Intradermal and intramuscular route for vaccination against hepatitis B. Comparison of higher-dose intradermal hepatitis B vaccination to standard intramuscular vaccination of healthcare workers. Immunogenicity of low-dose intramuscular and intradermal vaccination with recombinant hepatitis B vaccine. Comparison of two immunization schedules with recombinant hepatitis B vaccine and natural immunity acquired by hepatitis B infection in dialysis patients. A follow-up study of combined vaccination with plasma-derived and recombinant hepatitis B vaccines in infants. Clinical evaluation of low dose intradermally administered hepatitis B vaccine: a comparison of plasma-derived and recombinant yeast-derived vaccines. Intradermal hepatitis B vaccination in a large hospital employee population. Low-dose (2 micrograms) hepatitis B vaccination in medical students: comparable immunogenicity for intramuscular and intradermal routes. Simultaneous vaccination against hepatitis A and B: results of a controlled study.
A recombinant hepatitis B vaccine was administered to high-risk hospital personnel by intramuscular (20 micrograms) or intradermal (2 micrograms) injections for the primary immunization (n = 69) with three doses and booster immunization (n = 51) with one dose. Basic vaccination performed intramuscularly gave rise to significantly higher seroconversion levels (97.2% versus 78.1%) and geometric mean titres of antibody (1649 versus 126 IUl-1) as compared with the intradermal route. Intradermal administration did not boost antibody titres in patients previously vaccinated intradermally. Adverse reactions were not serious or severe. The intramuscular route is recommended as the procedure of choice when vaccinating against hepatitis B. To compare the immunogenicity of hepatitis B vaccine administered via intradermal (ID) versus intramuscular (IM) route.
                Subjects chose either to specify the route of immunization or to undergo random allocation to vaccination by the ID (0.15 mL) or the IM (1.0 mL) route. Yeast-derived recombinant hepatitis B vaccine was given at 0, 30, and 180 days. Hepatitis B surface antibody (HBsAb) and hepatitis B core antibody (HBcAb) were measured by microparticle enzyme immunoassay.
                763 subjects were enrolled. Baseline screening identified 65 subjects (8%) who were positive for HBsAb or HBcAb. Vaccination was completed by 590 (85%) of 698 enrollees (370 ID, 220 IM). Seroconversion rates (geometric mean titers [GMT]>0 IU/mL HBsAb) for those vaccinated ID were 99% and 96% for screening at 9 months and 1 year post-vaccination, respectively; subjects vaccinated intramuscularly had similar rates of 95% and 96%. Seropositivity rates (GMT > or = 10 IU/mL HBsAb) showed a similar pattern, with 95%, 92%, and 73% at 9 months and 1 and 2 years, respectively, for those vaccinated ID, and 94%, 93%, and 81% for those having IM vaccination. GMT for HBsAb was significantly higher for individuals vaccinated IM than for those vaccinated ID (P<.0001). The GMT ratio for the IM and ID routes decreased over time, being 9.3 at 9 months, 7.8 at 1 year, and 5.9 at 2 years. An unanticipated side effect of intradermal vaccination was skin discoloration at injection sites, which persisted for at least 2 years postvaccination. Two thirds (112/166) of respondents reported that they would have selected the ID route despite the discoloration.
                Higher-dose ID vaccination (3 vs 1 microg per injection) uses one sixth of the dose required for standard IM vaccination. It is a cost-effective way to vaccinate populations against hepatitis B virus, but the long-term efficacy of the ID route must still be investigated. The study is a randomized trial using recombinant DNA vaccine to determine whether an intramuscular 10 micrograms dose or intradermal 2 micrograms induces satisfactory anti-HBs levels compared to the standard dose of intramuscular 20 micrograms. Participants were 359 healthy medical and nurse students randomly allocated to one of the three groups: Group I-IM 20 micrograms; Group II-IM 10 micrograms; Group III-ID 2 micrograms at 0, 1 and 6 months. Anti-HBs titres were measured after complete vaccine schedule by ELISA/Pasteur. Baseline variables were similar among groups and side effects were mild after any dose. Vaccines in the IM-10 micrograms group had seroconversion rate and geometric mean titre (GMT 2344 IU L-1), not significant different from the IM-20 micrograms group (GMT 4570 IU L-1). On the contrary, 21.4% of the ID-2 micrograms recipients mount antibody concentration below 10 IU L-1 and GMT of 91 IU L-1, a statistically significant difference compared with the standard schedule IM-20 micrograms (p < 0.001). A three dose regimen of half dose IM could be considered an appropriate schedule to prevent hepatitis B in young health adults which is of relevance to the expansion of hepatitis B vaccine programme. In a prospective study over a 2-year period we compared two practical dosage schedules to vaccinate dialysis patients against hepatitis B virus (HBV) infection using a yeast-derived