Hepatitis a vaccination coverage among children aged 24-35 months--United States, 2003

Hepatitis A vaccine was first licensed in the United States in 1995. In 1996, the Advisory Committee on Immunization Practices (ACIP) recommended vaccination of children aged >/=24 months in populations with the highest incidence of hepatitis A (e.g., American Indian/Alaska Native [AI/AN], Asian/Pacific Islander, and selected Hispanic and religious communities). In 1999, these guidelines were expanded to recommend routine vaccination for children residing in 11 states where average annual hepatitis A incidence during 1987-1997 was at least 20 per 100,000 population (twice the national average) and to consider routine vaccination for children in six states where average annual incidence was 10-20 per 100,000 population. This report is the first national analysis of hepatitis A vaccination coverage among children. The results indicate that, in 2003, vaccination coverage levels with at least 1 dose of hepatitis A vaccine for children aged 24-35 months varied from 6.4% to 72.7% in areas where routine vaccination is recommended. In addition, hepatitis A vaccination coverage rates for children aged 24-35 months are lower than overall rates for other vaccines recommended for children. Sustaining and improving vaccination coverage among young children is needed to ensure continued declines in hepatitis A incidence in the United States.     

Effectiveness and impact of the hepatitis B vaccination program in preadolescents in Catalonia 21 years after its introduction

Hepatitis B is a viral disease of global importance. In Catalonia in the 1980s, the seroepidemiological pattern of HBV infection was low-intermediate. In 1990, the Expert Committee on Vaccinations of the Department of Health of the Generalitat of Catalonia evaluated the systematic introduction of hepatitis B vaccination in preadolescents, maintaining the vaccination of risk groups. The objective of this study was to estimate the effectiveness and impact of the systematic hepatitis B vaccination programme in preadolescents in Catalonia 21 years after its introduction. A retrospective cohort study was conducted, comparing the disease incidence in vaccinated and unvaccinated cohorts. Cases of hepatitis B were defined as those reported by the General Subdirectorate of Surveillance and Response to Public Health Emergencies between 2000 and 2014. The incidence rate was 2.5 per 100,000 persons in 1991 and 1.2 per 100,000 persons in 2014, a reduction of 52%. During the study period, 388 cases of hepatitis B infection were notified, of which three were classified as vaccine failures. Vaccine effectiveness was 99.30% (95% CI: 97.83–99.78) and the population prevented fraction in the cohorts of preadolescents studied was 64.56% (95% CI: 60.45–68.66). The effectiveness and impact of the hepatitis B vaccination program in preadolescents in Catalonia is high, with the consequent benefits for the population.     

Vaccination campaign against meningococcal disease in army recruits in Italy

A high attack rate (17.3/100,000) of meningococcal disease in army recruits in Italy, with 95% of the cases due to serogroup C, constituted the motivating factors to make bivalent serogroup A + C meningococcal vaccination compulsory by law for army recruits starting January 1987. Because the vaccine was given only to the new recruits entering the army, full coverage was not achieved until January 1988. Nearly 900,000 subjects (300,000 yearly) were vaccinated between January 1987 and December 1989. There were no reports of any untoward reactions to the vaccine. Of the 300,000 recruits in service each year, 52, 21, 15, 5 and 4 cases of the disease occurred in 1985, 1986, 1987, 1988 and 1989, respectively (P less than 0.001). Of the 24 cases occurring since the start of the vaccination, only two (due to serogroup C) were attributable to vaccine failure. The remaining cases were in unvaccinated recruits (15 cases) or were due to serogroups other than A or C (7 cases). The cumulative incidence of meningococcal serogroup C in the 600,000 vaccinated recruits during the period 1988-89 was 0.2/100,000 (1 case amongst 600,000 recruits), while the corresponding figure in the 600,000 unvaccinated recruits during the period 1985-6 was 11.3/100,000 (68 cases amongst 600,000 recruits) (P less than 0.001). The protective efficacy of the vaccine in 1987 was 91.2% (12 cases of meningococcal serogroup A and C disease from an average of 150,000 unvaccinated recruits observed for 1 year, and 1 case from the corresponding average of 150,000 vaccinated ones). In 1988 and in 1989 this figure could not be calculated because all recruits were vaccinated.(ABSTRACT TRUNCATED AT 250 WORDS)     

