Mass vaccination against hepatitis B in infants in Italy

Long-term immune protection against HBV: associated factors and determinants

In Italy, vaccination against hepatitis B became compulsory for all the newborns and 12-years-old adolescents in 1991. The main purpose of this study was to evaluate the persistence of long-term protection against HBV in medical students of the University of L’Aquila and in postgraduates Medical Doctors (HCWs) working in San Salvatore Hospital. The second aim was to study the variables associated with a protective anti-HBs antibody level, such as age at vaccination, gender, time elapsed from the last dose of vaccination.

Three hundred and forty-two subjects were enrolled from January 2017 to January 2019 and a blood sample was collected to evaluate the levels of serum HBsAg, anti-HBs and anti-HBc. Statistical analysis calculated a multivariable logistic regression model to examine predictors of a protective anti-HBs titer. The larger part (239, 70%) of the students had an anti-HBs titer >10 mIU/mL, those were statistically significant older (26.7 vs 24.5 years, p < .001), vaccinated at age 12 years (83.5% vs 59.9% among vaccinate at infancy, p < .001) and more frequently attending postgraduate medical school (80.8% vs 57.5% among healthcare profession school, p < .001). The multivariable logistic regression model showed that HBV vaccination at age of 12 was significantly and independently associated with protective titers (OR = 10.27, p = .019).

The results agreed with literature on HBV vaccination, confirming the efficacy of vaccination after 20 years. In particular, our results suggest that adolescent administration is the main predictor of a protective title, regardless of gender, course and years since vaccinations.

Persistence of protective anti-HBs antibody levels and anamnestic response to HBV booster vaccination: A cross-sectional study among healthcare students 20 years following the universal immunization campaign in Italy

Vaccination against Hepatitis B Virus (HBV) became mandatory in Italy for all newborns and 12 years-old individuals in the 1991. The immunogenicity of HBV vaccine and the effectiveness of the universal immunization strategy have been widely demonstrated. However the need to assess the antibody concentrations above the well known serological correlate of protection for HBV infection (≥10 mIU/mL), established in individuals immunized with a 3 doses vaccination course, is still recommended in subjects exposed to occupational risks in different settings, particularly the healthcare services. This practice has to be performed during the preventive medical examination, before the worker's exposure to biological hazards, as a fundamental part of Occupational Health Surveillance Programs in several Countries, including Italy: the goal is to assure individual protection, also providing booster doses when needed, after many years following the primary vaccination. During the 2011–2013 period, an observational study was performed in Healthcare students (HCSs) trained at a regional university acute-care hospital in North-Western Italy, properly immunized against HBV during infancy or adolescence, in order to evaluate the persistence of seroprotection and to assess the anamnestic response to booster vaccination. Data from 717 subjects undergoing HbsAg Ab and HBc Ab testing during the preventive medical examination, and receiving a booster dose of HBV vaccine when resulting with a non-protective titer (<10 mIU/mL), were collected and analyzed. Most of the HCSs (74.6%) included in the survey, mean age 24.8 y ( ± 4.6 SD), had received the primary vaccination course during the first year of life (3–5–11 months). Globally, 507 (70.7%) HCSs showed protective antibody titres, and an anamnestic response was observed in more than 95% subjects receiving the booster dose. Our study demonstrated the long-term persistence of protection of HBV vaccine, more than 20 y following the primary immunization, in HCSs who are exposed to occupational health risk. The anamnestic response observed in non-seroprotected subjects who received the booster further confirms the capability of the HBV vaccine to create a strong immunological memory.

Acute Hepatitis B After the Implementation of Universal Vaccination in Italy: Results From 22 Years of Surveillance (1993-2014)

BACKGROUND

Hepatitis B vaccination has proven to be very safe and highly effective. This study assessed the proportion of successfully vaccinated individuals among cases with acute hepatitis B, the proportion of preventable cases if individuals were vaccinated as recommended, and the reasons for failures.

