Control of rubella and congenital rubella syndrome (CRS) in developing countries, Part 2: Vaccination against rubella.

In 1995-96 we conducted a review of rubella immunization strategies. Worldwide, 78 countries (more than one-third) reported a national policy of using rubella vaccine. This was closely related to country economic status. Based on the United Nations country classification, rubella vaccine is used in 92% of industrialized countries, 36% of those with economies-in-transition, and 28% of developing countries. Cases of congenital rubella syndrome (CRS) may be prevented as follows: by providing direct protection to women and/or schoolgirls (a selective vaccination strategy); by vaccinating boys and girls to provide indirect protection by reducing the transmission of rubella virus (a childhood vaccination strategy); or by a combination of these approaches (a combined strategy). A combined strategy was most commonly reported (60% of countries); seven countries (9%) reported a selective strategy; and 24 countries (31%) reported only childhood immunization. Experience has shown that it is essential to include vaccination of women of childbearing age in any rubella control strategy. Childhood vaccination alone may pose a risk of an increase in CRS cases. Although many countries have introduced rubella vaccine, few report any data on the impact of vaccination. Countries using rubella vaccine need to establish surveillance for rubella and CRS and monitor coverage in each of the target groups.     

Development of the Rubella Vaccine and Vaccination Strategy in Japan

The development of the rubella vaccine and vaccination strategy in Japan was unique. Five rubella vaccines used in Japan were licensed, and the rubella vaccination program to schoolgirls was started in 1977. The measles-mumps-rubella vaccination to children, which was started in 1989, was terminated in 1993 due to the adverse effect of aseptic meningitis. In 1994, rubella vaccination to children, using the monovalent rubella vaccine, was restarted. Then, a new vaccination program, vaccinating twice by using the combined measles and rubella vaccine, was started in 2006. The increase in the rate of vaccination leads us to hope for the “Elimination of Rubella and Congenital Rubella Syndrome in 2012”.     

Prevalence of antibodies against rubella virus in The Netherlands 9 years after changing from selective to mass vaccination

A two-dose mass vaccination programme with a combined vaccine against measles, mumps and rubella (MMR) was adopted in the Netherlands in 1987, replacing the selective schoolgirl vaccination strategy introduced in 1974. To obtain insight into the effect of mass vaccination and the population's immunity, the antibody levels against rubella were studied in the general Dutch population and in religious groups refusing vaccination. In the national sample, we observed a high prevalence (96.5%) for rubella antibodies in vaccinated cohorts as well as in the older unvaccinated cohorts. No indications of rapidly waning immunity after vaccination were found. There are indications of low virus circulation in the last few years. The very high seroprevalence in women at childbearing age is consistent with the few reported cases of congenital rubella syndrome (CRS) at present. However, individuals in the age group of 1-9 years who are not vaccinated for religious or other reasons have a considerably lower seroprevalence and thus there is a potential risk of a CRS outbreak in the future.     

Seroprevalence of rubella in school girls and pregnant women

Many studies have been assigned to investigate the surveillance of congenital rubella syndrome, acquired rubella and seroprevalence in different countries to determine the new vaccination program and national vaccination schedules. Seroprevalence of rubella in Turkey is still insufficient and national immunization schedules do not include routine rubella vaccination. In this study we aimed to investigate the seroprevalence of rubella at child bearing age in an unvaccinated population in Adana, southern Turkey, to help determine whether routine rubella vaccination is necessary, if so when it should be administered. Ninety-four school girls aged 12–18 years living in Adana were selected for the study and stratified according to the socioeconomic status of their parents and evaluated for rubella antibodies. One hundred pregnant women aged 18–25 years and 100 pregnant women aged 26–35 years were sampled rubella antibodies. Rubella specific IgG antibody was measured qualitatively and quantitatively by using microparticule enzyme immune assay technology. Rubella specific IgG antibody was positive in 87–94 school girls (92.5%). The geometric mean rubella specific IgG antibody value was found be 148.14 IU/ml. No correlation was found between socioeconomic status and rubella seropositivity (p = 0.6521). In all pregnant women rubella specific IgG antibody was found to be positive. In conclusion rubella vaccination should be considered carefully in developing countries. Because of the high seropositivity to rubella in our region we do not recommend rubella vaccination in early childhood. Yet this is a preliminary study and further studies with larger population size are needed to determine the national immunization policy for rubella.     