Hepatitis A vaccination coverage among adults aged 18–49 years in the United States

Background

Hepatitis A is the most common type of hepatitis reported in the United States. Prior to hepatitis A vaccine introduction in 1996, hepatitis A incidence followed a cyclic pattern with peak incidence occurring every 10–15 years. During 1980–1995, between 22,000 and 36,000 hepatitis A cases were reported annually. Since 1996, hepatitis A vaccination recommendations have included adults at risk for infection and children living in communities with the highest disease rates. This study provides the first national estimates of self-reported hepatitis A vaccination coverage among persons aged 18–49 years in the United States.

Methods

We analyzed the 2007 National Immunization Survey-Adult (NIS-Adult) data with restrictions to individuals aged 18–49 years. National estimates of hepatitis A vaccination coverage were calculated based on self-report and multivariable logistic regression analysis was used to identify factors independently associated with hepatitis A vaccination status.

Results

Among adults aged 18–49 years, 12.1% (95% confidence interval, CI = 9.9–14.8%) had received two or more doses of hepatitis A vaccine in 2007. Hepatitis A vaccination coverage was significantly higher among adults aged 18–29 years (15.6%) and adults aged 30–39 years (12.9%) compared with adults aged 40–49 years (8.3%). Coverage was significantly lower for Hispanics (7.1%) compared with non-Hispanic whites (12.5%). Characteristics independently associated with a higher likelihood of hepatitis A vaccination among persons aged 18–49 years included younger age groups, persons at or above poverty level, persons with public medical insurance, and persons who received influenza vaccination in the past season.

Conclusions

In 2007, self-reported hepatitis A vaccination coverage among adults aged 18–49 years was 12.1%. These data provide the first national hepatitis A vaccination coverage estimates among adults and are very important in planning and implementing strategies for increasing hepatitis A vaccination coverage among adults at risk for hepatitis A.     

Hepatitis B vaccination coverage levels among healthcare workers in the United States, 2002-2003.

BACKGROUND: Hepatitis B virus (HBV) infection is a well recognized risk for healthcare workers (HCWs), and routine vaccination of HCWs has been recommended since 1982. By 1995, the level of vaccination coverage among HCWs was only 67%. OBJECTIVE: To obtain an accurate estimate of hepatitis B vaccination coverage levels among HCWs and to describe the hospital characteristics and hepatitis B vaccination policies associated with various coverage levels. DESIGN: Cross-sectional survey. METHODS: A representative sample of 425 of 6,116 American Hospital Association member hospitals was selected to participate, using probability-proportional-to-size methods during 2002-2003. The data collected included information regarding each hospital's hepatitis B vaccination policies. Vaccination coverage levels were estimated from a systematic sample of 25 HCWs from each hospital whose medical records were reviewed for demographic and vaccination data. The main outcome measure was hepatitis B vaccination coverage levels. RESULTS: Among at-risk HCWs, 75% had received 3 or more doses of the hepatitis B vaccine, corresponding to an estimated 2.5 million vaccinated hospital-based HCWs. The coverage level was 81% among staff physicians and nurses. Compared with nurses, coverage was significantly lower among phlebotomists (71.1%) and nurses' aides and/or other patient care staff (70.9%; P<.05). Hepatitis B vaccination coverage was highest among white HCWs (79.5%) and lowest among black HCWs (67.6%; P<.05). Compared with HCWs who worked in hospitals that required vaccination only of HCWs with identified risk for exposure to blood or other potentially infectious material, hepatitis B vaccination coverage was significantly lower among HCWs who worked in hospitals that required vaccination of HCWs without identified risk for exposure to blood or other potentially infectious material (76.6% vs 62.4%; P<.05). CONCLUSIONS: In the United States, an estimated 75% of HCWs have been vaccinated against hepatitis B. Important differences in coverage levels exist among various demographic groups. Hospitals need to identify methods to improve hepatitis B vaccination coverage levels and should consider developing targeted vaccination programs directed at unvaccinated, at-risk HCWs who have frequent or potential exposure to blood or other potentially infectious material.     

