Seroprevalence of rubella antibodies and determinants of susceptibility to rubella in a cohort of pregnant women in Canada, 2008–2011

Long term control of rubella and congenital rubella syndrome relies on high population-level immunity against rubella, particularly among women of childbearing age. In Canada, all pregnant women should be screened so that susceptible new mothers can be offered vaccination for rubella before discharge. This study was undertaken to estimate rubella susceptibility in a cohort of pregnant women in Canada and to identify associated socio-economic and demographic factors. Biobanked plasma samples were obtained from the Maternal-Infant Research on Environmental Chemicals (MIREC) study, in which pregnant women were recruited between 2008 and 2011. Socio-demographic characteristics and obstetric histories were collected. Second trimester plasma samples (n = 1,752) were tested for rubella-specific IgG using an in-house enzyme-linked immunosorbent assay. The percentage of women with IgG titers <5 IU/mL, 5–10 IU/mL, and ≥10 IU/mL were 2.3%, 10.1%, and 87.6%, respectively. Rates of seronegativity, defined as <5 IU/mL, were 3.1% in women who had no previous live birth and 1.6% in women who had given birth previously. Among the latter group, seronegativity was higher in women with high school education or less (adjusted OR (aOR) 5.93, 95% CI 2.08–16.96) or with a college or trade school diploma (aOR 3.82, 95% CI 1.45–10.12), compared to university graduates, and those born outside Canada (aOR 2.60, 95% CI 1.07–6.31). In conclusion, a large majority of pregnant women were found to be immune to rubella. Further research is needed to understand inequalities in vaccine uptake or access, and more effort is needed to promote catch-up measles-mumps-rubella vaccination among socioeconomically disadvantaged and immigrant women of childbearing age.     

Safety profile of rubella vaccine administered to pregnant women: A systematic review of pregnancy related adverse events following immunisation,including congenital rubella syndrome and congenital rubella infection in the foetus or infant

BackgroundData on the safety of inadvertent rubella vaccination in pregnancy is important for rubella vaccination programs aimed at preventing congenital rubella syndrome.MethodsThe association between monovalent rubella or combination vaccinations in or shortly before pregnancy and potential harm to the foetus was examined by conducting a systematic review and meta-analysis using fixed effect methods and simulation.ResultsFour cohort studies of inadvertently vaccinated and unvaccinated women were found, 15 cohorts of pregnant women who were rubella susceptible at time of inadvertent vaccination and 9 cohort studies with no information on susceptibility and case series. No case of vaccine associated congenital rubella syndrome (CRS) was identified. Cohort studies with an unvaccinated comparison group were limited in number and size, and based on these only a theoretical additional risk of 6 or more cases of CRS per 1000 vaccinated women (0% observed, upper 95% CI 0.6%) could be excluded. Based on cohorts of vaccinated rubella susceptible pregnant women a maximum theoretical risk of 1 CRS case in 1008 vaccinated women (0% observed, upper 95% CI 0.099%) was estimated. Asymptomatic rubella vaccine virus infection of the neonate was also noted (fixed effects estimate of risk overall 1.74%, 95% CI 1.21, 2.28).ConclusionThere is no evidence that CRS is caused by rubella-containing vaccines but transplacental vaccine virus infection can occur. CRS is effectively prevented by vaccination, thus the risk/benefit balance is unequivocally in favour of vaccination. The data confirm previous recommendations that inadvertent vaccination during pregnancy is not an indication for termination of pregnancy.     

Increase of immunity to rubella and interruption of rubella transmission in Gipuzkoa (Basque Country, Spain) after an enhanced vaccination programme

In Spain, vaccination against rubella was initiated in schoolgirls in the mid-1970s. In Gipuzkoa, subsequent extensions to the vaccination schedule culminated in 1992 with the introduction of the two-dose measles, mumps and rubella vaccine in children and adolescents of both sexes. Moreover, in 1985 a programme for the identification and vaccination of non-immune parturient women was implemented in the region's main hospital. The prevalence of rubella-susceptible parturient women decreased from 3.7 % at the beginning of the study to < 1.5 % by 1992. Despite this overall decrease, 4.8 % of adolescent parturients were susceptible to rubella during 2001--2002. From 1984, the number of reported cases of rubella (children and adults) progressively decreased until 1997, after which there have been no cases of indigenous rubella. There have been no cases of reported congenital rubella since 1984. These results indicate that the vaccine policy carried out in this geographical area has been effective in achieving considerable progress towards rubella elimination.     