METHODS

We analyzed data reported to the Italian Surveillance System for Acute Viral Hepatitis from 1993 to 2014.

RESULTS

A total of 362 of 11 311 (3.2%) cases with acute hepatitis B were vaccinated. Of the 277 cases for whom immunization data were available, 50 (18%) received a complete vaccination course according to the correct schedule and before exposure to hepatitis B virus. Molecular characterization of 17 of these cases showed that 6 were infected with S-gene mutants. Among the 10 949 unvaccinated cases, 213 (1.9%) escaped mandatory vaccination and 2821 (25.8%) were not vaccinated despite being at increased risk of infection. Among the latter, the most common risk factors were cohabitation with hepatitis B surface antigen (HBsAg) carriers, intravenous drug use, and homosexual/bisexual practices. Thirty-seven percent of the unvaccinated households with HBsAg carriers were aware of their risk. Lack of trust in the vaccination, negative attitude, and inaccurate beliefs followed by lack of or poor communication and low perceived severity of the disease were the most frequent reasons for vaccine hesitancy.

CONCLUSIONS

Development of acute disease in successfully vaccinated individuals is a rare event. Further efforts are needed to enhance the vaccine coverage rate in individuals at increased risk of infection.

The long-term immunogenicity of recombinant hepatitis B virus (HBV) vaccine: contribution of universal HBV vaccination in Italy

Background

Universal hepatitis B virus (HBV) vaccination of newborn babies was introduced in Italy in 1991 and was extended to 12-years-old children for the first 12 years of application so as to cover in a dozen years the Italian population aged 0-24 years. The aim of this study was to identify factors associated with long-term immunogenicity against HBV 17 years after primary vaccination in students attending medical schools in Naples, Italy.

Methods

1,704 students attending the school of medicine, schools of the healthcare professions, or postgraduate medical schools of the Second University of Naples, Italy, from September 2012 to December 2013 were enrolled in this study. Of these, 588 had been vaccinated against HBV in infancy and 1,116 when 12 years old. Multivariate logistic regression analysis was used to identify factors associated with the level of long-term immunogenicity.

Results

All vaccinated subjects were HBsAg/anti-HBc negative: 270 (15.8%) had an anti-HBs titer between 1 and 9 IU/L, 987 (57.9%) between 10 and 400 IU/L, and 447 (26.3%) over 400 IU/L. When compared with the latter two subgroups, those with anti-HBs titers lower than 10 IU/L were younger (24 ± 5.2 years vs. 26 ± 4.9 years, p < 0.000), more frequently students attending a healthcare school (59% vs. 47%, p < 0.001), and more frequently had been vaccinated in infancy (50% vs. 31.5%, p < 0.0001). Multivariate logistic regression identified age at vaccination as the only factor independently associated with an anti-HBs titer <10 IU/L (OR: 2.43; C.I. 95%: 1.57–3.76, p = 0.001).

Conclusions

Universal HBV vaccination in Italy has been more effective in generating a prolonged protective response in subjects vaccinated at adolescence than in infancy. Students with a low anti-HBs titer should be considered for a booster dose because most will be exposed to the risk of acquiring HBV for decades.

Prevention of hepatitis B virus infection: from the past to the future

About 3-5 % of the world's population is chronically infected by hepatitis B virus (HBV) and is at risk of developing liver cirrhosis or hepatocellular carcinoma. The risk of dying prematurely because of chronic HBV infection is higher in younger people. The current strategies to prevent HBV infection involve immunization (active and/or passive) and antiviral chemoprophylaxis. The vaccines available for active immunization, containing hepatitis B surface antigen, are safe and confer long-term immunity in most healthy subjects. Since the vaccination is unsatisfactory in some patients, e.g., those with chronic kidney disease, human immunodeficiency virus infection, type I diabetes mellitus, and celiac disease, new strategies of vaccination are required. The neonatal, infant, and adolescent routine program vaccination in about 180 countries has greatly decreased the disease burden. Passive immunization with specific HBV immunoglobulins is recommended after single acute exposure, in infants born to infected mothers, and in HBV-infected patients undergoing liver transplantation combined with nucleoside/nucleotide analogues (chemoprophylaxis). Chemoprophylaxis is also indicated in HBV carrier candidates for immunosuppressive treatment and in patients with occult B infection undergoing immunosuppressive therapy or hematopoietic stem cell transplantation. Since HBV is not eradicable by an immune response or by antiviral drugs developed so far, the only preventive strategy remains global neonatal vaccination in all countries, firstly in HBV-endemic countries.