宁波市实施乙型肝炎疫苗计划免疫后儿童乙型肝炎病毒血清流行病学研究

目的了解宁波市实施乙型肝炎疫苗(乙肝疫苗)计划免疫7年后,儿童乙型肝炎病毒(HBV)感染及免疫状况.方法采用整群分层抽样法调查1982～1995年出生儿童血清HBsAg和抗-HBs阳性率(RIA法).结果①1992～1995年出生的免疫人群HBsAg阳性率为2.66%,比未免疫人群(10.95%)下降了75.71%(χ2=22.91,P＜0.0001);②免疫人群抗-HBs阳性率达65.95%,显著高于未免疫人群的41.03%(χ2=113.67,P＜0.0001);③在计划免疫后的第5～7年起显现了免疫人群HBsAg阳性率升高和抗-HBs阳性率下降的迹象.结论宁波市实施乙肝疫苗计划免疫7年后,儿童对HBV已呈现出高免疫、低感染的特征;但需进一步研究计划免疫4～5年后,免疫人群HBsAg阳性率升高、抗-HBs阳性率下降的现象和乙肝疫苗加强免疫的适时问题.     

Study of incidence of measles and vaccination coverage in Ahmedabad urban slums

Measles incidence and vaccination coverage survey was carried out in Ahmedabad urban slums in February 2000. A total of 3073 children between 9 to 59 months were studied. The incidence rate of measles was 11.2% (95% C.I-10.04-12.36). Measles vaccination coverage was only 59.88%. There was no gender difference in vaccine coverage or measles incidence rate. Diarrhoea was the most common complication observed among both vaccinated and unvaccinated children and it was significantly more among unvaccinated children. Among 1840 vaccinated children only 529 (28.75%) children received vitamin A along with measles vaccination.     

深圳市儿童扩大国家免疫规划疫苗接种率调查

目的 了解深圳市儿童扩大国家免疫规划疫苗接种情况,为制定免疫规划相关政策提供参考依据. 方法 按照预防接种门诊地理位置分布随机抽取123间门诊,共调查3 696名2008年1月1日-2010年12月31日出生的儿童的流脑疫苗和甲肝疫苗接种率. 结果 调查适龄儿童A群流脑多糖疫苗第1剂、A群流脑多糖疫苗第2剂、甲肝疫苗及A＋C群流脑多糖疫苗第1剂接种率分别为93.6％、87.9％、87.4％、81.2％.除A群流脑多糖疫苗第1剂外,其它疫苗不同剂次接种率地区差异有统计学意义（P＜0.05）,福田区、南山区较高.不知道要接种（46.7％）、孩子患病未去接种（27.3％）、忘记接种（14.0％）,还有家中无人带孩子去接种（12.0％）是儿童未接种疫苗的原因. 结论 深圳市儿童扩大免疫疫苗接种率总体较高,不同地区之间存在差别,应通过扩大宣传、正确掌握疫苗接种禁忌证,提高疫苗接种率.     

