PubMed Health⌕ Search

Biomedical subjects

N Ajjan

Publications and source records attributed to N Ajjan.

At least 19 recordsLinked to original sources
PubMed2002

[Efficacy and tolerance of vaccinations in premature infants].

Immunization may prevent an enhanced risk of infectious diseases, providing that it is completed on time. A review of the literature summarizes several studies on effectiveness, safety and duration of protection in preterm infants. Immune maturation depends on chronological age rather than gestational age. Then immunization against diphteria-tetanus-pertussis-poliomyelitis-Haemophilus influenzae b should be initiated at 2 months of age and completed prior than 6 months. The youngest preterm infants, still hospitalized at 8 weeks of age should be monitored following the first immunization as they may develop apnea episodes, probably linked with the pertussis component of the vaccine. In premature, BCG vaccination induces a delayed hypersensitivity to tuberculin less important than in full-term neonates, and should not be given right after birth in newborns less than 33 weeks of gestational age. Hepatitis B vaccination should be offered as soon as two months of age and even at birth to children born from HBs Ag carriers. Neither duration of immunity, nor safety are modified by prematurity.

Age Factors↗
PubMed1993

[Pre-exposure rabies immunization in occupational exposed milieu. A 5-year prospective and comparative study of immunogenicity].

Pre-exposure rabies immunization has been the object of numerous immunogenicity studies with cultivated cell vaccines. Several primary immunizations and booster injection schedules have been suggested. The purpose of the present study was to compare simultaneously the immunogenicities of two vaccines at 5 years and those of two primary immunization schedules with a booster injection at 1 year. We compared the vaccine prepared from Vero cell cultures (PVRV) versus the reference vaccine prepared from human diploid cell culture (HDCV). We also compared primary immunization with 2 injections (on days 0 and 28) versus 3 injections (on days 0, 7 and 28). This phase IV study was prospective, randomized and conducted on open cohorts, according to a factorial plan defining four modalities (HDCV 2, HDCV 3, PVRV 2, PVRV 3). The study involved 312 volunteers of both sexes, aged from 15 to 65 years and exposed to rabies by their profession. The vaccines were injected intramuscularly in the deltoid region. Immunogenicity was evaluated by staged titering of neutralizing antibodies, using immunofluorescence. Seroprotection levels and mean geometrical means of titers were compared. The 3 injections schedule proved to be significantly superior to the 2 injections schedule. No difference could be clearly elicited between the two vaccines. The worst results were obtained with PVRV 2, with a 68.3 percent seroprotection rate at five years; with the other modalities this rate was 93.1 percent or more. We therefore recommend the following procedure: primary immunization by 3 injections, with a booster dose at 1 year, particularly when PVRV is used. It seems that the seroprotection obtained in this manner would make it possible to envisage a booster injection every 5 years.

Adolescent↗
PubMed1992

[Brucella vaccination in professionally exposed subjects. Prospective study].

This prospective phase IV study on cohort concerns a vaccine made of the phenol-insoluble fraction of Brucella abortus biotype 1 (B19 strain). Three hundred and three professionally exposed subjects entered the study; 161 out of 182 subjects (88.5 percent) with negative response to an intradermal test for detection of previous contamination accepted to be vaccinated. Booster injections were given 18 and 36 months after vaccination. Local pain was observed after 45.2 percent of injections and moderate systemic reactions after 5 percent of injections. Seropositivity after primary vaccination reached 80 percent. The booster injection, justified by a major decrease of this rate after 18 months, gave exactly the same response of the thymo-independent type. This vaccinal schedule did not result in detectable hypersensitivity. The clinical effectiveness of the vaccine could not be evaluated accurately because of the insufficient number of subjects. The possibility of subclinical infection in vaccinated subjects calls for wider comparative studies of vaccinated versus non-vaccinated subjects.

Brucella Vaccine↗
PubMed1989

Comparative study of the safety and protective value, in pre-exposure use, of rabies vaccine cultivated on human diploid cells (HDCV) and of the new vaccine grown on Vero cells.

The object of the study is to compare the tolerance and the efficacy of a new inactivated rabies vaccine grown on Vero cells (PVRV), with the vaccine cultivated on human diploid cells (HDCV), using the schedule recommended by WHO for pre-exposure on days 0, 7 and 21. Of students exposed to a risk of rabies at Alfort Veterinary School, 144 volunteers received either HDCV or PVRV vaccine. No student received a booster between the first blood sample before immunization on day 0 and the last antibody titration 21 months after the beginning of immunization. No serious side-effect occurred with either vaccine, although some vaccinees complained of redness, induration or local pain and, exceptionally, of fever. The study indicates the excellent immunogenicity of both HDCV and PVRV vaccines in all vaccinees. The geometric mean of antibody titres shows a higher titre in the PVRV group and a rapid decline in immune response with both vaccines, four months after the first injection, followed by a stabilization of the antibody level throughout the rest of the study. It should be noted, however, that very few individuals were found to be seronegative 21 months after the first injection.

Adult↗
PubMed1988

[20 years' use of the diphtheria-pertussis-tetanus vaccine].

Between 1966 and 1982, a triple DPT vaccine was studied in France in 1,871 infants between the ages of 3 and 5 months. The study covered tolerance and serological efficacy of two immunization schedules using 2 or 3 initial injections. Computerized analysis of the 877 complete files showed satisfactory tolerance of this association and the serological efficacy of 2 initial doses of tetanus and diphtheria vaccines. Pertussis immunization is only effective after 3 injections. The presence of maternal antibodies when the first injection is given only decreases the immune response of diphtheria vaccine.

