Effectiveness of a hepatitis A vaccination program for migrant children in Amsterdam, The Netherlands (1992-2004)

A Study of Hepatitis A Seroprevalence in a Paediatric and Adolescent Population of the Province of Florence (Italy) in the Period 2017-2018 Confirms Tuscany a Low Endemic Area

Background: Italy is considered an area with very low HAV (hepatitis A virus) endemicity. Currently in Italy the anti-HAV vaccine is recommended only for specific risk groups and there is no universal vaccination program. The aim of this study was to assess the level of immunity against hepatitis A in a sample of children and adolescents from the province of Florence. Methods: A total of 165 sera were collected from subjects aged 1 to 18 years, proportionally selected according to the general population size and stratified by age and sex. A qualitative evaluation of anti-HAV antibodies was performed using the enzyme-linked immunosorbent assay (ELISA). Anamnestic and vaccination status data were also collected. Results: Our study showed a hepatitis A seroprevalence of 9.1% in the enrolled population. A statistically significant difference in the prevalence of anti-HAV was found between Italian and non-Italian subjects. About half of the population having anti-HAV antibodies was reported to be vaccinated, and no cases of hepatitis A were found. Conclusions: The data from our study confirmed Tuscany as an area with low HAV endemicity and showed that hepatitis A seroprevalence is significantly higher in foreign children and adolescents. The presence of more seropositive subjects than those vaccinated was probably due to a natural immunization achieved through a subclinical infection and/or to underreporting of the surveillance systems.

Vaccination rates and determinants of nine recommended vaccines among migrants in China: a nationwide cross-sectional study

In the past 70 years, in order to strengthen disease prevention and improve people's health, China had introduced a series of vaccine policies. However, compared with the permanent population, studies on the vaccination situation of the migrants were lacking. This study aimed to evaluate the vaccination rates of nine recommended vaccines (HepB, HepA, FIn, DTaP, JE, Rab, MPSV, HF, and TIG vaccine) among migrants and related determinants. We used nationwide data from the 2017 Migrant Population Dynamic Monitoring Survey (MDMS) to analyze the vaccination rates of migrants in terms of gender, age, marital status, household registration, education, health level, etc. The total vaccination rate of nine recommended vaccines was 64.8% (6488/10013). Education level and health level were positively correlated with vaccination rates, but age was negatively correlated with vaccination rates. Migrants from urban regions had a higher vaccination rate than those from rural regions. Among the nine recommended vaccines, HepB vaccination rate was the highest (59.08%), while HF vaccination rate was the lowest (4.08%). Combined with policies and demographic characteristics, the relationship between age, household registration, health level, education level and vaccination were studied. The findings suggested that more attention should be given to vaccination of migrants, and the monitoring of vaccination of such groups should be strengthened through information technology.

Role of vaccine science diplomacy in low-middle-income countries for eradicating the vaccine-preventable diseases: Targeting the "LAST MILE"

The meaning of "vaccine diplomacy (VD)" is defined as "the use of vaccines to increase a country's diplomatic relations and influence over other nations." The golden era of vaccine science diplomacy started during the time of Cold War between the United States (US) and the Union of Soviet Socialist Republics (USSR) with the development of a prototype of oral polio vaccine by the US Scientist Dr Albert Sabin working along with his Soviet counterparts. The foundation stone was already laid down by Edward Jenner when he shared his technique of the smallpox vaccine with other major countries to curb the spread of smallpox. Eventually, such a step led to the eradication of such a deadly disease. Only time has changed, not the tide. Even today, vaccines continue to remain as one of the important tools for achieving Millennium Developmental Goals (MDGs) and other targets in developing countries like India. During the wake of the Corona Virus Diseases-19 (COVID-19) pandemic, India's role in developing its vaccine science diplomacy has been a point of attraction. The phase-3 trial of Covaxin being developed by Bharat Biotech started in Lucknow and Gorakhpur in October 2020, and it is widely considered as the forerunner for the Indian vaccine market. As per the Union Health Ministry of India- "The Union Government is working on at least five distinct ways, ranging from free vaccines to guaranteed supply, in which it can help its immediate neighbours and countries in West Asia, Africa and even Latin America-officials familiar with the plan said on conditions of anonymity. The idea is to leverage the country's standing as the world's vaccine factory to merge diplomatic ties. Historically, it is observed that by the development and introduction of newer vaccines from time to time, many dismaying hurdles to vaccine science diplomacy (VSD) arise from ongoing wars and political instability. The current scenario is that both VSD and VD are at crossroads, and there is a possibility of getting a good direction if we make a piggyback policy approach of vaccine diplomacy along with the foreign policy. The lessons learned from the past must be followed now and, in the future, to make a better world for all. We acknowledge that the COVID-19 episode has again highlighted the dire need for VSD, and we assume that not only COVID-19 but in future, emerging and re-emerging diseases will occur so we have to prepare ourselves for combatting those future emerging and re-emerging diseases.

