Safety and immunogenicity of a recombinant Borrelia burgdorferi outer surface protein A vaccine against lyme disease in healthy children and adolescents: a randomized controlled trial.

OBJECTIVE: A recombinant lipoprotein outer surface protein A (OspA) Lyme disease (LD) vaccine (LYMErix) has been shown to be safe and effective in preventing LD in adults and in adolescents 15 years of age and older. Children are at risk for developing LD. This clinical study was conducted to address the safety and immunogenicity of LD vaccine in children 4 to 18 years of age. METHODS: A randomized, placebo-controlled clinical trial was conducted at 17 investigational sites in Lyme-endemic areas in the United States. Immunogenicity data from this study also were compared with data obtained from the adult efficacy study. A total of 4090 healthy children and adolescents (age range: 4-18; mean age: 10.4 years) were randomized; 4087 were vaccinated, and a subset of 301 children participated in the immunogenicity analysis. Children were randomized to receive either 30 microgram of LD vaccine (N = 3063) or placebo (N = 1024) on a 0, 1, 12-month schedule. Safety assessments evaluated both solicited (local: redness, swelling, and pain; general: fever, headache, fatigue, arthralgia, and rash) and unsolicited adverse events. Serum specimens were collected at month 0 or month 2, and months 6, 12, and 13. RESULTS: Solicited reactogenicity data revealed a higher incidence of local injection site reactions and general symptoms (fever, headache, fatigue, and arthralgia) in vaccine than placebo recipients. The majority of events were limited in duration (mean: 2-3 days) and were mild to moderate in severity. The total IgG anti-OspA geometric mean titer (GMT) in the pediatric vaccine recipients at month 13 was as good as and statistically higher than the GMT in the adult cohort at month 13 (27 485 enzyme-linked immunosorbent assay units [EL.U]/mL vs 8216 EL.U /mL). All of the pediatric vaccine recipients attained a level of antibody concentration >/=1400 EL.U/mL (proposed seroprotective level) compared with 90% of adults attaining levels >/=1400 EL.U/mL in the efficacy trial. CONCLUSIONS: LD vaccine administered on a 0, 1, 12-month schedule generally is well tolerated and immunogenic in children 4 to 18 years of age. The safety profile consists of mild to moderate local injection site reactions and flu-like symptoms of limited duration and did not worsen with subsequent injections. IgG GMT at month 13 was threefold higher than the month 13 GMT obtained in the adult efficacy study. This higher immune response in children should provide protection against LD.

Reactogenicity and immunogenicity of a Lyme disease vaccine in children 2-5 years old.

Two doses of a recombinant Lyme disease vaccine (15 and 30 microg) were administered to children 2-5 years old (0-1-month schedule) and were well tolerated. Both doses were highly immunogenic with geometric mean titers 1 month after vaccination of 4366 and 9877 ELISA units (EU)/mL, respectively. Nearly all subjects had antibody levels of > or = 1400 EU/mL, suggesting protective tick titre for one tick season.

Safety and immunogenicity profile of a recombinant outer-surface protein A Lyme disease vaccine: clinical trial of a 3-dose schedule at 0, 1, and 2 months.

OBJECTIVES: This study compared the tolerability of a Lyme disease vaccine administered intramuscularly at 0 and 1 months with that of a vaccine administered at 0, 1, and 2 months to determine (1) whether adding a third dose of vaccine 1 month after the second would affect the safety profile, and (2) whether a shortened vaccination schedule of 0, 1, and 2 months would provide an immune response similar to that obtained with vaccine administered at 0, 1, and 12 months. BACKGROUND: An efficacy trial of a Lyme disease vaccine had demonstrated safety and efficacy against definite (clinically manifested and laboratory-confirmed) Lyme disease after 3 doses at 0, 1, and 12 months and resulted in 90% of subjects having titers > or =1400 enzyme-linked immunosorbent assay units (EL.U)/mL (the proposed seroprotective level for 1 tick season). METHODS: This multicenter, open-label, prospective, randomized study assessed the safety and efficacy of different doses of a recombinant outer-surface protein A (OspA) vaccine in 956 volunteers aged 17 to 72 years from 3 Lyme disease-endemic sites. Blood samples were collected at months 0, 2, 3, 12, and 13 to assess total immunoglobulin-G anti-OspA titers. RESULTS: Most adverse events were transient and mild to moderate. The geometric mean antibody titer increased 2.8-fold from month 2 (1786 EL.U/mL to 4842 EL.U/mL), and approximately 90% of the volunteers had a titer > or =1400 and 99% had a titer > or =400 EL.U/mL (the mini- mum seroprotective level at any given time) after the third dose. An antibody kinetics model predicts that protection would last for a typical tick-transmission season. CONCLUSIONS: In volunteers aged 17 to 72 years, 3 doses of vaccine administered in 2 months was well tolerated, more immunogenic than 2 doses, and provided a higher probability of protection before exposure or travel to Lyme disease-endemic areas.