Antibodies, Viral↗
PubMed1987

[Vaccination and malnutrition].

Although a depressed cellular immunity may be present in proteino-energetic malnutrition, humoral immunity is usually normal. Except for vaccines acting through a stimulation of cellular immunity like BCG, infants and children with malnutrition show a normal immune response to immunisations without a majoration of the side-effects. Consequently there is no contra-indication to immunisations in malnourished infants and children. Early immunisation before the age of one should be encouraged in countries where malnutrition in children is frequent.

Antibody Formation↗
PubMed1985

Pertussis immunization of infants using a new combined DTP-polio vaccine.

As part of the evaluation of a new combined Diphtheria-Tetanus-Pertussis-Poliomyelitis (DTP-Polio) inactivated vaccine, the pertussis agglutinin response was studied in 62 infants, two to three months old. Each dose of vaccine combined these antigens in a 0.5 ml volume, and contained at least four International Protective Units of pertussis antigen adsorbed on aluminium hydroxide. Infants were vaccinated with three doses of DTP-Polio vaccine at two month intervals. Pertussis agglutinin determinations showed a satisfactory response after two DTP-Polio vaccine doses. Although higher agglutinin titres were apparent after three doses than after two, no significant difference was observed in the seroconversion rate after two or three doses (88.8% and 96.3% respectively). The DTP-Polio vaccine would thus seem suitable for use in a two-dose primary immunization schedule against pertussis.

Agglutinins↗
PubMed1981

[Cutaneous delayed hypersensitivity in a French reference population using the cell-mediated immunity multitest device].

The authors present a disposable device which may be used for skin tests studying delayed cellular hypersensitivity with 7 antigens and a glycerin control. With the aim of more objective evaluation of the results, they suggest the establishment of a score taking into account the number of positive reactions and the degree of the reactions. Finally, they describe the results of a large multicentre study involving 830 subjects considered to be healthy and divided into 4 groups according to the response to the tests.

Adolescent↗
PubMed1980

Intradermal immunization with rabies vaccine. Inactivated Wistar strain cultivated in human diploid cells.

We report a comparative study of the Mérieux Institute's inactivated rabies vaccine administered intradermally or subcutaneously. Vaccine safety was satisfactory, with only minor local and generalized reactions. Serological effectiveness was outstanding: all of those who had been seronegative became seropositive following either two intradermal or subcutaneous injections given one month apart. A comparison of the intradermal and subcutaneous routes demonstrated several important points. Antibody titers developing after subcutaneous immunization were greater than after intradermal immunization. The kinetics of antibody development during primary immunization were parallel in the two immunization protocols. Eleven months after primary immunization, subcutaneous administration of a booster dose of vaccine resulted in a titer elevation 1.86-fold greater than that in intradermal administration. Each of these levels indicated good serological response.

Adult↗
PubMed1978

Combination of attenuated measles vaccine (Schwarz) with meningococcus A and A + C vaccine.

There is an obvious interest in a combined meningococcus-measles vaccine since the two diseases are widespread and serious in Third World countries among children under five years of age. The purpose of our study was to show the safety and effectiveness of such a combined preparation. The study covered 110 children between 8 months and 4 years of age who were followed systematically in a maternal child health center in the Paris area. Only 93 of them were checked before and after the immunization. The serologic titrations by the hemagglutination assay (IHA) for measles, and by radioimmunological assay (RIA) for meningococcus A and C showed that the Schwarz strain measles vaccine combined with meningococcus A or the association A+C does not interfere with the increase of A or C titers. 100% of the children showed a seroconversion equal to or less than 2 micrograms per ml, in the case of meningococcus A, as well as for C, regardless of age. Furthermore, 88% of the subjects showed a titer greater than or equal to 4 micrograms for the meningococcus A and 79% for C. On the other hand, meningococcus A or the association A+C seem to depress measles vaccine activity. Nevertheless, more than 80% of the children tested showed seroconversion when the measles vaccine was combined with meningococcus A, and only 69% when combined with meningococcus A and C.

Age Factors↗
PubMed1978

[Results of preventive rabies vaccination with a concentrated vaccine of the PM/WI38-1503-3M rabies strain cultured on human diploid cells. Preparation of mixed antirabies-antitetanus hyperimmune immunoglobulin by plasmapheresis of blood taken from vaccinated veterinary students].

Many thousands of people in France and abroad have already benefited from preventive rabies vaccination by means of a vaccine obtained from culture on human diploid cells, perfected ten years ago by R. Lang, the Institut Mérieux and the Wistar Institute. In addition to being well tolerated, the serological efficacy of this vaccine is such that 100% of the vaccines observed had a seroconversion after only two injections at an interval of one month. However, a booster dose should be given 6 to 12 months after the first injection, and a further booster 3 to 5 years later or on request in case of known contamination. These boosters, combined with an anti-tetanus booster, induce such high antibody titers--between 10-100 and even 1000 I.U./ml--that it is easy to obtain substantial batches of combined anti-rabies and anti-tetanus immunoglobulin from a small number of volunteers. The complete efficacy of this new vaccine reduces the number of systematic post-vaccinal serologic controls and its innocuity is such that an extended preventive vaccination programme may be carried out, for instance in the case of children living in areas known to be dangerous.

Adult↗