2004 - 2016年荆州市甲型病毒性肝炎流行特征分析

目的 分析2004 - 2016年荆州市甲型病毒性肝炎（甲肝）流行病学特征并提出防控建议。方法 采用描述性流行病学方法分析2004 - 2016年荆州市甲肝疫情资料,采用集中度值法分析甲肝季节特征,采用系统聚类分析甲肝地区分布特征。结果 荆州市2004 - 2016年共报告甲肝2 232例,年均发病率为2.89/10万,13年间荆州市甲肝发病率呈下降趋势（χ2 （趋势） = 158.445,P＜0.05）,年平均下降速度为5.93％。各年份发病无明显季节性。地区发病顺位为:城乡结合部＞中心城区＞远郊（χ2 = 31.907,P＜0.05;χ2 = 15.178,P＜0.05）。男性发病高于女性（χ2 = 18.268,P＜0.05）,人群分类以农民为主（62.10％）。发病高峰年龄:2004 - 2008年病例以30～54岁为主,2008 - 2012年病例以35～59岁为主,2013 - 2016年病例以40～69岁为主,病例发病年龄有后移现象。2009以来荆州市甲肝疫苗报告接种率均在99％以上。结论 2004 - 2016年荆州市甲肝发病呈下降趋势,甲肝疫苗预防接种为主的预防控制措施成效明显。今后应在进一步做好小年龄组儿童免疫接种工作的同时,加强高发地区高危人群的疫苗接种工作。     

广东省新生儿乙型肝炎疫苗免疫效果分析和免疫策略探讨

目的分析广东省新生儿乙型肝炎疫苗的免疫效果,为制定广东省乙型肝炎疫苗免疫策略提供依据。方法分析广东省1992~2003年乙型肝炎疫苗接种率、乙型肝炎发病率和人群乙肝病毒表面抗原(HBsAg)携带率等资料。结果乙肝疫苗1992年纳入计划免疫管理,2002年纳入计划免疫,新生儿乙肝疫苗免疫逐渐完善,1997年、2003年新生儿乙型肝炎疫苗接种率分别为73.6%、93.1%;1993~2003年乙型肝炎平均报告发病率为33.80/10万,从1993年的28.85/10万上升至2003年的33.00/10万,其中0~4岁组和5~9岁组分别由17.05/10万、26.10/10万下降至6.36/10万、6.72/10万;1~59岁人群HBsAg携带率由1992年的16.76%下降至2002年的13.28%,其中1~4岁组和5~9岁组分别由16.76%1、9.14%降至4.86%、6.39%,10~59岁组变化不大。结论实施新生儿乙肝疫苗免疫能显著地降低乙肝发病率和HBsAg携带率;今后在实施新生儿乙肝疫苗免疫的同时,应考虑开展对未接种过乙肝疫苗的儿童和重点人群进行乙肝疫苗免疫。     

Hepatitis A vaccination coverage among children aged 24-35 months--United States, 2004-2005

After the licensure of hepatitis A vaccine in 1995 for children aged > or =24 months, the Advisory Committee on Immunization Practices (ACIP) incrementally expanded the proportion of children for whom it recommended the vaccine. In 1996, ACIP recommended vaccinating children in communities that had high rates of hepatitis A virus (HAV) infection, including American Indian/Alaska Native (AI/AN) communities and selected Hispanic and religious communities. In 1999, ACIP extended the recommendation to include routine vaccination for all children living in states, counties, and communities with incidence rates twice the 1987-1997 national average of 10 cases per 100,000 population (i.e., > or =20 cases per 100,000 population); ACIP also recommended considering vaccination for children living in states, counties, and communities with incidence rates exceeding the 1987-1997 national average (i.e., >10 to <20 cases per 100,000 population). National estimates of hepatitis A vaccination coverage were first made available through the 2003 National Immunization Survey (NIS), which indicated an overall national 1-dose coverage level of 16.0% (range: 6.4%-72.7%) among children aged 24-35 months. The estimates in this report update those findings by including 2 additional years of data (2004 and 2005). National 1-dose vaccination-coverage levels among children aged 24-35 months increased from 17.6% in 2004 to 21.3% in 2005. Coverage in states where vaccination was recommended (overall in 2005: 56.5%; range: 12.9%-71.0%) was below those for other recommended childhood vaccinations, such as varicella (87.5% in 2004). Despite low hepatitis A vaccination-coverage levels compared with other recommended childhood vaccinations, incidence of acute HAV infections have declined to the lowest level ever recorded. The 2005 licensure of the hepatitis A vaccine for use in younger children (aged > or =12 months) and the 2006 ACIP guideline for routine hepatitis A vaccination of all children aged > or =12 months should result in improved vaccination coverage and further reductions in disease incidence.     