A phase I trial in HIV negative healthy volunteers evaluating the effect of potent adjuvants on immunogenicity of a recombinant gp120W61D derived from dual tropic R5X4 HIV-1ACH320.

Thirty healthy HIV negative volunteers were randomised to receive 200 micrograms of rgp120W61D in either: 3D-MPL and QS21, with an oil and water emulsion (SBAS-2) (13); or 3D-MPL and QS21 (SBAS-1) (11); or alum (six). Immunizations were given at 0, 4 and 28 weeks and 23 (77%) participants completed the schedule. Adverse events were more frequent (P < 0.001) and more severe (P < 0.001) in the SBAS-2 group. Binding antibodies to the homologous rgp120W61D were detected after the first immunisation only in those receiving SBAS-1 and SBAS-2, were maximal after the third immunization in all three groups, and persisted to week 84 only in the novel adjuvant groups. These differences were significant (p = 0.02). Neutralising antibodies to TCLA-strains of HIV-1 were observed after the second immunization in all three groups, were maximal after the third immunization, but did not neutralise homologous or heterologous PBMC derived primary HIV-1 isolates. Proliferative T-cell responses to rgp120W61D were maximal after the second immunization and reached very high values in the SBAS-2 group. HIV-1 specific CD8+ MHC Class I restricted cytotoxic T-lymphocytes were not seen in a subset of participants tested at a single timepoint. SBAS-2 with rgp120W61D induced antibody titres as high as those seen in HIV infection, but the quality of the antibodies remained different in that there was no evidence of primary isolate neutralisation. Although cell-mediated immunity was enhanced by SBAS-2 in terms of lymphoproliferative responses, HIV-1 specific CD8+ cytotoxicity was not demonstrated.

A single dose, combined vaccine against typhoid fever and hepatitis A: consistency, immunogenicity and reactogenicity.

BACKGROUND: Vaccines against hepatitis A and typhoid fever are well established and have an excellent safety and immunogenicity profile. Yet these diseases, which share the same geographic distribution, remain an important cause of morbidity in travelers to endemic countries. Combined vaccination provides dual protection and improves compliance and coverage for travelers. METHODS: This multicenter study evaluated the consistency of three lots of combined hepatitis A and typhoid fever vaccine. A total of 462 healthy subjects, aged 15-50 years, were enrolled and randomly allocated to 3 groups. The single dose of vaccine contains 25 microg typhoid Vi polysaccharide and at least 1,440 ELISA units of inactivated hepatitis A in a 1 mL dose. RESULTS: Bioequivalence of all production lots was shown in terms of safety and immunogenicity. Pain at injection site was the most frequent reported local symptom, and headache was the most frequent reported general symptom. As early as 14 days after immunization >95% of the subjects were positive for anti-Vi antibodies and >86% were positive for anti-HAV antibodies. The GMTs and seropositivity rates were maintained during the 6 month follow-up. CONCLUSION: The first combined vaccine against typhoid fever and hepatitis A was safe and elicited a very good immune response, with the majority of subjects seropositive at 1 month for both antigens. This combined vaccine offered more convenience and rapid seroconversion to travelers.

Immunogenicity of a recombinant Borrelia burgdorferi outer surface protein A vaccine against Lyme disease in children.

BACKGROUND AND OBJECTIVE: A recombinant lipoprotein vaccine against Lyme disease, containing 30 microg of Borrelia burgdorferi outer surface protein A (OspA) with aluminum adjuvant, has been shown in a large US field trial of subjects >/=15 years of age to offer 76% efficacy against clinical Lyme disease after 3 injections given at 0, 1, and 12 months. Lyme disease is also an important problem in children; thus, OspA vaccine trials in children are needed. The purpose of this study was to investigate the safety and immunogenicity of 2 different doses of lipoprotein OspA with aluminum adjuvant vaccine in healthy children 5 to 15 years of age in a double-blind, randomized study. STUDY DESIGN: In a double-blind study, 250 children from the Czech Republic were randomly assigned to receive 15 microg or 30 microg of OspA vaccine at 0, 1, and 2 months. Serum samples, obtained before vaccination and 1 month after the second and third doses, were analyzed for antiOspA antibody. Solicited and unsolicited symptoms were collected from diary cards. RESULTS: Local pain at the injection site was reported by approximately 76% of the 250 children. Headaches (after 5% to 18% of the injections) and malaise (after 2% to 16% of the injections) were the most frequently reported general symptoms. Local and generalized symptoms were not different between the 15 microg and 30 microg groups, and all symptoms resolved within 4 days. Both doses were highly immunogenic, with the 30 microg dose eliciting higher antibody levels. Seroconversion occurred in 99% of the 250 children. CONCLUSIONS: The OspA vaccine against Lyme disease was well tolerated and highly immunogenic in children.