Prevention of hepatocellular carcinoma: beyond hepatitis B vaccination

Chronic hepatitis B (CHB) infection is the major cause of hepatocellular carcinoma (HCC), accounting for approximately 50% of the underlying etiologies. We reviewed the primary, secondary, and tertiary measures for the prevention of hepatitis B virus (HBV)-related HCC. The most effective method for preventing HBV-related HCC is vaccination. Universal hepatitis B vaccination has been shown to reduce the rates of HBV infection and HCC significantly. Once chronic HBV infection is established, antiviral treatment using interferon or nucleos(t)ide analogs is used to prevent disease progression to cirrhosis, HCC, or both. Studies have found viral replication indicated by HBV DNA level to be a strong risk factor for development of HCC. Additionally, periodic surveillance using ultrasonography and serum α-fetoprotein for earlier detection of HCC is also important so that curative treatments with survival benefit can be possible. Finally, adjuvant antiviral treatment using interferon or nucleos(t)ide analogs is used to prevent tumor recurrence after curative resection. Adjuvant interferon treatment prevented early recurrence, not late recurrence, probably due to its antiangiogenetic and antiproliferative effects. Adjuvant nucleos(t)ide analogs demonstrated promising results for preventing late recurrence, probably due to effective suppression of viral replication. Further investigations are required to establish the optimal preventive plans for HBV-related HCC.

Hepatitis B immunity in teenagers vaccinated as infants: an Italian 17-year follow-up study

We assessed the persistence of hepatitis B surface antigen antibody (anti-HBs) and immune memory in a cohort of 571 teenagers vaccinated against hepatitis B as infants, 17 years earlier. Vaccinees were followed-up in 2003 and in 2010 (i.e. 10 years and 17 years after primary vaccination, respectively). When tested in 2003, 199 vaccinees (group A) had anti-HBs <10 mIU/mL and were boosted, 372 (group B) were not boosted because they had anti-HBs ≥10 mIU/mL (n = 344) or refused booster (n = 28) despite anti-HBs <10 mIU/mL. In 2010, 72.9% (416/571) of participants had anti-HBs ≥10 mIU/mL (67.3% in group A vs. 75.8% in group B; p 0.03). The geometric mean concentrations (GMCs) were similar in both groups. Between 2003 and 2010, anti-HBs concentrations in previously boosted individuals markedly declined with GMC dropping from 486 to 27.7 mIU/mL (p <0.001). Fifteen vaccinees showed a marked increase of antibody, possibly due to natural booster. In 2010, 96 individuals (37 of group A and 59 of group B) with anti-HBs <10 mIU/mL were boosted; all vaccinees of the former group and all but two of the latter had an anamnestic response. Post-booster GMC was higher in group B (895.6 vs. 492.2 mIU/mL; p 0.039). This finding shows that the immune memory for HBsAg persists beyond the time at which anti-HBs disappears, conferring long-term protection.