Hepatitis B vaccination coverage among adults--United States, 2004

Hepatitis B virus (HBV) infection is a major cause of cirrhosis and liver cancer in the United States. The Advisory Committee on Immunization Practices (ACIP) has recommended a comprehensive strategy to eliminate HBV transmission, including prevention of perinatal HBV transmission; universal vaccination of infants; catch-up vaccination of unvaccinated children and adolescents; and vaccination of unvaccinated adults at increased risk for infection. The incidence of acute hepatitis B has declined 75%, from 8.5 per 100,000 population in 1990 to 2.1 per 100,000 population in 2004, with the greatest declines (94%) among children and adolescents. Incidence remains highest among adults, who accounted for approximately 95% of the estimated 60,000 new infections in 2004. To measure hepatitis B vaccination coverage among adults, data were analyzed from the 2004 National Health Interview Survey (NHIS). This report summarizes the results of that analysis, which indicated that, during 2004, 34.6% of adults aged 18-49 years reported receiving hepatitis B vaccine, including 45.4% of adults at high risk for HBV infection. To accelerate elimination of HBV transmission in the United States, public health programs and clinical care providers should implement strategies to ensure that adults at high risk are offered hepatitis B vaccine.     

甲型肝炎减毒活疫苗（H2株）10年流行病学效果观察

目的：观察在甲型肝炎（甲肝）高发县、区用甲肝减毒活疫苗（H2株）大面积接种后长期的流行病学保护效果。方法：选择浙江省嵊泗县和椒江区二个试点,二组小学生定群研究,观察4年。试点内1－15岁儿童普遍接种甲肝活疫苗,部分研究对象作血清中和试验。免疫回忆反应及免后10年抗体检测。结果：接种组与未接种组甲肝发病率判别具有显著性（P＜0．01）,疫苗保护率为100％。疫苗接种率与甲肝发病率二者具有明显负相关,全人口甲肝发病率分别下降了94．5％和90．3％,1－15岁儿童组发病专率分别下降了96．9％和97．9％,10年期间没有发生甲肝流行血清学检测结果：免后阴性血清,用体外中和法验证有63．8％仍有中和作用,加强免疫1针后回忆反应明显。免后10年抗－HAV－IgG的阳性率为80．2％,结论：甲肝减毒活疫苗（H2株）长期的流行病学效果明显。通过普遍接种甲肝活疫苗,第一次在甲肝高发地区和高发年龄组消除了甲肝的发生与流行。     

甲型肝炎减毒活疫苗(H_2株)10年流行病学效果观察

目的　观察在甲型肝炎 (甲肝 )高发县、区用甲肝减毒活疫苗 (H2 株 )大面积接种后长期的流行病学保护效果。方法　选择浙江省嵊泗县和椒江区二个试点。二组小学生定群研究 ,观察 4年。试点内 1～ 15岁儿童普遍接种甲肝活疫苗。部分研究对象作血清中和试验、免疫回忆反应及免后 10年抗体检测。结果　接种组与未接种组甲肝发病率差别具有显著性 (P <0 .0 1) ,疫苗保护率为10 0 %。疫苗接种率与甲肝发病率二者具有明显负相关。全人口甲肝发病率分别下降了 94.5 %和90 .3% ,1～ 15岁儿童组发病专率分别下降了 96 .9%和 97.9% ,10年期间没有发生甲肝流行。血清学检测结果 :免后阴性血清 ,用体外中和法验证有 6 3.8%仍有中和作用 ,加强免疫 1针后回忆反应明显。免后 10年抗 HAV IgG的阳性率为 80 .2 %。结论　甲肝减毒活疫苗 (H2 株 )长期的流行病学效果明显。通过普遍接种甲肝活疫苗 ,第一次在甲肝高发地区和高发年龄组消除了甲肝的发生与流行     

