Search PubMed⌕ Search

Biomedical subjects

A Safary

Publications and source records attributed to A Safary.

84 records · Page 5Linked to original sources
PubMed1983

Reactivity and immunogenicity of bivalent (AC) and tetravalent (ACW135Y) meningococcal vaccines containing O-acetyl-negative or O-acetyl-positive group C polysaccharide.

The immunogenicity and the reactivity of two bivalent (AC) and two tetravalent (ACW135Y) meningococcal vaccines containing either the O-acetyl-positive or the O-acetyl-negative group C polysaccharide were compared in healthy adolescent and adult volunteers. The vaccines contained high-molecular-weight, purified capsular meningococcal polysaccharides and were administered subcutaneously at a dose of 50 micrograms for each polysaccharide. Reactivity was low for all vaccines, and the tetravalent vaccines were not significantly more reactive than the bivalent vaccines. Immunogenicity was measured by assay of bactericidal antibodies in pre- and postvaccination sera. More than 90% of the vaccines had at least a fourfold increase in the bactericidal antibody titer against each group of meningococcus represented in the vaccines. Addition of polysaccharide W135 and polysaccharide Y to polysaccharides A and C did not alter the immunogenicity of the latter polysaccharides. Thus, there is no evidence of antigenic competition with the tetravalent vaccine. Comparison of the antibody response to the O-acetyl-positive and the O-acetyl-negative variants of group C polysaccharide in the bivalent vaccines, as measured by both bactericidal and enzyme-linked immunosorbent assays, indicates that in adults, the two types of group C polysaccharide are similarly immunogenic.

Adolescent↗
PubMedDate not supplied

Vaccination against hepatitis A in children aged 12 to 24 months [corrected].

BACKGROUND: Current hepatitis A vaccines are either licensed for children >2 years of age, as in the U.S. or Chile, or >1 year of age, as in Europe and other parts of the world. Recent recommendations for immunization against hepatitis A have included routine vaccination of children in areas or regions of higher endemicity. However, data on hepatitis A vaccination in toddlers aged between 1 and 2 years are scarce. METHODS: This open clinical study investigated the reactogenicity and immunogenicity of two doses (0, 6-month schedule) of an inactivated hepatitis A vaccine (Havrix pediatric, Glaxco SmithKline Biologicals, Rixensart, Belgium) in 120 seronegative children aged 12-24 months. RESULTS: Pain at the injection site and irritability were the most frequently reported local and general symptoms, respectively. No serious adverse events related to the study vaccine were reported. One month after the first dose, all but one subject had antibodies against hepatitis A with a GMT of 159 mIU/mL. After the booster dose, all had antibodies with a GMT of 2,939 mIU/mL. CONCLUSIONS: Our data show that the inactivated hepatitis A vaccine was well tolerated by these toddlers and that the vaccine elicits a good immune response.

Child, Preschool↗
PubMedDate not supplied

Inactivated hepatitis A vaccine: long-term antibody persistence.

During the clinical development of safe, well tolerated and immunogenic vaccines against hepatitis A the persistence of protective antibodies was estimated, based on relatively short observation periods of 18 months to 3 years. We report here on longterm persistence of antibodies in volunteers who participated in one of the early clinical trials on inactivated hepatitis A candidate vaccines. In a randomized trial three groups of altogether 110 healthy adults, initially hepatitis A virus (HAV) seronegative persons were vaccinated with an inactivated hepatitis A vaccine according to the schedule 0-1-2-12 months. One group received 180 ELISA units, one group 360, and one 720 ELISA units per dose. Blood samples were taken prior to the first vaccination and at months 1, 2, 3, 4, 6, 12, 13, 18, 24, 36 and 84. The decrease of antibodies was characterized by two disappearance rates: a rapidly decreasing component and a slower decreasing one becoming predominant ca 12 months after booster vaccination. The disappearance of antibodies could be described by a two-component model which holds for t > or = 13 months. The estimated disappearance rates for the slow component (annual decrease) was found to be 11 and 13% for the 180 and 360 El. U groups, respectively (the 720 El. U group showed no decline, which was probably due to the small sample size). The estimated persistence of antibodies within protective range varied between 24 and 47 years depending on individual titres reached at month 13 and vaccination dose.