Twenty years of universal vaccination against hepatitis B in Italy: achievements and challenges

Viral hepatitis B is a vaccine-preventable disease. Vaccination has proved to be safe and highly effective in reducing the incidence, the carrier rate and HBV-related mortality on a global scale. In Italy, universal vaccination against hepatitis B started in 1991 in infants as well as in adolescents, providing an outstanding record of safety and effectiveness. Within a few years, over 95% coverage was consistently reported. Today, some 17 million people are immune against hepatitis B and their immunity has been shown to be long-lasting. At present, no booster is required in healthy vaccinated people to sustain protection. Surveillance data from Italy have shown a clear overall decline in hepatitis B among successfully vaccinated individuals. Furthermore, a generation of children and young people (at present cohorts ranging from 0 to 32 years) is emerging with practically no markers of HBV infection. Italy’s vaccination programme has resulted in substantial progress towards the prevention and control of hepatitis B. The vaccination programme must continue. Maintaining mandatory vaccination of infants and increasing HBV vaccination coverage in high-risk groups, including households of HBsAg carriers as well as immigrants, remain a priority for the future.

The worldwide impact of vaccination on the control and protection of viral hepatitis B

Viral hepatitis B is a leading cause of acute and chronic liver disease worldwide, including cirrhosis and hepatocellular carcinoma. Vaccination is the most effective measure for controlling and preventing hepatitis B and its severe long-term sequelae. According to the World Health Organization (WHO), by the end of 2008 177 countries had introduced hepatitis B vaccination into their national routine neonatal, infant and/or adolescent immunisation programmes, and Italy was one of the first countries to implement a universal strategy of hepatitis B vaccination. The implementation of such vaccination programmes has globally resulted in a marked decrease in disease burden, in the carrier rate and in hepatitis B-related morbidity and mortality. Despite this success, work remains to be done to fully achieve the WHO goal of control of hepatitis B and HBV-related diseases on a global scale.

The global impact of vaccination against hepatitis B: a historical overview

Hepatitis B virus (HBV) infection is a world wide public health problem of major concern. HBV infection may lead to chronic liver disease, including cirrhosis and hepatocellular carcinoma (HCC). Vaccination is the most effective measure to control and prevent hepatitis B and its long-term serious sequelae on global scale, both in terms of cost-effectiveness and benefit-cost ratios. According to the WHO recommendations, universal vaccination has been currently implemented in 168 countries world wide with an outstanding record of safety and efficacy. The effective implementation of such programmes of vaccination has resulted in a substantial decrease in disease burden, in the carrier rate and in hepatitis B-related morbidity and mortality. A future challenge is to overcome the social and economic hurdles which still hamper the introduction of hepatitis B vaccination on a global scale.

Impact of hepatitis B vaccination in a highly endemic area of south Italy and long-term duration of anti-HBs antibody in two cohorts of vaccinated individuals

The aims of this study were to evaluate the impact of hepatitis B vaccination on the changing pattern of HBV infection in a former hyperendemic area (Afragola, South Italy), and to assess the long-term persistence of anti-HBs in two cohorts of individuals vaccinated as infants 18 and 23 years ago. Our data shows a significant decline in the prevalence of hepatitis B virus (HBV) markers in the general population from 1978 to 2006 (HBsAg: 13.4% versus 0.91%; anti-HBc: 66.9% versus 7.6%; p<0.001). Data from two cohorts of vaccinees provides further evidence regarding the long-term persistence of vaccine-induced anti-HBs. Data here reported indicates that the implementation of vaccination had a great impact in the control and prevention of hepatitis B in Italy.

Changing patterns of hepatitis B infection in Italy and NAT testing for improving the safety of blood supply

In Italy, as in most industrialized countries, the burden of hepatitis B has progressively declined in recent decades as a consequence of general improvements in hygiene and standard of living, the introduction of several public health measures, refinement in blood screening and the implementation of specific vaccination programmes. Universal hepatitis B vaccination for all infants and adolescents as well as individuals at increased risk has resulted in considerable progress towards prevention and control of HBV infection. The residual risk of transmitting blood-borne viruses through transfusion is currently very low. Nucleic acid testing can shorten the window period and, consequently, further reduce the risk of viral transmission. Blood donor screening for HCV by NAT was initiated in Italy in 2001 and became mandatory in June 2002. NAT for HIV is currently mandatory in four regions, not mandatory but almost universally performed in another thirteen regions, and not yet introduced in the remaining four regions. NAT for HBV is currently mandatory in four regions and under evaluation in the remaining. NAT for HBV may be a useful tool in detecting acute viral infections in the window phase as well as the occult infections. Its efficacy in improving the safety of blood supply is expected to be higher in countries with intermediate/high endemicity, where anti-HBc antibody screening cannot be routinely performed. There is agreement that, at present, the implementation of HBV DNA testing will not allow for discontinuation of screening for HBsAg.

