared to women.

CONCLUSIONS

Collectively, rubella-specific humoral immunity declines following vaccination, although subjects' antibody titers remain well above the currently recognized threshold for protective immunity. Clinical correlates of protection based on neutralizing antibody titer and memory B cell ELISpot response should be defined.

[Ocular manifestations of viral diseases]

Les infections virales peuvent toucher l’ensemble des tuniques oculaires et mettre en jeu la fonction visuelle à plus ou moins courte terme. Les kératites et kérato-uvéites liées au virus HSV-1 sont les atteintes les plus fréquentes. Les récurrences entraînent une opacification cornéenne irréversible qui en fait la première cause de cécité d’origine infectieuse dans les pays occidentaux, et justifient un traitement antiviral préventif au long cours. Le zona ophtalmique (10 à 20 % des zonas), peut s’accompagner d’atteintes oculaires sévères (kératites, kérato-uvéites), dont 30 % deviennent chroniques/récurrentes, et de douleurs post-zostériennes, redoutables dans le territoire trigéminé. Les rétinites nécrosantes liées aux herpesvirus (HSV, VZV, CMV), sont rares mais constituent des urgences fonctionnelles absolues nécessitant un traitement antiviral par voie intraveineuse et intravitréenne. Les conjonctivites à adénovirus constituent la première cause de conjonctivite infectieuse. Le plus souvent bénignes, elles sont extrêmement contagieuses et peuvent se compliquer de lésions cornéennes invalidantes persistant plusieurs mois, voire années. Certaines arboviroses s’accompagnent de manifestations oculaires inflammatoires. Dans le cas du Zika, les infections congénitales peuvent se compliquer d’atrophie maculaire et/ou optique. Les conjonctivites sont très fréquentes à la phase aiguë de la maladie à virus Ebola, dont 15 % des survivants présentent des atteintes inflammatoires chroniques sévères liées à la persistance du virus dans les tissus uvéaux. Enfin, dans le cadre de la COVID-19, les conjonctivites ne sont pas très fréquentes mais peuvent être inaugurales, voire au premier plan et sont associées à une excrétion virale lacrymale qui doit faire prendre toutes les précautions.

Rubella seroprevalence using residual samples from the South African measles surveillance program: a cross-sectional analytic study

Introduction: South Africa is yet to introduce rubella-containing vaccines (RCV) into its routine immunization schedule. Selecting the target population when introducing RCV should take into account the ages of susceptible individuals in the population. We aimed to determine the seroprevalence of antibodies to rubella and characterize immunity gaps among individuals of all ages in South Africa. Methods: We tested for rubella immunoglobulin G (IgG) antibodies with a commercial enzyme-linked immunosorbent assay. We used residual samples collected from 2016 through 2018 as part of the national measles surveillance program. We only tested samples that were negative for measles and rubella immunoglobulin M (IgM) and explored the association between rubella susceptibility (IgG negative) and predictor variables (year of sample collection, age, sex, and province of residence) using logistic regression analysis. Results: We obtained results for 6057 records. Rubella susceptibility was highest among Individuals aged zero to 11 months (81.9%), followed by children 1 to 5 years old (71.5%), 6 to 10 y old (40.9%) and 11 to 15 y old (31.25) while the smallest proportion of susceptible individuals was among those 16 to 49 y old (19.9%). Females were less likely to be susceptible to rubella compared to males (OR = 0.79 (95%CI: 0.71-0.87), P < .001) in unadjusted analysis but this effect was not observed after adjusting for age and province. In multivariable logistic regression, age (OR = 6.24 (4.52-8.63), P < .001) and province of residence (OR = 0.97 (95%CI: 0.95-0.99), P = .01) were associated with rubella susceptibility. Conclusion: In the absence of rubella vaccination in the Expanded Program on Immunization in South Africa, the bulk of individuals susceptible to rubella are children under 16 y old. About 20% of individuals 16 to 49 y old are susceptible to rubella. This susceptibility gap must be born in mind during RCV introduction.

The historical aspects of vaccination in pregnancy

As we live through the history-making pandemic of coronavirus disease 2019 (COVID-19), it is timely to consider the lessons that history has taught us about vaccine-preventable disease in pregnancy. Vaccinations have earned an established place in pregnancy care to prevent communicable disease in the mother, fetus and newborn. The improvements in maternal and perinatal outcome have been achieved through the evolution and application of new knowledge in many areas. These include recognition of the unique pathogenic consequences of diseases in pregnancy; improved understanding of the maternal immune system and its interplay with the fetus; optimizing safe vaccine development; ensuring pregnant women are included in appropriately designed trials of efficacy, and public health engagement to optimize uptake. As the world eagerly awaits an effective vaccine for COVID 19, these lessons of history help signpost the way, to ensure the potential of vaccinations to reduce morbidity for pregnant women and their newborns is fully realized.

Rubella outbreak among workers in three small- and medium-size business establishments associated with imported genotype 1E rubella virus-Shizuoka, Japan, 2015

On 12 February 2015, a local health department (LHD) in Shizuoka prefecture identified two reported rubella cases in its jurisdiction as employees of the same company. As other employees at the company resided both inside and outside of the health department's jurisdiction, it began collaborating with two additional LHDs and the National Institute of Infectious Diseases to investigate and respond to the outbreak, which subsequently identified cases in two additional companies. We obtained epidemiological, clinical, and outbreak response information from the national epidemiological surveillance of infectious disease system's database, the local health departments, and the associated companies. One specimen for genetic sequencing was collected from each of the three companies. The outbreak included a total of twenty-five cases, with seventeen confirmed and eight probable cases from three companies. Among them, 24 (96%) were male, 22 (88%) were employees of one company (Company X), and none had rubella vaccination history. The median age was 45 years (interquartile range: 40-51). Epidemiological information did not reveal the source of infection nor transmission route. All rubella viruses sequenced from the three specimens were classified into genotype 1E. The nucleotide sequences in the 739 bp-window region were completely identical in two specimens, with only one nucleotide difference in the third specimen. According to phylogenetic analysis, these strains were closely related to the Southeast and East Asian lineage. This rubella outbreak at three companies, ranging in size from small- to medium-size, in Japan occurred among unvaccinated employees aged at least 30 years, most of whom were male. Virologic analyses suggest all cases were infected with the same viral strain imported from Southeast Asia. Similar to these companies, most employees at small- and medium-size businesses in Japan are males with no vaccination history for rubella, which poses a serious risk for associated cases of congenital rubella syndrome (CRS).