Knowledge,attitudes, and practices regarding seasonal influenza vaccination during pregnancy in Costa Rica: A mixed-methods study

BackgroundInfluenza increases stillbirth risk, morbidity and mortality in pregnant women. Vaccination protects pregnant women against severe disease and indirectly protects their infants, but coverage among pregnant women remains low worldwide. We aimed to describe knowledge, attitudes, and practices (KAP) regarding seasonal influenza vaccination among postpartum women and prenatal care physicians in Costa Rica.MethodsWe conducted cross-sectional KAP surveys to women one to three days after childbirth at Costa Rican Social Security Fund maternity hospitals, and obstetricians and general practitioners who provided prenatal care in 2017. Principal components analysis, multiple imputation, and logistic regression were used to examine associations between influenza vaccination and demographics, prenatal care, and sources of information—separately for postpartum women and physicians. We also held two focus groups of six healthcare workers each to further describe vaccination KAP.ResultsWe surveyed 642 postpartum women and 146 physicians in maternity hospitals in five Costa Rican provinces of whom 85.5 % (95 % CI: 82.6 %-88.0 %) and 57.9 % (95 % CI: 49.6 %-65.7 %) were vaccinated for influenza, respectively. Factors associated with influenza vaccination for postpartum women included tetanus vaccination (aOR: 3.62, 95 % CI: 1.89–6.92); received vaccination recommendations from clinicians during prenatal check-ups (aOR: 3.39, 95 % CI: 2.06–5.59); had other children in household vaccinated for influenza (aOR: 2.25, 95 % CI: 1.08–4.68); and secondary/university education (aOR: 0.15–0.31) with no formal education as reference. For postpartum women, reasons for vaccination were perceived benefits for mother and infant, whereas not being offered vaccines was most cited for non-vaccination. Most prenatal care physicians recommended influenza vaccines during prenatal check-ups but believed vaccination causes flu-like symptoms.ConclusionVaccination campaigns and provisions of free vaccines effectively increased knowledge and coverage among women in Costa Rica. To improve access, women should be offered vaccines during prenatal care appointments. Educating healthcare workers about vaccine benefits for themselves and patients is needed to mitigate safety concerns.     

Risk of perinatal transmission of rubella and parvovirus B19 in Jordanian pregnant women

The seroprevalence and the risk of perinatal transmission of rubella virus (RV) and human parvovirus B19 were assessed in 439 Jordanian pregnant women. Seroprevalence data indicate that 43.7%, 48.7% and 19% of women are susceptible to RV, parvovirus B19 infections and both, respectively. A total of 12.2% and 20.2% of RV susceptible women are at the first and second trimester of gestation, respectively. They are at risk of bearing infants with congenital rubella syndrome (CRS). However, 15% and 23% of parvovirus B19 susceptible women are at the first and second trimester of gestation, respectively. They are at risk of fetal loss or hydrops fetalis. Prenatal screening for these viruses, postpartum MMR vaccination and parvovirus B19 passive immunization are recommended.     

2005年山东省部分孕期妇女风疹易感性调查

[目的]了解山东省孕期妇女风疹易感性水平,为调整风疹疫苗免疫策略提供依据。[方法]2005年,采集不同地区到医院准备分娩的20~40岁孕妇血清,采用间接酶联免疫吸附定量法检测风疹IgG抗体。[结果]检测标本3 788份,风疹抗体阳性(>20 IU/ml)的2 942人,阴性(<10 IU/ml)的314人,临界值(10~20 IU/ml)的532人,易感(临界值和阴性者)合计846人,易感率为22.33%。几何平均抗体含量(CMT)为34.93 IU/ml。不同地区风疹易感率和CMT的差异均有统计学意义(P<0.01);风疹易感率有随年龄增长而增高的趋势(P<0.01)。[结论]山东省近1/4的孕妇为风疹的易感者,有必要对育龄期妇女开展风疹疫苗接种。     

Reasons for rubella susceptibility among pregnant women in west Lambeth.