Long-term immunogenicity of hepatitis B vaccination and policy for booster: an Italian multicentre study

BACKGROUND

Universal anti-hepatitis-B vaccination of infants and adolescents was implemented in Italy in 1991. We undertook a multicentre study in previously vaccinated individuals to assess the duration of immunity and need for booster, over 10 years after vaccination.

METHODS

In 1212 children and 446 Italian Air Force recruits vaccinated as infants and adolescents, respectively, we measured the concentrations of antibodies to hepatitis-B surface antigen (anti-HBs) and the presence of antibodies to hepatitis-B core antigen (anti-HBc) at enrollment; postimmunisation values were not available. Individuals positive for anti-HBc were tested for hepatitis B surface antigen (HBsAg) and hepatitis B viral DNA. Individuals with anti-HBs concentrations at 10 IU/L or more were regarded as protected; those with antibody less than 10 IU/L were given a booster dose and retested 2 weeks later. Individuals showing postbooster anti-HBs concentrations of less than 10 IU/L were offered two additional vaccine doses and retested 1 month after the third dose.

FINDINGS

Protective anti-HBs concentrations were retained in 779 (64%, 95% CI 61.6-67) children and 398 (89%, 86.4-92.1) recruits. We recorded antibody amounts of less than 10 IU/L in 433 children (36%, 33-38.4) and 48 (11%, 7.9-13.6) recruits. One child and four recruits were positive for anti-HBc, but negative for HBsAg and hepatitis B viral DNA. Antibody concentrations were higher in recruits than in children (geometric mean titre 234.8 IU/L vs 32.1 IU/L, p=0.0001). 332 (97%) of 342 children and 46 (96%) of 48 recruits who received a booster showed an anamnestic response, whereas ten (3%) children and two (4%) recruits remained negative for anti-HBs or had antibody concentrations of less than 10 IU/L. Prebooster and postbooster antibody titres were strongly correlated with each other in both groups. All individuals given two additional vaccine doses (eight children and two recruits) showed anti-HBs amounts of more than 10 IU/L at 1 month after vaccination.

INTERPRETATION

Strong immunological memory persists more than 10 years after immunisation of infants and adolescents with a primary course of vaccination. Booster doses of vaccine do not seem necessary to ensure long-term protection.

Hypertransaminasemia in childhood as a marker of genetic liver disorders

BACKGROUND

The widespread use of routine biochemical assays has led to increased incidental findings of hypertransaminasemia. We aimed to evaluate the prevalence of different causes of raised aminotransferase levels in children referred to a university department of pediatrics.

METHODS

We investigated 425 consecutive children (age range, 1-18 years) with isolated hypertransaminasemia. All patients had raised aminotransferase levels on at least two occasions in the last month before observation. Cases due to major hepatotropic viruses were excluded.

RESULTS

During the first 6 months of observation, 259 children showed normalized liver enzymes. Among the remaining 166 patients with hypertransaminasemia lasting for more than 6 months, 75 had obesity-related liver disease; 51, genetic disorders; 7, autoimmune hepatitis; 5, cholelithiasis; 3, choledochal cyst; and 3, celiac disease. Among the 51 children with genetic disorders, 18 had Wilson disease; 14, muscular dystrophy; 4, alpha-1-antitrypsin deficiency; 4, Alagille syndrome; 4, hereditary fructose intolerance; 3, glycogen storage disease (glycogenosis IX); 2, ornithine transcarbamylase deficiency; and 2, Shwachman's syndrome. In 22 children, the hypertransaminasemia persisted for more than 6 months in the absence of a known cause.