recombinant hepatitis B vaccine (Engerix-B). In addition, the natural history of this acquired immunity was compared with that developed through HBV infection in dialysis patients and healthy subjects. Patients on dialysis treatment (haemo or peritoneal) who were tested to be negative for hepatitis B surface antigen (HBsAg), anti-HBs and anti-HB core were allocated at random to receive HB vaccine according to one of the two schedules. The two groups receiving the vaccine were matched for age, sex, mean duration on dialysis and the form of dialysis treatment received. The group of patients who received a four-dose schedule (at 0, 1, 2 and 6 months) of 40 micrograms of HB vaccine each time (group 2) achieved a seroconversion rate of 79% 1 month after the last dose (at month 7) compared with a seroconversion rate of 55% in those who received three doses (at 0, 1 and 6 months) of 40 micrograms each (group 1). Healthy controls who received half the amount of vaccine on a three-dose schedule (group 3) attained 100% seroconversion (p < 0.05). When retested at 24 months, 30% of seroconverters in group 1 had lost their protective immunity, compared with only 6% in group 2 and 15% in group 3. The magnitude of antibody response (total and anti-(a)-specific) was assessed in the vaccinees at 24 months and compared with that of two other control groups, dialysis patients (group 4) and healthy volunteers (group 5), who had acquired immunity from HBV infection. In general, the total and anti-(a)-specific HBs titres in the dialysis patients (groups 1, 2 and 4) were lower than in their corresponding healthy controls (groups 3 and 5), irrespective of whether the protective immunity was acquired by vaccination or HBV infection. However, the anti-HBs titres in dialysis patients who received four doses were significantly higher than in those who received only three doses (p < 0.05), which indicated a better protective immunity in favour of the former regime. The magnitude of antibody response in the vaccinees of groups 2 and 3 compared well with their respective controls, groups 4 and 5, who had acquired their immunity through HBV infection. This implied that the yeast-derived vaccine was sufficiently immunogenic and provided lasting protection in patients and healthy subjects vaccinated by an appropriate dosage schedule.(ABSTRACT TRUNCATED AT 400 WORDS) This study was aimed to evaluate the efficacy and immunogenicity of combined hepatitis B vaccination with plasma-derived vaccine (PDV) and recombinant vaccine (RV). A total of 329 infants was recruited, including 224 high-risk infants born to hepatitis B e antigen-positive mothers and 105 low-risk infants born to hepatitis B e antigen-negative mothers. The high-risk infants received four doses of hepatitis B vaccine at 0, 1, 2 and 12 months of age with five different schedules. Group A1 and A2 infants were vaccinated with PDV as the first dose and RV (SB vaccine for group A1, MSD vaccine for group A2) as the remaining three doses. Group B1 and group B2 infants were vaccinated with PDV as the first two doses and RV (SB vaccine for group B1, MSD vaccine for group B2) as the remaining two doses. Group C infants received four doses of PDV. Low-risk infants were vaccinated with PDV at birth, and RV at 1 and 6 months of age (group D1, using SB vaccine; group D2, using MSD vaccine). At completion of vaccination schedules, 20 of 224 high-risk infants (9%) were positive for hepatitis B surface antigen. The overall protective efficacy was 90%. Hepatitis B surface antibody (anti-HBs)-positive rate ranged between 94 and 100% among the remaining infants. The protective efficacy and immunogenicity were similar among groups except that the mean level of anti-HBs in group C, D1 and D2 infants tended to be lower than that of the other four groups. To ensure an optimal immune response, four doses of vaccine are recommended in high-risk infants when two types of vaccine are to be used in combination. A study of the safety and immunogenicity of plasma-derived and yeast-derived recombinant hepatitis B vaccines administered by the intradermal route is reported. Three groups of medical students were inoculated intradermally at 0, 1 and 6 months with 2 micrograms of vaccine. Group 1 (n = 24) were administered plasma-derived vaccine (Green Cross HB-vaccine), group 2 (n = 21) yeast-derived recombinant vaccine (Engerix B), and group 3 (n = 13) two doses of plasma-derived vaccine with a third dose of yeast-derived vaccine. One month after administration of the third dose of vaccine, seroconversion rates in each of the three groups were 83, 100 and 92%, respectively, with anti-HBs geometric mean titres (GMT) of 329 IU l-1, 1390 IU l-1 and 1061 IU l-1. Although differences in seroconversion rates were not statistically significant, the GMT in group 1 was significantly lower than that in group 2 (p less than 0.01) and group 3 (p less than 0.05). The results presented show that intradermal administration of plasma-derived or yeast-derived vaccine, or a combination of the two, can provoke an effective immunogenic response to