Increasing hepatitis B vaccine coverage in prisons in England and Wales

The most frequently reported risk factor for hepatitis B infection in England and Wales is injecting drug use (38%). Since approximately 61% of injecting drug users (IDUs) had been imprisoned and less than 40% had received hepatitis B vaccine, a prison based hepatitis B vaccination programme was set up in 2001. At the 42 establishments participating in this study, all prisoners were offered vaccine at reception. Prisoners over 18 years were vaccinated using the 0, 7 and 21 days schedule and those under 18 years, using the 0, 1 and 2 months schedule. As far as possible a fourth dose was given to all after 12 months. In 2003, 14,163 prisoners received at least one dose of vaccine and altogether 26,265 doses were administered. A further 1111 prisoners reported they had already been vaccinated against hepatitis B. The median vaccine coverage rate was 17% (range 0-94%). Despite low coverage levels, the vaccination programme in prisons can be said to have vaccinated a sizable number of young, male prisoners, a group that have previously been shown to be at high risk of infection. The prisons which achieved vaccine coverage levels over 50% had designated nursing staff who ran the vaccination clinics.     

苏州地区b型流感嗜血杆菌结合疫苗对减少儿童住院肺炎有效性的观察性研究

  目的  评价接种不同剂次b型流感嗜血杆菌(Haemophilus influenzae type b, Hib)结合疫苗对儿童住院肺炎的保护效果(vaccine effectiveness, VE)。  方法  采用回顾性队列研究设计,以2018年出生并在苏州大学附属儿童医院住院的苏州地区常住儿童为研究对象,分别通过苏州大学附属儿童医院卫生信息系统和苏州市疾病预防控制中心疫苗登记数据库收集研究对象在2019年6月30日之前因肺炎住院的相关医疗信息以及Hib疫苗接种信息,比较不同剂次Hib疫苗接种组和未接种组的住院肺炎发生率,计算Hib疫苗保护效果。  结果  2018年1月1日-2019年6月30日苏州地区儿童Hib疫苗的首剂接种率为18.8%(10 080/53 753);住院肺炎发生率随接种剂次的增加而降低(χ2=-4.31, P < 0.001),其中1剂次Hib疫苗未显示保护效果,2剂次Hib疫苗已显示出保护趋势,但差异无统计学意义,接种3剂次及以上Hib疫苗的儿童住院肺炎发生率低于未接种组(RR=0.72, 95% CI: 0.59~0.89, P＜0.001),且可预防的住院肺炎发生率为1 514.8/105人年,保护效果为28%(95% CI: 11%~41%)。  结论  苏州地区3剂次及以上Hib疫苗接种可降低儿童因肺炎住院的发生率,建议推广儿童Hib疫苗接种工作,提高Hib疫苗覆盖率。     

2003～2010年贵德县新生儿乙型肝炎疫苗接种效果分析

[目的]了解贵德县新生儿乙型肝炎疫苗接种效果,为指导和落实乙肝免疫预防策略提供科学依据。[方法]对2003～2010年贵德县乙肝疫苗接种资料、2008～2010年每年对托幼机构全程接种乙肝疫苗后的1～6岁儿童开展乙肝病毒表面抗原(HBsAg)、乙肝病毒表面抗体(抗-HBs)检测资料进行分析。[结果]2003～2010年合计接种新生儿10 720人,应接种10 955人,全程接种率为97.85%;首剂及时接种9 247人,应接种11 088人,首剂及时接种率为83.40%。全程、首针及时报告接种率,2003年分别为90.23%、40.30%,2010年分别为99.67%、98.73%。2008～2010年合计调查全程接种乙肝疫苗后的儿童1 446名,抗-HBs阳性的1 125人,阳性率为77.80%。抗-HBs阳性率,各年份分别为71.60%、78.87%、81.75%(P<0.01);城镇、农村、牧区分别为81.87%、78.09%、65.50%(P<0.01);≤2岁为82.05%、3岁为83.51%、4岁为77.72%,5岁为76.19%,6岁为69.17%(P<0.01)。[结论]贵德县乙肝疫苗全程接种率和首剂及时率逐年提高,但抗-HBs阳性率随年龄增长呈下降趋势。     