CONCLUSIONS

Genetic disease accounted for 12% of cases of isolated hypertransaminasemia observed in a tertiary pediatric department. A high level of suspicion is desirable for an early diagnosis of these disorders, which may present with isolated hypertransaminasemia and absence of typical clinical signs.

Persistence of anti-HBs 5 years after the introduction of routine infant and adolescent vaccination in Italy

A population survey was conducted to assess the duration of anti-HBs levels > 10 IU/l in vaccinees living in Lazio Region (Italy) 5 years after the introduction (15 June 1991) of compulsory vaccination of new-borns and 11-year-old children. A random sample of 1192 (533 children born in 1991--92 and 659 adolescents born in 1979--81) was selected. In 92.9% of children and 94.1% of adolescents anti-HBs titres were protective (> or = 10 IU/l). These subjects with protective titres were divided into three categories: low responders (anti-HBs titres = 10--500 IU/l), medium responders (anti-HBs titres = 501--2000 IU/l) and high responders (anti-HBs titres > 2000 IU/l). Factors associated with the level of response were analysed, using a multiple politomic logistic regression analysis. Greater age at first dose (11--12 years) was associated with higher titres (OR = 2.1, 95% CI = 1.4--3.2 for medium responders and OR = 3.0, 95% CI = 1.9--4.8 for high responders). Simultaneous administration of DT vaccine was associated with lower titres (OR = 0.4, 95% CI = 0.2-0.8 for medium responders and OR = 0.3, 95% CI = 0.1--0.7 for high responders).

Update on hepatitis B vaccination in Italy 10 years after its implementation

Since the beginning of the Italian program of immunization against hepatitis B, vaccine has been given to more than 9 million children, with an outstanding record of safety and efficacy. The coverage rate is globally around 94%, with differences between Northern and Southern regions, the latter having the lower acceptance rate. According to the National Surveillance System (SEIEVA), the incidence of acute hepatitis B per10(5) inhabitants declined from 5.4 in 1990 to 2.9 in 1998. The reduction was even greater among 15-24-year-old individuals, where the incidence rate per 10(5) decreased from 17.3 to 4.2 in the same period. In parallel with the decline of hepatitis B, Delta hepatitis has also dropped significantly. We expect that by the year 2003 (12 years after the beginning of the program) this vaccination strategy will have led to the protection of all Italians aged 0-24 years, who are those at the higher risk for acquiring hepatitis B virus (HBV) and for developing the chronic carrier state.

Safety and immunogenicity of hepatitis A vaccine in infants: a candidate for inclusion in the childhood vaccination programme

Forty-eight infants received a single dose (720 ELISA units = 0.5 ml) of inactivated hepatitis A vaccine at the fifth month of age with booster at the 11th month of age, together with the second and third doses of the vaccines compulsory under Italian law (diphtheria, tetanus, oral polio and hepatitis B). Overall, the seroconversion rate was 100%. The anti-HAV geometric mean titre (GMT) reached 3,021 mIU/ml in infants born to anti-HAV-negative mothers, but only 399 mIU/ml in infants born to anti-HAV-positive mothers. Hepatitis A vaccine was immunogenic, safe and well tolerated without significant side-effects. There seems to be no reason for not including it in childhood vaccination programmes particularly in low endemic HAV areas.

Safety and immunogenicity of a combined diphtheria-tetanus-acellular pertussis-hepatitis B vaccine administered according to two different primary vaccination schedules. Multicenter Working Group