One hundred and thirty-three pregnant women who delivered at St Thomas' Hospital, in 1990 were noted to require rubella vaccination post partum. Fifty-three (39%) had completed a telephone questionnaire in order to determine reasons for susceptibility to rubella. Laboratory reports confirmed that 92 women were rubella seronegative and 27 had low levels of antibody. Of the 53 women interviewed, 25 gave a history of one or more rubella immunizations, 20 had no history of immunization and vaccination history was unknown for eight. Eleven of the 20 unvaccinated women had not been at school in the UK between 11 and 14 years of age. Eighty-seven per cent of the patients' general practitioners had no knowledge of their patients' rubella antibody status. Ninety-four per cent of the 133 women received rubella vaccine post partum. The Department of Health guidelines should be more vigorously implemented in order to identify and immunize remaining rubella susceptible women of child-bearing age. Susceptibility among women with a history of rubella immunization suggests that the seroconversion rate following rubella immunization in clinical practice may be lower than in vaccine trials.     

Comparison of rubella seroepidemiology in 17 countries: progress towards international disease control targets

OBJECTIVE: To standardize serological surveillance to compare rubella susceptibility in Australia and 16 European countries, and measure progress towards international disease-control targets. METHODS: Between 1996 and 2004, representative serum banks were established in 17 countries by collecting residual sera or community sampling. Serum banks were tested in each country and assay results were standardized. With a questionnaire, we collected information on current and past rubella vaccination programmes in each country. The percentage of seronegative (< 4 IU/ml) children (2-14 years of age) was used to evaluate rubella susceptibility, and countries were classified by seronegativity as group I (< 5%), group II (5-10%) or group III (> 10%). The proportion of women of childbearing age without rubella protection (< or = 10 IU/ml) was calculated and compared with WHO targets of < 5%. FINDINGS: Only Romania had no rubella immunization programme at the time of the survey; the remaining countries had a two-dose childhood schedule using the measles, mumps and rubella (MMR) vaccine. The percentage of susceptible children defined five countries as group I, seven as group II and four as group III. Women of childbearing age without rubella protection were < 5% in only five countries. CONCLUSION: Despite the low reported incidence in many countries, strengthening the coverage of the routine two-dose of MMR vaccine among children is needed, especially in group III countries. Catch-up campaigns in older age groups and selective targeting of older females are needed in many countries to ensure necessary levels of protective immunity among women of childbearing age.     

Seroprevalence of rubella in the cord blood of pregnant women and congenital rubella incidence in Nha Trang,Vietnam

To investigate susceptibility to and factors associated with rubella infection among pregnant mothers and to estimate the burden of congenital rubella infection (CRI) in Vietnam where rubella-containing vaccine (RCV) is not included in the routine immunization program, we conducted a prospective cohort study in Nha Trang, Vietnam between 2009 and 2010. Rubella-specific immunoglobulin-M and immunoglobulin-G were investigated in cord blood samples by enzyme immunoassay. Corresponding clinical–epidemiological data were analyzed and the national congenital rubella syndrome (CRS) incidence was estimated using modeling. We enrolled 1988 pairs of mothers aged 17–45 years and their newborn babies. No mothers had received RCV. Multivariate analysis revealed that mothers aged 17–24 (aOR 2.5, 95% CI: 1.7–3.8) or 25–34 (1.4, 1.0–2.1) years were more likely to be susceptible than those aged 35–45 years. Overall 28.9% (574/1988, 95% CI: 26.9–30.9%) of mothers were seronegative. The CRI rate was 151 (95% CI: 0–322) per 100,000 live births. Modeling estimated that 3788 babies (95% CI: 3283–4143) were born with CRS annually in Vietnam with an overall CRS incidence of 234 (95% CI: 207–262) cases per 100,000 live births. A substantial proportion of women of childbearing age (WCBA) are at risk of rubella infection during pregnancy and this can result in a high frequency of miscarriage or burden of CRS across Vietnam. Prompt introduction of RCV into national immunization program with catch-up vaccination to children and WCBA will reduce CRI in Vietnam.     

Comparing the rubella seronegativity in pregnant women who received one dose of rubella vaccine at different ages in Taiwan