Economic evaluations of hepatitis A vaccination in middle-income countries

Economic evaluations of hepatitis A vaccination are important to assist national and international policy makers in different jurisdictions on making effective decisions. Up to now, a comprehensive review of the potential health and economic benefits on hepatitis A vaccination in middle-income countries (MICs) has not been performed yet. In this study, we reviewed the literature on the cost-effectiveness of hepatitis A vaccination in MICs. Most of the studies confirmed that hepatitis A vaccination was cost effective or even cost saving under certain conditions. We found that vaccine price, medical costs, incidence and discount rate were the most influential parameters on the sensitivity analyses. Vaccine price has been shown as a barrier for MICs in implementing universal vaccination of hepatitis A. Given their relatively limited financial resources, implementation of single-dose vaccination could be considered. Despite our findings, we argue that further economic evaluations in MICs are still required in the near future.

Declining incidence of hepatitis A in Amsterdam (The Netherlands), 1996-2011: second generation migrants still an important risk group for virus importation

BACKGROUND

The Netherlands is a very low endemic country for hepatitis A virus infections (HAV, notification rate of <1/100,000). Historically in Amsterdam, a large proportion of infections are imported from Turkey and Morocco in children returning from summer holiday. Annually since 1998, the public health service of Amsterdam has targeted these children for HAV vaccination before the summer. As the population of non-western immigrants and their descendents increases, we describe recent trends in HAV in ethnic groups in Amsterdam (1996-2011), identifying current risk groups and recommending targeted prevention through vaccination.

METHODS

We studied all cases of (non-homosexually acquired) HAV infection notified in the Amsterdam region (1996-2011, n=819) by ethnic group and generation (first/second generation migrants: FGM and SGM respectively). Incidence rates were estimated as the average number of cases per 100,000/year. Using Poisson regression, we calculated incidence rate ratios (IRR) by ethnic group and generation adjusted for age and calendar year, and modeled seasonal variation using a smoothed time series.

RESULTS

Incidence of HAV in Amsterdam dropped from 24.8/100,000 population in 1996 (178 cases) to 1.0/100,000 in 2011 (8 cases). Since 2005, 56% of cases are imported, the majority (62%) in second generation migrant (SGM) children of Moroccan, or other non-western ethnic backgrounds. The adjusted IRR in SGM relative to the ethnic Dutch population was 3.7 (95% CI: 2.3-6.1) in Moroccan SGM, 4.3 (95%CI: 2.6-7.2) in SGM of other non-western backgrounds and 1.9 (95%CI: 0.8-4.1) in Turkish SGM.

CONCLUSION

Though incidence of HAV in Amsterdam has declined substantially since 1996, it is still higher in SGM children of Moroccan & other non-western ethnic backgrounds. In line with WHO recommendations of June 2012, introduction of single-dose HAV vaccination, targeted at SGM children from HAV endemic countries, could be considered within the routine childhood vaccination schedule.

[Anti-hepatitis A virus seropositivity in children of immigrant parents living in France and vaccination recommendations]

The hepatitis A-seropositivity rate for children born in France is very low: 0 of 81 born to two French-born parents and 5 of 126 (4 %) infants for whom at least one parent was born in an endemic area. In contrast, the rate was high (28.8 %, 17/59) for children born in an endemic area. Hence, recommendations to vaccinate children who could be exposed during overseas trips to visit family or by visiting family members coming from endemic areas are fully justified.