Adult↗
PubMedDate not supplied

Follow-up immunogenicity of an inactivated hepatitis A virus vaccine in healthy children: results after 5 years.

Long-term persistence of hepatitis A virus (HAV) serum antibody in vaccinated children has not been demonstrated in previous studies. To study the long-term immunogenicity to HAV vaccine, three doses of strain HM 175 HAV vaccine with 360 enzyme-linked immunosorbent assay units were administered to 107 children, aged from 1.0 to 6.8 years, at 0, 1, and 6 months. The administration of one vaccine dose induced seropositivity (anti-HAV titer > or = 20 mIU ml-1) in 95% of all vaccinees at month 1. All subjects remained seropositive until month 6. The titers of HAV antibody remained above 20 mIU ml-1 in all subjects followed up to 60 months. The geometric mean titer (GMT) reached its peak (3802 mIU ml-1) at month 7, i.e. 1 month after the booster dose, and then declined until the end of follow-up at month 60 (661 mIU ml-1). A trend of higher GMT in female subjects persisted up to month 60. The changes of the GMT over time were best described by the regression equation: log (GMT) = 3.26-0.08 x (age in years) (r = -0.95, P = 0.014). According to this equation, the geometric mean concentration would reach 20 mIU ml-1 at around 24.5 years after the beginning of vaccination. In conclusion, those who completed the recommended three-dose inactivated HAV vaccination series remained seroprotective for at least 5 years. Theoretically, such a vaccination program can provide a protective period of over 20 years in children. This paper may be the first to describe at least 5-year immunogenicity of inactivated HAV vaccination in healthy children.

Child↗
PubMedDate not supplied

Safety and immunogenicity of hepatitis A vaccine in healthy adult volunteers.

The immunogenicity and adverse reaction of an inactivated hepatitis A (HA) vaccine were investigated. Sixty healthy adult volunteers who lacked antibody to HA virus (anti-HAV) received three doses of vaccine containing 720 enzyme-linked immunosorbent assay (ELISA) units (EL.U) according to a 0, 1 and 6 month schedule. Blood tests for serum liver enzymes and anti-HAV were performed at screening 7 days prior to, and 1, 6 and 7 months after the first dose. Anti-HAV was tested by radio immunoassay and ELISA for titre determination. The seroconversion rates measured by ELISA were 98.3% (59/60) at months 1 and 6 and 100% at month 7. Sixty-one per cent (109/180) of the documented injections were followed by local symptoms, essentially mild soreness at the site of injection; and 22.2% (40/180) by minor general symptoms including malaise, fatigue and lethargy. It is concluded that HA vaccine is highly immunogenic and safe. It may replace immunoglobulin as an effective method of preventing HA virus infection in adults.

Adult↗
PubMedDate not supplied

Immunogenicity and reactogenicity of two recombinant hepatitis B vaccines in healthy adolescents on two-dose schedule.

This is an open, randomized study to compare the immunogenicity and reactogenicity of two recombinant hepatitis B virus (HBV) vaccines. The HBV-NF is a new formulation with a new adjuvant phenoxyethanol which replaced the conventional adjuvant of a commercially available recombinant HBV vaccine (Engerix-B). These two vaccines had the same 20 micrograms hepatitis B surface antigen (HBsAg). They were administered to the deltoid muscle of 116 healthy adolescents, aged between twelve and eighteen years, according to the 0, 6-month schedule. Serum was taken at month 0, 1, 6, and 7. Antibody to HBsAg was tested by radioimmunoassay. Geometric mean titers of both vaccines displayed no significant difference at month 1, 6, and 7. Following the second dose of vaccine, the seroprotection titer (10 mIU/ml) rates at month 7 were 90.9% in HBV-NF and 93.4% in Engerix-B, respectively (p = 0.43). The incidences of local and general adverse reactions were from 3% to 7% without significant difference between the two vaccines and the reactions were all mild and tolerable. Based on this study, regimens of this two-dose schedule proved to be safe and immunogenic, which may provide a cost-effective alternative for HBV mass vaccination program in adolescents.

Adolescent↗
PubMedDate not supplied

[Clinical trial of Trive 1000 in long-term parenteral nutrition (author's transl)].