IntroductionVaccination is the best strategy to prevent rubella and congenital rubella. The aim of our study was to assess the immunity to rubella and determine rubella virus antibody titers in pregnant women who were offered a single dose of rubella vaccine at different ages of their lives.MethodsA total 15,067 rubella IgG antibody test results for Taiwanese pregnant women who received routine prenatal checkup at Fooyin University Hospital from 1999 to 2014 were analyzed in this study. The women were divided into five birth cohorts in order to compare their rubella seronegativities and antibody titers according to the different period of rubella vaccination policy in Taiwan.ResultsThe total rubella seronegativity rate was 11.2% (95% CI: 10.7–11.7%) and the mean rubella antibody titers was 51.0 IU/mL (SD = 54.7 IU/mL). The junior school cohort has the lowest rubella seronegativity of 7.6% (95% CI: 6.9–8.2%). The seronegativities were significantly high in the preschool cohort and in the 15-month-old cohort, 14.9% (95% CI: 13.2–16.6%) and 14.8% (95% CI: 11.5–18.1%), respectively. The OR values were 2.1 (95% CI: 1.8–2.5, p < 0.001) in the preschool cohort and 2.2 (95% CI: 1.6–2.8, p < 0.001) in the 15-month-old cohort, respectively, against the junior school cohort. Women in the 15-month-old cohort have lowest average rubella IgG titer, 25.4 IU/mL.ConclusionThe total rubella seronegativity rate was 11.2% in all native pregnant women. Women who received one dose rubella vaccine at preschool and 15-month-old have highest seronegativities. The 15-month-old cohort has the lowest average rubella IgG titer. We recommend a revised catch-up immunization policy to women who received one dose rubella vaccine at a younger age.     

Rubella seroprofile of the Italian population: an 8-year comparison

The objective of this study is to evaluate how increasing MMR infant vaccination coverage in recent years has modified the epidemiology of rubella in Italy. A cross-sectional population-based seroprevalence study of rubella antibodies was conducted on 3094 sera, in 2004, and results were compared with data obtained by the same method in 1996. The overall proportion of rubella-seropositive individuals was found to be significantly higher in 2004 with respect to 1996 (84.6% vs. 77.4%). However, an increase in seropositivity was observed only in the 1-19 years age groups. Recent increases in childhood MMR vaccination coverage, therefore, have not had an impact on seroprevalence in women of childbearing age, over 5% of whom remain susceptible to rubella. Preconception screening and postpartum vaccination of susceptible women are fundamental if the WHO target of less than one case of congenital rubella syndrome per 100,000 live births is to be attained.     

Seroepidemiological profile of pregnant women after inadvertent rubella vaccination in the state of Rio de Janeiro, Brazil, 2001-2002.

OBJECTIVES: To analyze postvaccination serological status in pregnant women inadvertently vaccinated against rubella in the state of Rio de Janeiro, Brazil. METHODS: This was a cross-sectional study of pregnant women 15 to 29 years old, vaccinated against rubella and measles from November 2001 to March 2002, who were unaware of their pregnancy at the time of vaccination or who became pregnant within 30 days thereafter. They were tested for rubella-specific immunoglobulin M (IgM) and G (IgG) and classified as immune (IgM-negative, IgG-positive, tested within 30 days after vaccination), susceptible (IgM-positive after vaccination) or indeterminate (IgM-negative, IgG-positive, vaccination-serological testing interval greater than 30 days). RESULTS: Of 2 292 women, 288 (12.6%) were susceptible, 316 (13.8%) immune, 1 576 (68.8%) indeterminate, 8 (0.3%) ineligible, and 104 (4.5%) lost to follow-up. IgM seropositivity by vaccination-serological testing interval was 16.1% (相似文献   

A rubella serosurvey in postpartum women in the three regions of Peru.

OBJECTIVE: To determine the proportion of postpartum women aged 15-49 in Peru who are susceptible to rubella, in order to help address strategies to eliminate rubella and to prevent congenital rubella syndrome (CRS) in the country. METHODS: A cross-sectional survey was conducted during March and April 2003 in six main regional hospitals, in the three geographic regions (coast, mountain, and jungle) of Peru. For the postpartum women who provided written informed consent, a questionnaire was administered and a blood specimen was collected. Sera were tested for rubella immunoglobulin G (IgG) antibody, using a commercial enzyme-linked immunosorbent serologic assay (ELISA) kit. Univariate, bivariate, and multivariate analyses were carried out to assess risk factors for susceptibility. RESULTS: In total, 1 236 postpartum women were enrolled. The overall proportion of IgG-antibody negative women was 12.8% (95% confidence interval (CI): 10.9%-14.6%). Bivariate analysis found the following variables associated with susceptibility: living in the jungle region (odds ratio (OR) = 1.65; 95% CI: 1.13-2.42); age < 19 years (OR = 2.02; 95% CI: 1.35-3.03); being a housewife (OR = 1.69; 95% CI: 1.12-2.55); and having < or = 11 years of education (OR = 2.12; 95% CI :1.20-3.75). Multivariate analysis found the following variables were associated with susceptibility: living in the jungle region (OR = 1.67; 95% CI: 1.13-2.46); age < 19 years (OR = 1.62; 95% CI: 1.07-2.47); having < 4 children born alive (OR = 1.85; 95% CI: 1.00-3.40); and having < or = 11 years of education (OR = 2.07; 95% CI: 1.16-3.71). CONCLUSIONS: The proportion of postpartum women at the study sites who were found to be susceptible to rubella was 12.8%, placing Peru among the countries facing a moderate level of risk for the occurrence of CRS cases. The findings suggest the need to also provide the rubella vaccine to other population groups, especially women of childbearing age.     