hepatitis B virus at approximately 10% of the cost of intramuscular vaccination. In this study administration of yeast-derived vaccine yielded better results than plasma-derived vaccine when administered by the intradermal route. The intradermal route of hepatitis B vaccine administration has been tested in several clinical trials and has produced various degrees of immunogenicity, but usually among small groups of participants. To assess more adequately the immunogenicity of hepatitis B vaccine using the intradermal route, the Centers for Disease Control conducted a clinical trial among 425 well health-care workers in a hospital setting. Participants were randomly assigned to one of two treatment groups: those receiving a 20 micrograms intramuscular injection, and those receiving a 2 micrograms intradermal injection. Participants received the plasma-derived hepatitis B vaccine by the standard schedule at 0, 1 and 6 months, and serum samples were collected at 3, 8, 12 and 24 months after the first dose. Antibody response rates (anti-HBs titre greater than or equal to 10 sample ratio units by radioimmunoassay) for the intradermal vaccination group were consistently lower than those for the intramuscular vaccination group at each testing interval. The differences were greatest for the 3-month test and decreased over time. Geometric mean titres for anti-HBs for the intradermal group were significantly lower than those for the intramuscular group at the 8-month test point. In addition to inoculation route, factors of gender, smoking and age were found to have significant effects on immune response. The results suggest that intradermal vaccination with hepatitis B vaccine may be appropriate under certain conditions and for certain population subgroups. In a randomized controlled trial, 165 healthy medical students were immunized either by the intramuscular route (IM group) or by the intradermal route (ID group) with low-dose (2 micrograms) plasma hepatitis B vaccine (HB-VAX) at months 0, 1, 2, and 6. At month 7, protective immunity (anti-HBs greater than 10 IU/l) was observed in 90% (95% confidence interval [Cl]: 84-97) of group IM and in 94% (95% Cl: 89-99) of group ID; also geometric mean titres (IM: 533 IU/l; ID:541 IU/l) were very similar at month 7. Sixty-six (IM: 29; ID: 37) of 107 vaccinees with anti-HBs less than 1,000 IU/l at month 7 received a 2 micrograms booster injection at month 12. Long-term immunity (anti-HBs greater than 1,000 IU/l) was finally observed in 58% for group IM and 66% for group ID. For low-dose hepatitis B immunization, which reduces costs to about 16%, the IM route is to be preferred in young healthy individuals in view of an ease of administration, avoidance of long-term local side effects, and the known protective immunity of intramuscularly induced anti-HBs antibodies. Hepatitis A and hepatitis B are endemic in many countries and must be considered as serious health risks for large parts of the world population. Simultaneous or combined vaccination against these two diseases would therefore be most advantageous. In order to investigate possible interactions between these vaccines with respect to their tolerability and immunogenicity, we conducted a randomized prospective study comparing single and simultaneous administration of the two vaccines. Three groups of healthy volunteers, each with 55 persons, were included in the study. All were negative for hepatitis A and hepatitis B markers and had normal serum liver enzyme values. Group I received hepatitis A vaccine (720 ELISA units) into the left deltoid muscle, group II received hepatitis B vaccine (20 micrograms) into the right deltoid muscle and group III received hepatitis A vaccine into the left, and hepatitis B vaccine into the right deltoid muscle. Three doses of the vaccines were administered at 0, 1 and 6 months. Local and systemic reactions were monitored by means of questionnaires. Blood samples for determination of antibody to hepatitis A virus (anti-HAV) and antibody to hepatitis B surface antigen (anti-HBs) and of serum SGOT and SGPT levels were drawn at months 0, 1, 2, 6 and 7. There were no serious general and only mild local reactions. The mean serum SGOT and SGPT values remained in the normal range in all groups. The seroconversion rates and mean geometric titres of the anti-HAV and anti-HBs antibodies were similar when the vaccines were administered separately or simultaneously. There were no significant differences between the compared groups.(ABSTRACT TRUNCATED AT 250 WORDS)
PDV significantly prevents hepatitis B events. RV seems to be able to elicit similar protective anti-HBs levels. The intramuscular route with 20 µg RV was significantly more effective compared with the intradermal route with 2 µg RV as was the standard schedule compared with a rapid schedule and deltoid intramuscular injection compared with the gluteal intramuscular injection. It is unclear if booster vaccination of non-responders offers higher anti-HBs seroconversion and hepatitis B vaccine prevents the infection of hepatitis B mutants in health-care workers.