New vaccines require potent adjuvants like AFPL1 and AFCo1.

Neisseria meningitidis B proteoliposome (AFPL1 when used as adjuvant) and its derivative-Cochleate (AFCo1) contain immunopotentiating and immunomodulating properties and delivery system capacities required for a good adjuvant. Additionally, they contain meningococcal protective antigens and permit packaging of other antigens and pathogen-associated molecular patterns (PAMP). Consequently, we hypothesized that they would function as good vaccine adjuvants for their own antigens and also for non-related antigens. AFPL1 is a detergent-extracted outer membrane vesicle of N. meningitidis B transformed into AFCo1 in calcium environment. Both are produced at Finlay Institute under good manufacture practices (GMP) conditions. We show their exceptional characteristics: combining in the same structure, the potentiator activity, polarizing agents and delivery system capacities; presenting multimeric protein copies; containing multiprotein composition and multi and synergistic PAMP components; acting with incorporated or co-administrated antigens; inducing type I IFN-gamma and IL-12 cytokines suggesting the stimulation of human plasmocytoid precursor and conventional dendritic cells, respectively, inducing a preferential Th1 immune response with TCD4(+), TCD8(+), cross-presentation and cytotoxic T-lymphocyte (CTL) in vivo responses; and functioning by parenteral and mucosal routes. AFPL1-AFCo1 protective protein constitutions permit per se their function as a vaccine. In addition to Phase IV Men BC vaccine, AFPL1 has ended the preclinical stage in an allergy vaccine and is concluding the preclinical stage of a nasal meningococcal vaccine. In conclusion, AFPL1 and AFCo1 induced signal 1, 2 and 3 polarizing to a Th1 (including CTL) response when they acted directly as vaccines or were used as adjuvants with incorporated or co-administered antigens by parenteral or mucosal routes. Both are very promising adjuvants.

[Standardization of the lethal dose 50% of Leptospira interrogans strains used in the control of the leptospirosis cuban vaccine for human use]. / Normalización de la dosis letal 50% de cepas de Leptospira interrogans utilizadas en el control de la vacuna antileptospirósica cubana para uso humano.

The LD50 of strains of L. interrogans used in the potency assay of the Cuban trivalent leptospiral vaccine intended for human use was standardized. The control of the leptospires content of the cultures by means of the adjusting dilution (10 to 12 leptospires per field) was introduced. That was the key of the standardization of the assay, since it guaranteed the reproducibility of the estimate of the LD50 value for each serogroup: 10(5.98) for canicola, 10(5.60) for icterohaemorrhagiae and 10(6.60) for pomona, with the following limits for an interval of 1 log10: 10(4.98)-10(6.98), 10(4.60)-10(6.60) and 10(5.49)-10(7.49), respectively; whereas for a 95% (+/- 2 SD) confidence interval the values were: 10(5.54)-10(6.19); 10(5.33)-10(5.75) and 10(6.35)-10(6.60), respectively. These values were lower than the previous ones, which means ever more reproducibility. The methodology described proved to be satisfactory for the standardization of the LD50 of the challenge strains and it could also be used for evaluating the virulence of other strains of L. interrogans, including those used for the vaccine production.

UltramicroELISA for measuring tetanus antitoxin in human sera.

This article describes a combination of methods--a solid-phase enzyme-linked immunosorbent assay (ELISA) combined with an ultramicroanalytical system (UMAS)--that can be used to measure tetanus antitoxin activity in human sera or plasma. The test, which is rapid and permits analysis of 78 samples of serum per reaction plate with a volume of 10 microL of diluted serum per sample, is proposed as an alternative to the traditional biologic assay in mice based on seroneutralization of a known dose of tetanus toxin. The study reported here compared these two procedures, using them both to evaluate 100 sera from the Clinical Laboratory of the General Calixto García Hospital in Havana, Cuba. The two sets of results showed a high degree of correlation (r = 0.99) when subjected to linear regression analysis (95% CI = 0.985-0.993). These and other findings indicate that the cheap and rapid ultramicroELISA method can perform certain tasks for which the slower and costlier traditional assay is not well suited, such as field evaluation of tetanus toxoid vaccines and identification of hyperimmune plasmas appropriate for use in producing specific antitetanus immunoglobulin.

[Ultramicro-ELISA for measuring tetanus antitoxin in human serum]. / UltramicroELISA para medir antitoxina tetánica en suero humano.

A solid-phase enzyme immunoassay (ELISA) for measuring tetanus antitoxin activity in human serum is described; the assay is based on a combination of the indirect method and ultramicro analysis. This rapid test, which has the capacity to analyze 78 blood samples per reagent plate (at a volume of 10 microL of diluted serum per sample), is proposed as an alternative to the traditional mouse bioassay system based on the neutralization of a known dose of tetanus toxin. Results from both tests showed a high correlation in the lineal regression analysis (r = 0.99; CI95%: 0.985 to 0.993). It is recommended that the ultramicro ELISA assay be used in the field to evaluate tetanus toxoid vaccines and to identify hyperimmune plasmas suitable for producing antitetanus immunoglobulin.