Measles–mumps–rubella vaccination and respiratory syncytial virus-associated hospital contact

BackgroundThe live measles vaccine has been associated with lower non-measles mortality and admissions in low-income countries. The live measles–mumps–rubella vaccine has also been associated with lower rate of admissions with any type of infection in Danish children; the association was strongest for admissions with lower respiratory infections.ObjectiveTo examine whether measles, mumps, and rubella (MMR) vaccination was associated with reduced rate of hospital contact related to respiratory syncytial virus (RSV) in a high-income country.MethodsNationwide cohort study of laboratory-confirmed RSV hospital contacts at age 14–23 months in all children born in Denmark 1997–2002 who had already received the vaccine against diphtheria, tetanus, pertussis (acellular), polio, and Haemophilus influenzae type b (DTaP-IPV-Hib) at the recommended ages of 3, 5, and 12 months.ResultsThe study included 888 RSV hospital contacts in 128,588 person years of follow up (rate 6.8/1000 person years). Having MMR as the most recent vaccine was associated with a reduced rate of RSV hospital contacts compared with having DTaP-IPV-Hib as the most recent vaccine (Incidence rate ratio (IRR), 0.75; 95% confidence interval (CI), 0.63–0.89). After adjustment for potential confounders including exact age in days the IRR was 0.78 (95% CI, 0.66–0.93). The adjusted IRR was 0.74 (95% CI, 0.60–0.92) in males and 0.84 (95% CI, 0.66–1.06) in females (P Interaction, 0.42). There was no association in the first month after MMR vaccination (adjusted IRR, 0.97; 95% CI, 0.76–1.24) but the adjusted IRR was 0.70 (95% CI, 0.58–0.85) from one month after MMR vaccination.ConclusionsMMR vaccination was associated with reduced rate of hospital contacts related to laboratory-confirmed RSV infection. Further research on the association between MMR vaccination and other unrelated pathogens are warranted.     

Rubella susceptibility among pregnant women in North London, 1996-1999

BACKGROUND: Rubella infection and congenital rubella are currently rare in the United Kingdom, although sporadic cases occur, often associated with travel abroad. Uptake of the combined measles, mumps and rubella (MMR) vaccine has declined in recent years, and there is a danger that rubella infection could start to circulate again, with serious implications for susceptible pregnant women. This could be a particular problem in communities where there are relatively high rubella susceptibility rates because of either poor vaccine uptake over several years or the presence of significant numbers of recent immigrants from countries without routine rubella vaccination programmes. METHODS: Routinely collected data on rubella susceptibility in pregnant women in the former North West Thames region were available for 1996-1999. Associations between year of delivery, maternal age, parity and ethnic group, and rubella susceptibility were explored. RESULTS: Overall rubella susceptibility declined significantly from 2.6 per cent to 2.4 per cent between 1996 and 1999. Whereas less than 2 per cent of British-born women were susceptible, overall susceptibility for other women was about 5 per cent. African and Asian women had particularly high susceptibility rates, and patterns of susceptibility by age and parity varied across ethnic groups. CONCLUSIONS: If rubella were to re-establish itself in the United Kingdom, women who had come to Britain in later childhood or adult life would be at higher risk of acquiring infection in pregnancy than indigenous women. Appropriate local and national strategies should be devised to ensure that all such women are offered rubella vaccination at the earliest opportunity.     

A resurgence of congenital rubella in Australia?

Two infants with congenital rubella defects (congenital rubella syndrome) have been reported from Queensland in 2003, after an increase in rubella in that State in 2001-2002. The national Measles Control Campaign in 1998 aimed to give measles-mumps-rubella (MMR) vaccine to all unvaccinated preschoolers and a second dose to primary schoolchildren. Following the Campaign no children with congenital rubella defects were born to Australian-born mothers during the five years 1998 to 2002, according to reports to the Australian Paediatric Surveillance Unit. However, three imported cases occurred. Broad immunisation coverage and detection and vaccination of susceptible women of child-bearing age before they become pregnant are necessary to prevent further cases.     