Influenza vaccine in healthy preschool children

BACKGROUND: Studies of influenza vaccination in healthy children have not definitely answered the question of their efficacy. METHODS: We have carried out a randomized trial in a well selected population of healthy preschool children in Sardinia, Italy. During October 1995, 344 children aged 1 to 6 years, were randomly assigned to receive influenza vaccine (n=177) or no treatment (n=167). Two doses of a trivalent subvirion vaccine, containing 15mg of highly purified surface antigens from the component strains A/Johannesburg/33/94-like, A/Singapore/6/86-like and B/ Beijing/184/ 93-like were administered. Follow-up data were collected from December 1, 1995 through April 30, 1996. RESULTS: Seroconversion was documented in 17 out of 17 children. No specific systemic symptoms or severe local reactions were observed after vaccination. Influenza-like episodes, defined by the presence of fever and cough or sore throat that lasted at least 72 hours, occurred in 63 (37.7%) of unvaccinated children and in 22 (12.4%) of vaccinated ones. The corresponding reduction in disease incidence was 67% (95% CI: 0.59-0.74). Three episodes of otitis were observed among children in the control group versus zero among vaccinated children (p=0.07). Mean duration of day care center absenteism was significantly reduced by vaccination (2.3 days in unvaccinated and 0.5 day in vaccinated children, p<0.001) CONCLUSIONS: Influenza vaccine is safe and effective in healthy preschool children. However the favourable implications of vaccination on disease rate in subsequent years have to be evaluated.     

Effectiveness of a mass hepatitis A vaccination program in preadolescents

A program of mass hepatitis A+B vaccination in preadolescents in schools was begun in the Catalonia in the last quarter of 1998. This study investigated the impact of the program by comparing the incidence of hepatitis A in vaccinated and unvaccinated cohort.The greatest reduction of the incidence rate of hepatitis A was observed in the 10-14 years age group, from 10.3 per 100000 persons-year in the period 1996-1998 to 1.8 per 100000 persons-year in the period 1999-2001. The global incidence decreased from 6.2 to 2.6 per 100000 persons-year.After analysis of cases occurring in the vaccinated and non vaccinated cohort, the effectiveness of the vaccination program was estimated at 97.0% (95% CI: 78.6-99.6).     

Direct and indirect impact on rotavirus positive and all-cause gastroenteritis hospitalisations in South Australian children following the introduction of rotavirus vaccination

Rotavirus vaccine for infants was introduced into the National Immunisation Program in Australia in July 2007. To determine the impact of rotavirus vaccination on gastroenteritis hospitalisations amongst children less than six years of age in South Australia, we conducted a retrospective analysis of hospital admissions over two time periods: 1 May 2005-30 April 2007 (prior to rotavirus vaccination introduction) and 1 May 2008-30 April 2010 (post rotavirus vaccination introduction). The introduction of rotavirus vaccination has been associated with a marked reduction in hospital admissions for serious rotavirus gastroenteritis (RVGE) and all-cause gastroenteritis (ACGE). Following the introduction of rotavirus vaccination in South Australia, there was an 83% reduction in RVGE coded admissions (955 vs 165) and a 48% reduction in ACGE coded admissions (4153 vs 2142) for children aged less than six years. Children less than two years demonstrated the greatest reduction (90%) in RVGE admissions and ACGE admissions (57%). Age-specific RVGE hospitalisation rates decreased from 933/100,000 prior to rotavirus vaccine introduction to 88/100,000 for children less than two years of age. In addition, for gastroenteritis hospitalisations for children aged five years at time of admission (unvaccinated cohort) there was a reduction in the number of RVGE cases (24 vs 4), a reduction in age-specific RVGE hospitalisation rates (65/100,000 vs 11/100,000) and a significant reduction in the proportion of overall gastroenteritis cases which were rotavirus positive (11.5% vs 3.5%), suggesting a positive impact on both unvaccinated and vaccinated children less than six years of age in South Australia.