Hepatitis A outbreaks: the effect of a mass vaccination programme

A Hepatitis A vaccination programme of people belonging to risk groups begun in Catalonia in 1995 and a universal vaccination programme of pre-adolescents 12 years of age with the hepatitis A + B vaccine was added in 1998. The aim of the study was to investigate the characteristics of hepatitis A outbreaks occurring in Catalonia between 1991 and 2007 to determine the associated risk factors and optimize the use of vaccination. Incidence rates of outbreaks, cases and hospitalizations associated with outbreaks and the rate ratios (RR) of person-to-person transmission outbreaks between the periods before and after mass vaccination and their 95% confidence intervals (CI) were calculated. A rate of 2.45 outbreaks per million persons per year was found. The rate of cases affected in these outbreaks was 1.28 per 10(5) persons per year and the rate of hospitalizations was 0.45 per million persons per year. In person-to-person outbreaks, the highest incidence rate (5.26 and 6.33 per million persons per year) of outbreaks according to the age of the index case was in the 5 to 14 year age group in both periods (RR:0.83; 95% CI:0.48-1.43). A significant increase was observed in the 25 to 44 year age group (RR: 0.35; 95% CI 0.14-0.77). Hepatitis A vaccination has made an important impact on burden and characteristics of outbreaks and could provide greater benefits to the community if the vaccine was administrated to children during their first years of life.

Epidemiology of hepatitis A virus infections, Germany, 2007-2008

Communicating vaccination recommendations may help reduce infections.

[Indication of determination of antibodies against hepatitis C and A viruses in the protocol for the care of young immigrants]

OBJECTIVES

To evaluate systematic determination of antibodies against hepatitis C virus (HCV) and hepatitis A virus (HAV) within the protocols for the care of young immigrants (PCYI).

METHODS

We performed a descriptive, cross-sectional, multicenter study. Antibodies against HCV and HAV were determined in children aged from 6 months to 15 years from low-income countries who had immigrated to Spain less than 12 months previously. Age, sex and country of origin were registered. The cost of vaccinating all immigrant children (with the HA vaccine and HA-HB vaccine, public health price and retail price) without screening was compared with that of vaccinating non-immune children only.

RESULTS

HCV antibodies were determined in 1055 children and only one was positive [0.09% (95% CI: 0-0.53%)]. HAV antibodies were determined in 992 children and, overall, 38% were positive (95% CI: 35.0-41.1). Distribution by country of origin was as follows: Central and South America (n=352) 34.9%, Maghreb (n=246) 44.7%, and India, Pakistan and Bangladesh (n=162) 58.6%. According to the children's age, country of origin, and the price of the vaccine used, HAV antibody determination in young immigrants before HAV vaccination is efficient.

CONCLUSIONS

Because of the low prevalence of HCV antibodies in the pediatric immigrant population, systematic determination is not warranted. Evaluating HAV antibodies in each immigrant child could increase the efficiency of PCYI.

Trends in hepatitis A, B, and shigellosis compared with gonorrhea and syphilis in men who have sex with men in Amsterdam, 1992-2006

BACKGROUND

Since the mid-1990s, sexually transmitted infections (STIs) among men who have sex with men (MSM) have increased and appear to be related to more risky sexual behavior. We compare trends in hepatitis A, acute hepatitis B, and shigellosis with the trends of gonorrhea and infectious syphilis in Amsterdam MSM more than a period of 15 years.

METHODS

We used data of all reported hepatitis A, acute hepatitis B, and shigellosis, and from all patients newly diagnosed with gonorrhea and infectious syphilis who visited the Public Health Service STI outpatient department in Amsterdam between January 1, 1992 and December 31, 2006.

RESULTS

Hepatitis A incidence remained unchanged in MSM (mean 0.97 per 1000 MSM, range 0.04-2.27), who had 21% of all 1697 infections. Hepatitis B likewise remained unchanged in MSM (mean 0.47 per 1000 MSM, range 0.19-0.77), who had 41% of all 448 infections. Most shigellosis is travel-related (657/974), and 16% of the infections occurred in MSM. Its incidence dropped in general, but not in MSM. Both gonorrhea and infectious syphilis in MSM show a steep increase, mainly after 1998.

DISCUSSION

Hepatitis A, B, and shigellosis do not follow the rising trends of conventional STI in MSM, which are believed to result from increased risky sexual behavior. This disparity in trends implies differences in transmission dynamics. Recent molecular epidemiologic studies suggest that clustered transmission in social MSM networks plays a major role.