Potent induction of focused Th1-type cellular and humoral immune responses by RTS,S/SBAS2, a recombinant Plasmodium falciparum malaria vaccine.

The RTS,S/SBAS2 vaccine confers sterile protection against Plasmodium falciparum sporozoite challenge. The mechanisms underlying this are of great interest, yet little is known about the immune effector mechanisms induced by this vaccine. The immune responses induced by RTS,S/SBAS2 were characterized in 10 malaria-naive volunteers. Several epitopes in the circumsporozoite protein (CSP) were identified as targets of cultured interferon (IFN)-gamma-secreting CD4+ T cells. RTS,S-specific IFN-gamma-secreting effector T cells were induced in 8 subjects; this ex vivo response mapped to a single peptide in Th2R. CSP-specific CD8+ cytotoxic T lymphocytes were not detected. RTS, S-specific IFN-gamma production was universal, whereas interleukin-4 and -5 production was rare. RTS,S-specific lymphoproliferative responses and antibodies to CSP were strongly induced in all volunteers. Responses waned with time but were boostable. Thus, RTS, S/SBAS2 is a potent inducer of Th1-type cellular and humoral immunity. These results highlight possible immune mechanisms of protection and have important implications for vaccine design in general.

Alternative vaccination schedules (0, 1, and 6 months versus 0, 1, and 12 months) for a recombinant OspA Lyme disease vaccine.

We have compared the immunogenicity profile of a recombinant lipoprotein outer-surface protein A (OspA) Lyme disease vaccine administered on schedules of 0, 1, and 6 months (group 1) or 0, 1, and 12 months (group 2) to 800 healthy subjects, aged 15-50 years. One month after the second dosing, geometric mean titers of IgG antibodies to OspA were 1,309 ELISA units (EL.U)/mL in group 1 and 1,404 EL.U/mL in group 2. One month after the third dosing, the titers were 7,205 EL.U/mL and 10,659 EL.U/mL, respectively. Using bioequivalence methodology, we showed that the two vaccination schedules elicit an equivalent immune response 1 month after administration of dose 3: at that point, 91%-93% of all subjects had titers > or =1,400 EL.U/mL, proposed to be protective for one tick season. The vast majority of local and systemic symptoms were mild to moderate and of limited duration. The 0, 1, and 6 months vaccination schedule is a viable alternative to the 0, 1, and 12 months schedule and can provide protection against Lyme disease during one tick season.

Concomitant vaccination against hepatitis A and typhoid fever.

BACKGROUND: The purpose of this study was to evaluate the reactogenicity and immunogenicity of a hepatitis A vaccine (Havrix-1440TM) when administered simultaneously with a Vi polysaccharide typhoid vaccine. METHODS: Two open, randomized studies were conducted using 2 and 4 treatment groups respectively, at the Clinique Notre-Dame de Grâce, Belgium (Study 1) and University Hospital of Hradec Kralové, Czech Republic (Study 2). SUBJECTS: Healthy adults aged 18-50 years were administered either both vaccines concomitantly in separate arms or a single injection of the two vaccines mixed extemporaneously (Study 1), or one injection of each vaccine alone, or the combined vaccine, or both vaccines concomitantly in separate arms (Study 2). The study measured solicited and unsolicited signs and symptoms until 28 days post-vaccination. Anti-hepatitis A and anti-Vi titers were determined in pre- and post-vaccination sera. RESULTS: The vast majority of local and general symptoms were mild to moderate and all resolved without sequelae. No serious adverse events were reported in either study. In study 1, geometric mean antibody titers (GMTs) were similar after extemporaneous syringe mixing of both vaccines (anti-Vi = 1159 EL.U/mL; anti-HAV = 302 EL.U/mL) and after concomitant vaccination (anti-Vi = 1331 EL.U/mL; anti-HAV = 367 EL. U/mL). In study 2, GMTs following vaccination with either vaccine alone, both vaccines administered concomitantly or as a combined vaccine (anti-Vi: 1307, 1247 and 942 EL.U/mL, respectively; anti-HAV: 462, 517 and 432 EL.U/mL, respectively) were not significantly different (p = .45 for anti-HAV, p = .18 for anti-Vi). Seroconversion rates were > 94.4% in all cases. CONCLUSIONS: The inactivated hepatitis A and Vi polysaccharide typhoid vaccines are safe and well tolerated when administered simultaneously (mixed or concomitant) and as a combined vaccine. Subjects seroconverted to both antigens to the same extent as the monovalent vaccines and there was no cross-interference in the immune profiles of the vaccines.

