[Effect of atypical mycobacteria infections on BCG immunization in man (author's transl)]. / Effet des infections occultes par des mycobactéries atypiques sur l'hypersensibilité retardée à la tuberculine.

The influence of atypical mycobacteria infections on BCG responses was studied in 1,038 schoolchildren. A comparaison of the sizes of the scars and a study of control tuberculin tests 10 weeks later confirm the experimental results and suggest that there is a protective effect against tuberculosis induced by atypical mycobacteria.

[Development of an operational immunization programme (author's transl)]. / Comment rendre opérationnel un programme de vaccinations?

Following the severe 1974 W. H. O. warning, many countries want to develop an expanded programme of immunization during the period extending till 1990, to control 6 major diseases: diphtheria, tetanus, poliomyelitis, pertussis, measles and TB. No single programme can be proposed as the economic, epidemiological and structural problems differ according to countries and regions. C. Fillastre suggests a methodology to be used in the assessment of the initial situation with regard to existing epidemiological data, immunizations against the afore mentioned diseases, vaccines health structures (cold chain) and staff. The implementation of the supervision of material and staff and of an assessment system, allowing programme changes at any time on the basis of improvements achieved is mandatory.

[Vaccination and malnutrition]. / Vaccination et 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.

[Tetravalent diphtheria, tetanus, pertussis and inactivated poliomyelitis vaccine]. / Vaccination tétravalente diphtérique, tétanique, coquelucheuse et poliomyélitique inactivée.

Two hundred forty-nine infants were immunized after being randomly allocated to the classical Tetracoq vaccine or to inactivated poliomyelitis vaccines prepared on monkey kidney cells or on Vero-type continuous cell lines either mixed with DPT or placed in a 2-compartment syringe separating (by-pass) the polio vaccine from the DPT. The 3 preparations were well tolerated and led to a good immune response: the first after 3 injections, the second and third after the second injection.

[Comparative study of two dried intradermal BCG vaccines (author's transl)]. / Etude comparative de deux vaccins BCG secs intradermiques.

Two BCG vaccines prepared from the same strain were studied clinically in Indonesia and in France. The concentration in culturable particles was comparable. Observed differences in the Mantoux results are discussed. The French results, based on use in a temperate climate by a specialized team, on well nourished children, appear better than the Indonesian findings. Further steps should be undertaken to improve results in Indonesia.

The stability and immunogenicity of a dispersed-grown freeze-dried Pasteur BCG vaccine.

The level of antituberculous immunity seems to be related to the number of memory T cells induced. This may vary as a function of the multiplication and persistence of BCG in host tissues. The most important requirements for a BCG vaccine are, therefore, the immunogenicity of the strain, the high proportion of live to dead bacilli, and adequate dispersion and low levels of soluble antigens. The surface-grown Pasteur BCG vaccine contains a very high proportion of bacilli killed by ball-milling and freeze-drying. It also contains clumps and soluble antigens, all factors influencing cell-mediated immune processes and viability control. Therefore, several batches of vaccine were prepared on an industrial scale using one of the most immunogenic strains (French 1173 P2) and grown as dispersed bacilli by a modified cell type culture method. This method provided fully viable, well-dispersed vaccines which have a viability and heat stability superior to that of the classical surface-grown BCG. The immunogenicity was checked by multiplication and persistence in mouse organs and the skin reactivity and tuberculin hypersensitivity in guinea-pigs showed results comparable to those obtained with classical vaccine. Small-scale tests in children showed superior immunogenicity of the dispersed as opposed to the classical vaccine and there was no suppurative adenitis.

[20 years' use of the diphtheria-pertussis-tetanus vaccine]. / Vingt années d'utilisation du vaccin diphtérique-tétanique-coquelucheux (DTcoq).

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.

Clinical trial of concentrated inactivated polio vaccine in a simplified immunization program.

The aims of the trial were: 1) to verify the effectiveness of injectable polio vaccine (inactivated) combined with concentrated diphtheria and tetanus toxoid, in one or two injections given at an interval of 6 months; 2) to compare the killed polio vaccine with the oral vaccine which is recommended in the Ivory Coast program: 4 doses in 15 months. The effectiveness of the immunizations is judged by the serum antibody levels 8 to 12 weeks following immunization. The comparative study of 2 inactivated polio vaccines A and C with live oral vaccine showed the superiority of inactivated vaccine, which resulted in good seroconversion after a single dose. The increase in the serologic response is proportional to the antigenic mass since it appears that the concentration of vaccine C is double that of A.

Killed poliovirus antigen titration in humans.

To establish the antigen content of a killed poliovirus vaccine sufficiently potent to induce immunity with one or two doses and to establish a reference standard vaccine which has been tested under field conditions, a titration was carried out in infants to determine the amount of each of the three antigenic types of poliovirus vaccine required to induce seroconversion with a single dose. It has been observed that over a critical range of antigen concentration there is an essentially linear relationship between antibody response and quantity of antigen administered. More than 90 percent of the groups studied had detectable antibody after receiving single injections of 80, 8 and 64 D-antigen units of Types I, II and III, respectively. Four-fold less antigen for each of the three types was less effective. The implications of these findings for an efficient immunization procedure are discussed.

The use of jet-injectors in BCG vaccination.

In mass vaccination programmes, the jet-injection of vaccine may have considerable operational advantages over the classical techniques. The technical performance of two models of jet-injector, the Dermo-Jet and the Ped-O-Jet, in BCG vaccination was assessed in a number of studies which are reviewed by the authors. It is shown that the jet-injectors do not administer the full dose for which they are calibrated and that the size of the vaccination lesion varies more than after vaccination by syringe.By increasing the dosage considerably, the results of vaccination by jet-injection may be improved to a certain extent but the risk of unpleasant reactions is also increased.