Policies for immunization against rubella in European countries

In 1986 a survey on immunization policies against rubella was conducted in 17 European countries. A questionnaire was sent to each Ministry of Health and selected practitioners, requesting information on official policy for vaccination against rubella, level of policy decision, immunization strategy, target groups, current recommendations for vaccination, measures taken to facilitate vaccine uptake, vaccine strains used and legislation concerning abortion.A policy for the prevention of congenital rubella is explicitly defined in 16 countries (in 12 at a national level, in 3 at a regional level and in one at both levels). In Greece only, no official policy has been defined, although the practice is to vaccinate infants over 15 months of age and girls by 9–11 years of age. There are 3 countries maintaining the selective strategy of vaccinating teenage girls, but in 8 countries this strategy changed to a mass vaccination of young infants. In 5 other countries an approach combining both mass immunization and selective vaccination is adopted. This situation of different strategies between countries in Europe could have a deleterious effect for young migrants or travelling pregnant women and could reduce the effectiveness of programmes for prevention of congenital rubella syndrome. Harmonization of immunization policies and of recommendations for vaccine administration is advisable. The mass vaccination of all young children combined with systematic revaccination either of all children or of teenage girls is probably the most effective approach for elimination of congenital rubella syndrome in Europe.Corresponding author.     

2012年北京市西城区健康人群风疹抗体水平调查及疫苗免疫效果分析

目的 评估2012年北京市西城区健康人群风疹抗体水平及疫苗的免疫效果,为预防控制风疹及完善疫苗免疫策略提供科学依据。 方法 2012年随机抽取西城区10个居委会为调查点,选择在当地连续居住6个月以上的本市和外省健康人群,采集血清标本共220份,采用酶联免疫吸附试验(ELISA)测定风疹IgG抗体,同时调查免疫史、患病史及人口学特征。 结果 风疹IgG抗体阳性率为90.00%,抗体几何平均浓度(GMC)为40.78 IU/ml,不同性别、不同户籍风疹抗体阳性率和GMC比较差异无统计学意义(均P>0.05)。有免疫史人群风疹抗体阳性率和GMC均高于无免疫史人群(均P<0.001)。接种风疹疫苗5年后,抗体阳性率仍维持在较高水平。不同年龄组人群中,风疹抗体阳性率和GMC比较差异有统计学意义(P<0.05)。1.5~岁,6~岁,15~岁及35~岁组,风疹抗体阳性率在95.45%~100%之间。25~34岁年龄组风疹抗体阳性率为88.64%,低于其他年龄组(P<0.05)。风疹抗体GMC随年龄增长和免疫后时间延长而逐渐下降。 结论 风疹疫苗的免疫效果持久。2012年北京市西城区健康人群风疹抗体保持在较高水平,预测近期不会发生风疹暴发流行。应继续做好疫情监测,当出现风疹流行迹象时,建议对育龄妇女开展风疹疫苗加强免疫,预防先天性风疹综合征的发生。     

上海市麻疹、流行性腮腺炎、风疹抗体水平调查分析

[目的 ]　了解本市健康人群麻疹、腮腺炎、风疹的抗体水平。　 [方法 ]　采集 0～ 5 0岁健康人群血标本 5 43份 ,检测麻疹、腮腺炎、风疹抗体。　 [结果 ]　小于 8月龄组麻疹抗体GMT最低 ,接种麻疹疫苗后抗体GMT显著升高 (P<0 .0 0 1) ;小于 8月龄组及 8月龄组风疹抗体水平最低 ,1岁接种疫苗后风疹抗体显著升高 (P <0 .0 0 1) ,但随着年龄的增长抗体水平有所下降 ,抗体阳性率维持在 85 %以上 ;小于 8月龄组及 8月龄组流行性腮腺炎抗体水平最低 ,1岁以上各年龄组抗体水平显著上升 (P <0 .0 0 1)。　 [结论 ]　上海市现阶段实行麻疹疫苗、MMR疫苗的接种程序比较合理和有效 ,但应该进一步开展上海市育龄期妇女风疹抗体水平调查和MMR疫苗免疫持久性观察 ,研究预防未及龄儿童麻疹疫苗免疫策略、育龄期妇女接种风疹疫苗免疫策略 ,预防先天性风疹综合征     

A systematic review of rubella vaccination strategies implemented in the Americas: impact on the incidence and seroprevalence rates of rubella and congenital rubella syndrome

Objective

To evaluate the impact of rubella vaccination strategies on the rates of acquired rubella and congenital rubella syndrome in the Americas.

Methods

We conducted a systematic review of the literature (MEDLINE, PubMed, EMBASE, Cochrane Library, Artemisa Database, LILACS Database, Evidence Portal, VHL-PAHO Portal, Scielo, and Grey-Literature sources) that was published from 1969–2010. We included studies on rubella incidence and seroprevalence rates that were associated with rubella vaccination. The quality of the studies was evaluated according to international guidelines.