The reactogenicity and immunogenicity of a tetravalent diphtheria-tetanus-acellular pertussis-hepatitis B (DTPa-HB) vaccine (SmithKline Beecham) were studied in 565 infants immunized according to one of two different schedules, at 2, 4 and 6 months of age (group A n = 208) or at 3, 5 and 11 months of age (group B n = 357). The incidences of local and general reactions within the first 8 days after vaccination were similar in the two groups of infants, the vast majority being mild in intensity and occurring within 2-3 days of vaccine administration. Severe local symptoms were rare: pain after 0.6% of all doses, redness after 0.5% and 1.3%, and swelling after 0.3% and 1.5%, in group A and B, respectively. Only one infant in group A and one in group B had a temperature > 39.0 degrees C. Both schedules proved satisfactory in obtaining high levels of antibodies against all antigens. The rates of serologic response against the different antigens reached 100% in both groups. Antibody titres against all vaccine components were elevated following both schedules, but after the third dose of vaccine geometric mean antibody titres (GMTs) against D toxoid, filamentous haemagglutinin (FHA), pertactin (PRN) and hepatitis B (HB) were significantly higher in the 3, 5, 11 group than after the 2, 4, 6 schedule. Antibody titres measured at 7 months of age in the group immunized at 2, 4 and 6 months were higher than those reached at 6 months of age in infants immunized at 3, 5 and 11 months, but FHA and PRN were within the range of DTPa vaccine with proven efficacy. We conclude that DTPa-HB vaccine was safe, well tolerated and highly immunogenic. Both vaccination schedules (2, 4, 6 and 3, 5, 11) can be considered suitable for mass immunization programmes.

Hepatitis B vaccination: universal vaccination of newborn babies and children at 12 years of age versus high risk groups. A comparison in the field

From 1983 to 1993 two anti-hepatitis B vaccinal strategies were adopted in two small towns of Southern Italy at high incidence for HBV infections: Afragola (prevalence of HBsAg carriers of 13.4%) and Frattamaggiore (prevalence of HBsAg carriers of 12.9%). In Afragola, the universal vaccination of infants in their first year of life and adolescents at 12 years of age was carried out, while in Frattamaggiore the selective vaccination of high risk groups of population was introduced. During this study, the changes in the HBV infection endemicity in both towns has been tested by monitoring the incidence of new cases of viral hepatitis B and by the prevalence study of HBsAg carriers prior to and 10 years after the beginning of the immunization programme (1978-1993). The results suggest that universal vaccination of infants in the first year of life and adolescents at 12 years of age has a greater efficiency on the improvement on the endemic status of the infection in the general population in comparison with selective vaccination, when the incidence of new cases of disease and the prevalence of number of HBsAg and anti-HBc carriers in the two populations are considered.

Duration of hepatitis B antibody response in children immunised with hepatitis B and compulsory vaccines

Twenty four subjects were simultaneously administered DT toxoids, OPV and HBV vaccines at the age of 3, 4-5 and 11 months and then followed up for 2 and 4 years in order to evaluate the duration of the immune response and the need and the timing of HBV revaccination. A fall in anti-HBs titre below 10 mIU/ml was observed at the follow up in 4/24 (16.7%) of the subjects. In other 5 children (20.8%) anti-HBs titre was found to be just above 10 mIU/ml. This would suggest that a revaccination is indicated and it could be performed at the age of 5-6 years when children enter school. This schedule is simple, effective and money saving since it reduces the cost/benefit ratio and the number of visits for immunisations, and it is expected to improve the compliance for the vaccination.

Implementation in Italy of a universal vaccination programme against hepatitis B

Italy was the first industrialized country to introduce mass vaccination against hepatitis B. Following the collection of epidemiological data on age-specific incidence rates of infection, a law was issued in 1991 which established mandatory immunization of neonates and 12-year-old adolescents. This strategy will lead to the protection of all subjects aged 0-24 years within 12 years and to the elimination of circulation of hepatitis B virus (HBV) in a few decades. The first data on compliance with vaccination, both in infants and in adolescents, indicate the success of the programme, which was helped by good vaccination delivery services and awareness of the risks of hepatitis B both by physicians and the public. A multi-centre study on protective antibody level and kinetics over time is in progress. Preliminary results show an excellent response to vaccination. High-risk strategies will continue by actively offering HBV vaccination free of charge to all those exposed to infection via occupation or life-style. The Italian policy of universal vaccination against HBV can therefore be regarded as a model for the introduction of mass immunization into other countries.