Effectiveness of Rubella vaccine in a rubella outbreak in Guangzhou city,China, 2014

BackgroundWHO recommends the use of rubella-containing vaccine (RCVs) to prevent rubella and congenital rubella syndrome (CRS). Most licensed rubella vaccines in use globally are based on RA27/3 strains and have estimated vaccine effectiveness (VE) rates of 95–100%. In contrast, China uses a BRD-II strain-based rubella vaccine. Few field studies have been conducted that estimate VE of China's RCV. On March 17, 2014, a rubella outbreak was reported in a middle school in Guangzhou city, China. We conducted an investigation to understand reasons for the outbreak, and we used that investigation to estimate vaccine effectiveness of China's rubella vaccine.MethodsTo identify cases, investigators reviewed records kept by the school doctor and absentee records kept by teachers. Self-administered questionnaires were sent to parents of all students to collect information about the students’ symptoms, the results of any physician consultation, and disease history. We obtained demographic information and illness information for all students in the school; vaccination status was determined by inspection of official, parent-held vaccination records. A retrospective cohort study was conducted in 13 classes that had secondary cases of rubella. Using the secondary attack rates, we evaluated VE by the number of RCV doses received and age at vaccination.ResultsDuring the period February 17–May 23, 2014, 162 students (50 suspected cases, 88 probable cases, 24 confirmed cases) were diagnosed with rubella, yielding an overall attack rate of 10% (162/1621). Cases occurred in 27 classes (73%) of 37 classrooms. Secondary cases occurred in 13 classes (35%) of 37 classrooms. A total of 1130 students (69.7%) have vaccination certificates; 419 (37%) students were record-confirmed to have received RCV. For those vaccinated using BRD-II strain vaccine, vaccine effectiveness (VE) was 94% (95%CI: 75–98). VE for measles, mumps, and rubella (MMR) vaccine which is based on either BRD-II or RA27/3 strain was 89% (95%CI: 56–97). VE of a single dose of domestic monovalent rubella vaccine that used BRD-II strain vaccine was 93% (95%CI: 73–98). VE for those who received the vaccine between 1 and 2 years of age was 95% (95% CI: 67–99) while the VE was 100% for those vaccinated after 2 years of age. VE among those who received RCV <12 years ago was 100% while VE among those who received RCV ≥12 years ago was 92% (95%CI: 70–98).ConclusionsThe rubella vaccines used in China that are based on the BRD-II rubella vaccine strain have VE of 94%, which is similar to the more commonly used RA27/3-based RCVs. Low vaccination coverage contributed to this outbreak; early reporting of an outbreak is necessary for effective outbreak response immunization.     

4~6岁儿童接种麻疹-流行性腮腺炎-风疹联合减毒活疫苗加强免疫的免疫原性与安全性研究

目的:探讨4~6岁儿童接种麻疹-流行性腮腺炎-风疹联合减毒活疫苗（MMR）后的加强免疫原性与安全性。方法:分别在山西省、内蒙古自治区以及北京市招募曾有8月龄和18月龄接种过1剂麻疹-风疹联合减毒活疫苗和MMR疫苗免疫史的4~6岁儿童作为研究对象,分为4、5、6岁组,进行MMR疫苗加强免疫研究。接种MMR疫苗前与接种后3...     

Seroprevalence of Antibodies to Measles, Mumps, and Rubella among Thai Population: Evaluation of Measles/MMR Immunization Programme

Stored serum specimens, from four regions of Thailand, of healthy children attending well baby clinics and of healthy people with acute illnesses visiting outpatient clinics were randomly sampled and tested for IgG antibody to measles, mumps, and rubella (MMR). The immunity patterns of rubella and mumps fitted well with the history of rubella and MMR vaccination, seroprotective rates being over 85% among those aged over seven years. A high proportion of younger children acquired the infection before the age of vaccination. MMR vaccination should preferably be given to children at an earlier age. For measles, 73% seroprotective rates among children, aged 8-14 years, who should have received two doses of measles/MMR vaccine, were lower than expected. This finding was consistent with the age-group reported in outbreaks of measles in Thailand. The apparent ineffectiveness (in relation to measles) of MMR immunization of 1^st grade students warrants further studies.Key words: Antibodies, Immunization, Measles, Measles vaccine, Mumps, MMR vaccine, Rubella, Seroepidemiologic studies, Seroprevalence, Vaccination, Thailand