The authors report a study of long-term parenteral nutrition with a homogeneous media (produce? Solution?) containing glucido-lipidic calories and essential amino-acids. This solution has the advantage of an easy dosage of the number of calories and of grams of nitrogen to administer; it also decreases the risks of bacterial contamination from "handicraft" mixing and excessive manipulations.

Adult↗
PubMedDate not supplied

[The serological response to a recombinant DNA vaccine in the native residents of 2 hyperendemic hepatitis B areas in the Peruvian Amazonia].

UNLABELLED: In large areas of the Amazon jungle from Brazil, Colombia, Venezuela and Peru, it has been reported hyperendemic HBV and delta focus. In the Peruvian jungle we found up to 97% of prevalence of HBV, on the northern Jívaro tribes vs the southern tribes, Arawak, (65%). In this paper we studied 226 volunteers from 6 Jívaro and 3 Arawak villages, who accepted to be vaccinated with a DNA recombinant vaccine (ENGERIX B); all of them were previously HBsAg/Ab negatives but 55.5% of them were anti-core (IgG) positive. Our results show 84.9% of seroconversion to anti-HBs, and 73.5% was consider to be immunized (> 10 mIU/ml). Better response was observed in those that were HBcAb negative, coming from a low endemic area. We also observed a good vaccine response although we had to change months the response decreased up to 51.8% of seroimmunity. Higher anti-HBs titles was observed in the southern tribes: MGC of 416.3 mIU/ml. compared with the south: MGC: 182.2 mIU/ml. CONCLUSIONS: It is important to check previously, in hyperendemic areas, HBV markers, specially. It is important to receive the second dose between with the third dose up to 14 month. The immune response overall was good: the ABsAb titles obtained was in average, 290 mIU/ml (10.2-41,00). Apparently the vaccine do not suffer during the difficulties in transportation in the jungle. No side effects we shown during the vaccination program.

Adolescent↗
PubMedDate not supplied

Immunogenicity of an inactivated hepatitis A vaccine in healthy children: two years' follow-up.

To investigate the long-term immunogenicity of an inactivated hepatitis A vaccine in children, 100 healthy children, aged between 1 and 7 years old and all lacking the antibody to hepatitis A (HA) virus, were enrolled in this trial. They received 3 doses of strain HM 175 HA vaccine with 360 enzyme-linked immunosorbent assay (ELISA) units at 0, 1 and 6 months, respectively. Blood sampling for antibody and aminotransferases was performed 7 days before, then 1, 6, 7, 12, and 24 months after the first dose. The titers of antibody to HA virus were tested by radioimmunoassay and ELISA methods. All subjects became ELISA seropositive at Month 6 after two doses of vaccine. Except for one boy, 99 remained seropositive at Month 24, with a geometric mean titer of 1,148 mIU/ml. Antibody titers for females were significantly higher than those for males throughout the follow-up period. It was concluded that the inactivated HA vaccine used in the present trial was immunogenic and safe in children below seven years old. The vaccine-induced antibody persisted for at least two years in 99% of the vaccinees.

Child↗
PubMedDate not supplied

Comparison of the reactogenicity and immunogenicity of two different dose levels of hepatitis A vaccine in healthy children and adolescents.

An open study was performed to compare the reactogenicity and immunogenicity of an inactivated hepatitis A vaccine administered in two different doses and schedules to 460 healthy volunteers aged 3-18 years. Participants were randomized to two groups to receive either two doses of 720 ELISA Units (EL.U) inactivated hepatitis A per 0.5 ml dose according to a 0, 6-month schedule, or three doses of 360 EL.U according to a 0, 1, 6-month schedule. Transient local injection soreness was the most commonly reported symptom in almost half of both groups with no serious adverse events. One month after the primary course (one dose of 720 EL.U and two doses of 360 EL.U), 99% of 720 EL.U vaccinees had seroconverted, compared with 100% seroconversion in the 360 EL.U group. All vaccinees were seropositive after the booster dose of both vaccines with geometric mean anti-HAV titers of 2,359 and 2,967 mIU/ml in the 720 EL.U and 360 EL.U groups, respectively. The vaccine containing 720 EL.U of antigen per dose offers the advantage of convenience and acceptance of immunization afforded by a two-dose course of vaccination accompanied by a comparable antibody response with that achieved after three doses of vaccine containing 360 EL.U of antigen per dose.

Adolescent↗