Results

A total of 14 studies were identified: 2 clinical trials, 2 cohort studies, 3 transversal studies, 5 ecological studies, and 2 mathematical models. Childhood vaccination reduced the incidence of rubella by 23.6% to 99.6%, increased the occurrence of epidemic cycles in Argentina and in the United States, and shifted the illness to susceptible adults. Vaccination strategies that focused on women and children in Brazil were associated with a 5.5-fold greater incidence of rubella in men leading to new outbreaks and CRS. A combined vaccination strategy with a universal approach that included routine vaccination for boys, girls, women, and men in Mexico and in Costa Rica reduced the incidence of rubella by more than 98% and led to absence of CRS since 2008. A medium and a low risk of bias were found in 3 and 4 articles, respectively.

Conclusion

The results of this review demonstrate that the combined vaccination strategy with a universal approach was the most effective strategy as evidenced by a drastic reduction in the number of cases and the interruption of endemic transmission of rubella in the Americas.     

Rötelsituation in Deutschland Ergebnisse der seroepidemiologischen Überwachung von 1990 bis 1998

The present situation regarding rubella is reflected in seroprevalence studies performed between 1990 and 1998. By selective immunisation of girls and young women (the female population >13 years of age) it was possible to a wide extent to close immunity gaps in young adults which occurred in the pre-vaccination era. In 1998 in the cohort of the 18–30-year-old population only 0.8–3% of the women were seronegative for rubella, compared to 5–13% of the men. Differences regarding immunity between old and new federal Länder are no longer existent, although vaccination against rubella was only introduced in the new Länder after the reunification. Above all, a potential risk for pregnant women without protection against rubella is conferred by the high percentage of pre-school children without rubella immunity. This is due to the delay in starting to vaccinate small children, but also to a lower acceptance of the combined vaccination. Compared to countries like Finland, Sweden or the United States, which have almost achieved the elimination of congenital rubella syndrome (CRS), in Germany a considerable number of individuals remain susceptible to this infection. Continuous endemic virus circulation endangers the main target group of rubella vaccination, i. e. women in the early stages of pregnancy. Only when MMR vaccination rates of more than 90% are achieved in small children in the course of their second year of life, there will be a real chance in Germany to eradicate not only measles, but also the CRS over the next 10 years.     

山东省实施儿童风疹疫苗免疫后风疹发病年龄变化趋势的分析

目的分析山东省自1995年开始实施儿童风疹疫苗免疫后风疹发病年龄的变化趋势。方法对1999—2004年通过麻疹疫情专报系统得到的风疹疫情资料以及风疹疫苗接种情况进行分析。结果1999—2004年山东省风疹年平均报告发病率为0．59／10万，多为暴发（占总病例数的81．17％）；发病主要集中在7～15岁学龄儿童（77．77％），7岁以下发病较少（占7．93％），发病年龄中位数分别为10．37岁、11．66岁、11．41岁、12．81岁、14．28岁和13．96岁，发病高峰年龄逐年后移，成人发病有所增加；学龄前儿童风疹疫苗基础免疫估算接种率约为60％，学龄儿童约为20％。结论风疹发病年龄后移，将威胁育龄期妇女，增加发生先天性风疹综合征的危险性；应在继续做好儿童风疹免疫的同时，积极开展育龄期妇女风疹抗体筛查及疫苗接种工作。     

风疹爆发应急接种的预防效果研究

目的　探讨风疹应急性预防接种的效果 ,为控制风疹爆发疫情提供依据。方法　对某市 8所小学风疹爆发流行进行流行病学调查 ,首先利用 1所小学自然爆发至终止的数据建立本次风疹爆发的Reed -Frost模型 ,以此模型预测其它 7所经应急性预防接种的小学的理论风疹发病人数 ,进而预测应急性预防接种的预防效果。结果　 7所小学风疹的理论显性发病例数 1 0 0 0例 ,应急性预防接种减少风疹发病 92 5例。结论　在发生风疹爆发的小学应尽早进行风疹疫苗的应急接种 ,以控制风疹爆发疫情的蔓延     

A model-based design of a vaccination strategy against rubella in a non-immunized community of S?o Paulo State,Brazil.

A mixed vaccination strategy against rubella is proposed. We describe how the vaccination strategy was designed with the help of mathematical techniques. The strategy was designed for application in a non-immunized community of the State of São Paulo, Brazil, and was implemented by local health authorities in 1992. This strategy comprises a pulse vaccination campaign, covering the age interval between 1 and 10 years, followed by the introduction of the vaccine in the immunization calendar at 15 months of age. The expected impact of the proposed strategy is discussed.     