Vaccination against hepatitis B: the Italian strategy

Viral hepatitis B, which is a major health problem worldwide, is endemic in Italy. In response to this, vaccination became compulsory in 1991. Vaccine is administered to neonates and 12-year-old adolescents; in 12 years time, all Italians under the age of 24 will be immune to HBV.

A pilot model of vaccination against hepatitis B virus suitable for mass vaccination campaigns in hyperendemic areas

A hepatitis B vaccination campaign was carried out in a town of 60,000 inhabitants, Afragola, Campania, Italy, a hyperendemic area for hepatitis B where HBsAg prevalence was 13.4% and anti-HBc prevalence was 64.7%. This experimental pilot project aimed to reduce the incidence of both acute and asymptomatic viral hepatitis B and of related chronic liver complications. From 1983-1989, 8,400 subjects were vaccinated: 6,900 children up to 10 years of age and 1,500 subjects from 11-60 years of age. High seroconversion rates were observed: 99.0% in all children under one year of age, 96.0% in the older children, and 86.7% in adults. The rate of infection in Afragola has diminished from 63/100,000 in 1983 to 10/100,000 in 1989. Carriers of HBsAg decreased in the general population (7.3% compared to 13.4%), especially in children up to 10 years of age (1.0% compared to 9.0%). In babies who received hepatitis B vaccine at the same time as compulsory vaccinations compliance was 98% while it was 80% in babies who were vaccinated separately. In June 1991 the Italian Parliament promulgated a decree which imposes hepatitis B vaccination for all newborn babies at 3, 5, and 11 months of age, at the same times as the mandatory childhood vaccinations (diphtheria, tetanus, and polio) according to a new protocol (Piazza scheme) which has been in use since January 1987 in our pilot vaccination campaign in Afragola.

Immune response to simultaneous administration of a recombinant DNA hepatitis B vaccine and multiple compulsory vaccines in infancy

The reactogenicity and immunogenicity of simultaneous administration of recombinant DNA hepatitis B vaccine with diphtheria and tetanus toxoids (DT) and oral poliovirus vaccine (OPV) in 111 infants were compared with those of DT and OPV alone in a control group of 21 infants. All subjects received three doses of the vaccine according to one of three different schedules of vaccination. Reactions following simultaneous administration of vaccines were all but absent, with mild pain reported for four out of 111 subjects, compared with one of 21 in the control group. Seroconversion rates of 98-100% and high anti-HBs geometric mean titres (GMTs) were observed in all study groups after three doses of hepatitis B vaccine. Significantly higher anti-HBs were seen in Group III, where six months is allowed between the second and the third hepatitis B vaccine doses, compared with Group I and II, where only 1-2 months separate the second and third doses. A fourth dose of vaccine was needed in both these groups to obtain anti-HBs levels as high as seen in Group III after three vaccine doses at 3, 4 and 10 months of age. The immune response to DT and OPV was similar in the study groups and the control group. It is concluded that a course of 10 micrograms doses of recombinant hepatitis B vaccine given simultaneously with DT and OPV elicits a strong anti-HBs response and does not interfere with the immune response to the other antigens.

Simultaneous administration of HB recombinant vaccine with diphtheria and tetanus toxoid and oral polio vaccine: a pilot study

An extensive vaccination program to be used in highly endemic areas is the main strategy against the spreading of hepatitis B. The purpose of this study was the evaluation of the immune response to the recombinant HB vaccine administered singly or at the same time as other compulsory vaccines anti-diphtheria, anti-tetanus and oral anti-polio. Evidence was found of the serological efficacy both of HB vaccine and compulsory vaccines with a percentage of seroconversion of 100%. However, the infants who received HB vaccine at birth and at the age of 1 month had titers of antiHBs higher than the infants who received HB vaccine at birth and at 3 months. No difference in antibody levels of compulsory vaccines was observed among the study groups and the controls who received only compulsory vaccines. Our results suggest that HB vaccination must be encouraged and pursued in all newborns.