Clinical and immunological assessment of a candidate Lyme disease vaccine in healthy adults: antibody persistence and effect of a booster dose at month 12.

A candidate Lyme vaccine was administered to 20 adult volunteers following a 0, 1, 2 months vaccination schedule, with a booster at 12 months. An immune response, assessed as 'LA-2 equivalent' antibody titres using an inhibition ELISA, was induced in all vaccinees which persisted until the booster. Titres were increased 25-fold following the booster and persisted through month 24. There was a good correlation between 'LA-2 equivalent' antibody titres and a bactericidal assay (r2 = 0.86). Local symptoms were mild, resolving spontaneously within 72 h, with no reports of rash, arthralgia or other systemic symptoms. This Lyme vaccine was safe, well-tolerated and elicited an antibody response in all volunteers which persisted at least 12 months after the booster.

Longterm survey (7 years) in a population at risk for Lyme borreliosis: what happens to the seropositive individuals?

In 1986, a 26% seroprevalence of IgG- anti-Borrelia burgdorferi antibodies was observed among 950 orienteers and the incidence of new clinical infections was 0.8%. In 1993, a total of 305 seropositive orienteers were reexamined. During that time, 15 cases (4.9%) of definite/probable Lyme disease occurred in this seropositive group (12 skin manifestations and 3 monoarticular joint manifestations). Among the 12 definite cases, 9 showed new clinical infections (7 EM, 1 acrodermatitis chronica atrophicans, 1 arthritis), and 3 were recurrent (2 EM, 1 arthritis). The annual incidence (0.8%) in this seropositive group was identical to the incidence observed among the whole population in 1986. The individual antibody titer decreased slightly but the seroreversion rate was low (7%). Serology was not very helpful in identifying clinical cases and evolutions, and it can be stated, that a positive serology is much more frequent in this risk group than clinical disease.

Evaluation of the safety, reactogenicity and immunogenicity of three recombinant outer surface protein (OspA) lyme vaccines in healthy adults.

The safety, reactogenicity and immunogenicity of three candidate Lyme vaccines based on recombinant outer surface protein (OspA) presented in either lipidated or unlipidated forms, were assessed in 300 seronegative volunteers. Subjects received three doses of one of the three formulations at monthly intervals and were evaluated for antibody levels and the presence of symptoms after each dose. All formulations proved to be safe, the majority of local reactions being reported as mild, and all general symptoms were perceived to be either-mild or moderate in intensity. No subject refused a subsequent vaccine dose. All subjects were tested for both anti-OspA IgG and LA-2 equivalent antibodies up until day 84. All three vaccines induced an immune response but subjects who received lipoprotein OspA had the highest anti-OspA IgG and LA-2 equivalent GMTs after each dose and this was also true for the subset of subjects tested on day 180. The lipoprotein OspA group also had the largest number of subjects who remained seropositive for anti-OspA IgG antibodies. As the lipoprotein formulation produced the strongest immune response, with symptoms which were acceptable to all the vaccinees, we suggest further development of this vaccine.

Kinetics of humoral antibody response to trivalent inactivated split influenza vaccine in subjects previously vaccinated or vaccinated for the first time.

We studied differences in immune responses after first time immunization with a trivalent inactivated split influenza vaccine, or after vaccination in the preceding year, in 42 healthy volunteers (40 +/- 13 years). Sequential serum samples were collected over 40 weeks. Previously vaccinated volunteers exhibited 40-92% protective antibody levels in their prevaccination sera. Subjects vaccinated for the first time had higher response rates and meanfold antibody increases than those vaccinated previously. Both groups had protective antibody titres 59% 7 days after vaccination and 70% of vaccinees maintained protective antibody titres after 280 days. The results corroborate earlier findings on the rapid immune response and may have a bearing on future vaccination policy.

Immunogenicity of an inactivated split influenza vaccine in institutionalized elderly patients.

The immunogenicity of influenza vaccination in elderly institutionalized patients, with a variety of clinical disorders, was tested in an open multicenter study involving 495 people (mean age 80 years). Vaccination with an inactivated split influenza vaccine (Fluarix) was clinically well tolerated. For all age ranges and all strains of virus, the vaccine elicited a humoral response which surpassed the European Community requirements for influenza vaccines in adults over 60 years. The geometric mean titers for all vaccine strains were significantly increased 28 days after vaccination, and remained higher than prevaccination levels after 6 months. These immunological parameters were unaffected by the clinical status of the patients.