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。     

Prevalence of childhood exanthematic disease antibodies in paramedical students: need of vaccination

The immunity to common childhood exanthematic diseases such as varicella, rubella, mumps and measles was evaluated in 1024 students of the degree courses of health professions at Padua University Medical School. Subjects were subdivided according to gender and age (25 years old or less, and older than 25 years). Results showed that the prevalence of positive antibodies (IgG) to varicella and rubella (94.1 and 94.5%, respectively) was significantly higher (p<0.001) than mumps (78.6%) and measles (86.3%). In addition, measles showed a significant higher prevalence than mumps (p<0.001). Prevalence of positive antibodies to rubella in females (97.4%) was significantly higher (p<0.001) than males (87.5%), but only if aged 25 years or less. Furthermore, males older than 25 years were significantly more immune (p<0.001) to measles (93.0%) than younger ones (84.3%). A vaccination strategy was applied but compliance was less than 50%; in addition, about 40.0% of vaccinated subjects eluded control after vaccination. Seroconversion after vaccine appeared high for rubella, mumps and measles (92.3, 88.9 and 88.1%, respectively), but low for varicella (43.8%).     

Rubella seroprevalence among primary and pre- primary school pupils at Moi's Bridge location, Uasin Gishu District, Kenya

Background  

Rubella is an infectious and generally mild childhood viral disease. The disease is of public health importance because infection acquired during early pregnancy often results in foetal abnormalities that are classified as congenital rubella syndrome (CRS). The burden of rubella infection in most developing countries in not well documented because of limited epidemiological data. However, availability of an effective vaccine has made it necessary to have all the countries with no routine vaccination schedule to evaluate the burden of disease in order to make informed decisions on rubella vaccination and strategy. To address this gap we conducted a study to determine age-specific rubella seroprevalence rates and related risk factors among primary and pre-primary school children in Uasin Gishu district, Moi's Bridge location of Kenya.     

Risk of pregnancy among adolescent schoolgirls participating in a measles mass immunization program

A large measles vaccination program in the Albuquerque, New Mexico public schools in 1981, conducted according to US Public Health Service guidelines, was studied to determine rates of pregnancy among adolescent vaccinees. Pre-vaccination counseling of 1,922 clinic attendees prevented seven pregnant girls from being vaccinated. Despite counseling, of 1,913 female vaccinees age 13-18 years old, two were pregnant at the time of vaccination (1.05 pregnancies per 1,000 vaccinees) and an additional four girls became pregnant in the three months after vaccination (2.1 pregnancies per 1,000 vaccinees). Data supporting low or absent fetal risks from measles and rubella vaccine, combined with the low pregnancy rate among vaccinees documented in this study, support the reasonableness of the recommended strategy for measles and rubella vaccination of secondary schoolgirls.     

Immunization of Adolescents: Recommendations of the Advisory Committee on Immunization Practices, the Amerii Academy of Pediatrics, the American Academy of Family Physicians, and the American Medical Association

SUMMARY: This report concerning the immunization of adolescents (ie, persons 11–21 years of age, as defined by the American Medical Association [AMA] and the American Academy of Pediatrics [AAP]) is a supplement to previous publications (ie, MMWR 1994;43[No. RR-1] 1–38; the AAP 1994 Red Book: Report of the Committee on Infectious Diseases; Summary of Policy Recommendations for Periodic Health Examination, August 1996 from the American Academy of Family Physicians [AAFP]; and AMA Guidelines for Adolescent Preventive Services [GAPS]: Recommendations and Rationale). This report presents a new strategy to improve the delivery of vaccination services to adolescents and to integrate recommendations for vaccination with other preventive services provided to adolescents. This new strategy emphasizes vaccination of adolescents 11–12 years of age by establishing a routine visit to their health-care providers. Specifically, the purposes of this visit are to a) vaccinate adolescents who have not been previously vaccinated with varicella virus vaccine, hepatitis B vaccine, or the second dose of the measles, mumps, and rubella (MMR) vaccine; b) provide a booster dose of tetanus and diphtheria toxoids; c) administer other vaccines that may be recommended for certain adolescents; and d) provide other recommended preventive services. The recommendations for vaccination of adolescents are based on new or current information for each vaccine. The most recent recommendations from AC1P, AAP, AAFP, and AMA concerning specific vaccines and delivery of preventive services should be consulted for details.     