Differences in hepatitis A seroprevalence among geographical regions in Turkey: a need for regional vaccination recommendations

Hepatitis A is a worldwide vaccine-preventable infection. Recommendation of vaccination depends on the endemicity of the disease. The World Health Organization recommends universal hepatitis A vaccination in intermediate areas; however, there is no need of mass vaccination in high and low endemicity regions. Therefore, most of the countries are using a vaccination policy according to the endemicity characteristic representing the whole of the country. The endemicity of this infection varies due to sanitary and hygiene conditions and socioeconomic differences among the countries and in various regions of the same country. A sample of 1173 persons between the age of 0 and 91 years from nine randomly selected medical centres from five different geographical centres of Turkey were tested for the level of anti-hepatitis A virus (anti-HAV) immunoglobulin-G antibodies using an enzyme-linked immunosorbent assay. The overall prevalence of anti-HAV antibodies was 64.4% (1142/1173). While the rate of sero-positivity was over 80% in the 5-9 age group and more than 90% after 14 years of age in south-eastern and eastern regions, it was lower than 50% at the age of 5-9 years in central and western regions and remains under 80% in those areas. We conclude that the differences observed in HAV sero-positivity among various geographical regions in Turkey support a universal HAV immunization policy for children currently living in regions of intermediate endemicity.

Long-term trends in hepatitis A incidence following the inclusion of Hepatitis A vaccine in the routine nationwide immunization program

For many years hepatitis A was one of the most common vaccine preventable diseases in Israel. In 1999, Israel became the first country to introduce an inactivated hepatitis A vaccine into its national childhood vaccination program. The objectives of the present study were to study trends in disease incidence after the implementation of the new vaccination policy and to assess vaccination coverage among children and adults in Israel. We used the databases of the second largest HMO in Israel (1.7 million members) to identify patients who had evidence of hepatitis A in 1998 and 2007 and to collect information on all subjects who received at least one dose of hepatitis A vaccine during the study period. Hepatitis A vaccination coverage in children <5 years and 5-14 years of age increased from 9% and 15% in 1998 to 89% and 68% in 2007, respectively. During this period the annual incidence of hepatitis A dropped from 142.4 per to 7.6 per 100 000. The most prominent reduction in the age-specific annual incidence rates was calculated in children <5 years from 239.4 per 100 000 in 1998 to 2.2 per 100 000 in 2007 and from 310.3 per 100 000 to 3.0 per 100 000 in children aged 5-14 years. In endemic areas, vaccination of infants and children against hepatitis A can greatly reduce the total burden of the disease.

The shifting epidemiology of hepatitis A following routine childhood immunization program in Israel

OBJECTIVES

In 1999 Israel became the first country to introduce immunization against hepatitis A to its national childhood vaccination program. The study objectives were to assess the uptake of hepatitis A vaccine following the new policy and to examine the incidence of hepatitis A and the number of prevented cases.

METHODS

Data on incidence of hepatitis A and vaccination rates were obtained from a large health maintenance organization in Israel covering 1.6 million members. We identified all members that were diagnosed by a primary care physician as suffering from hepatitis A, had a positive hepatitis A virus-IgM test result, or were hospitalized due to hepatitis A between 1998 and 2004.

RESULTS

The results indicate that 5 years following its inclusion in the national childhood immunization program, vaccination coverage levels with at least one dose of hepatitis A vaccine for children aged under 5 years and 5-14 years were 87% and 51%, respectively. During this period the annual incidence rates declined by 88% from 142.4 to 17.3 per 100,000. The most significant reduction in morbidity was observed among children.

CONCLUSIONS

In endemic areas, vaccination of infants and children against hepatitis A may be efficient to greatly reduce the total burden of the disease.

Different transmission patterns of hepatitis A virus for two main risk groups as evidenced by molecular cluster analysis

Men who have sex with men and traveling children are the most important risk groups for transmission of hepatitis A virus (HAV) in Amsterdam, The Netherlands. Between these two risk groups, different HAV genotypes are found. In this study the patterns of introduction and transmission of HAV were investigated in the two groups. HAV sequences from Amsterdam patients were divided according to risk: (I) travelers and their contacts, (II) homosexual men and their contacts. The sequences in each risk group were then grouped into clusters based on the genetic distances between the sequences. Among travelers many sporadic cases were found, the clusters were small, and introduced frequently into the population, mostly in the second half of each calendar year, indicating a seasonal pattern of introduction and transmission after the summer holidays. Among men who have sex with men the clusters were bigger and remained present for a longer time; sporadic cases were few, and introduction of new strains occurred only occasionally but throughout the year. Our findings indicate that new HAV strains are frequently imported into Amsterdam by travelers, but they are limited in the extent and season of their spread. In contrast, HAV is only occasionally imported into the male homosexual and bisexual population, but remains endemic and spreads to a large number of individuals without a seasonal pattern.