Are they protected? Immunity to vaccine‐preventable diseases in healthcare workers at an Australian hospital

Objective : Australian guidelines for healthcare worker (HCW) vaccination were updated in 2010, and pre‐employment assessment of new employees has previously been identified as a priority. We determined the vaccination status of a cohort of existing HCWs at a tertiary hospital in Melbourne, Victoria. Methods : Random sampling of HCWs employed prior to 2006 with unknown/incomplete immunisation status was conducted between April and August 2011. Immunity to vaccine‐preventable diseases (VPDs) was determined serologically (hepatitis B, varicella, measles, mumps, rubella) and by questionnaire (diphtheria, tetanus and pertussis), with vaccination by a nurse immuniser. Results : Overall, 95 HCWs were evaluated. Mean age and duration of employment were 47.2 and 12.6 years, respectively. Forty‐seven staff (49%) required vaccination to comply with Australian immunisation guidelines: 18% were non‐immune to hepatitis B, 2% to varicella, 8% to measles, 19% to mumps and 13% to rubella. HCWs without serological hepatitis B immunity were all staff with clinical roles. Total costs were $7,527.34 (mean $222.79/HCW). Conclusions : Immunity to VPDs among existing HCWs was inadequate. About half assessed HCWs were non‐immune to at least one VPD, and non‐immunity to hepatitis B was high. A comprehensive assessment strategy for existing employees is required to enhance vaccination coverage and compliance with national guidelines. Implications : Adequately resourced ‘look‐back’ immunisation assessment programs are required to reduce the risks of VPDs among existing staff and patients. Review of current approaches and national consensus regarding the need for mandatory strategies would assist this process.     

Changes of the immunological patterns against measles, mumps and rubella. A vaccination programme studied 3 to 7 years after the introduction of a two-dose schedule

A two-dose vaccination programme using a combined measles, mumps and rubella vaccine (MMR) and administration at the ages of 18 months and 12 years was introduced in 1982. The 12-year-old schoolchildren were tested yearly from 1985 to 1989 on serum samples obtained prior to and after vaccination. Each year between 420 and 756 children were tested. The method used for antibody testing was the haemolysis-in-gel (HIG) assay. For measles also the enzyme-linked immunosorbent assay (ELISA) and the neutralization titre (NT) were applied. Only minor variations of the prevaccination immunity to measles were seen during the period 3-7 years after introduction of the programme. The age groups studied had partly been vaccinated against measles earlier. Between 12 and 16% lacked prevaccination immunity. In contrast the immunity to mumps and rubella of the 12-year-old children decreased considerably during the study period. No general vaccination against these diseases had been performed. Thus the susceptibility to mumps increased from 14% in 1985 to 39% in 1989 and to rubella from 41 to 57%. The seroconversion rate of children seronegative for measles was high, i.e. 100% in 1985 and later varied between 96 and 97%. For mumps, the seroconversion rate was lower and varied between 72 and 88%. All sera converted to rubella. During the follow-up period there was a declining incidence of measles, mumps and rubella. The relationship between the vaccination and reduction of disease and natural immunity strongly suggests that the association is causal and that this vaccination policy reduced the transmission of infection.     

Progress toward elimination of rubella and congenital rubella syndrome--the Americas, 2003-2008

In 2003, the Pan American Health Organization (PAHO) adopted a resolution calling for rubella and congenital rubella syndrome (CRS) elimination in the Americas by the year 2010. Elimination was defined as the interruption of endemic rubella virus transmission in all countries of North America, Central America, South America, and the Caribbean for more than 12 months and no occurrence of CRS cases attributed to endemic transmission. To accomplish this goal, PAHO developed a rubella and CRS elimination strategy (3) to 1) introduce rubella-containing vaccine (RCV) into routine vaccination programs of all countries for children aged 12 months and reach >/=95% coverage in all municipalities, 2) conduct a one-time mass campaign among adolescents and adults and periodic follow-up campaigns among children aged <5 years, and 3) integrate rubella surveillance with measles surveillance and initiate CRS surveillance. During 1998-2006, confirmed rubella cases decreased 98% (from 135,947 to 2,998) in the Americas. However, in 2007, rubella outbreaks with a total of 13,014 cases occurred in three countries (Argentina, Brazil, and Chile), primarily in males not included in previous vaccination campaigns. This report summarizes overall progress toward reaching the 2010 goal of eliminating rubella and CRS. With completion of campaigns in Argentina, Brazil, and Haiti, all countries will have implemented the recommended PAHO strategy by the end of 2008, with the expectation of reaching the 2010 rubella and CRS elimination goal.