Methods of determination of toxicity of pertussis vaccine. 1. Change in the weight of the thymus gland and the spleen in mice after administration of pertussis vaccine]

Experiments were conducted on mice, strain NIH, line HSFS/N, immunized with pertussis vaccine. Determination of thymocyte pool proved to be a more sensitive method of detection of the stress effect of the vaccine than determination of the thymus weight. The test can be used for the elaboration of the method of assessment of the toxicity of pertussis preparations.     

Antigen-nonspecific suppression of the immune response in mice as affected by pertussis vaccine

A study was made of the suppressorgenic action of killed whole-cell pertussis vaccine prepared from B. pertussis strains 475 and 305. Thymic and splenic lymphocytes of CBA mice 3-7 days following intraperitoneal or intravenous inoculation of pertussis vaccine were shown to inhibit in an antigen-nonspecific manner the plaque-forming cell (PFC) production in the adoptive transfer experiments. Suppression of graft-versus-host reaction was also observed, estimated by the survival of irradiated (CBA X C57BL/6) Fl mice, or by measuring the endogenous colony formation. Suppression-mediating cells were found to be susceptible to complement-dependent lysis by the anti-I-Jk alloantiserum against the specific marker of suppressor T cells, antigen I-J. Furthermore, thymocytes of pertussis vaccine-treated mice were shown to inhibit the endogenous colony formation in syngeneic mice irradiated in sublethal dose. Thus, B. pertussis vaccination of CBA mice resulted in appearance of suppressor T cells that exerted various inhibitory activities in several experimental test-systems.     

Examination of host defense factors responsible for experimental chronic respiratory tract infection caused by Klebsiella pneumoniae in mice.

We have studied the host defense factors that operate during the course of chronic respiratory tract infection caused by Klebsiella pneumoniae 27 in CBA/J mice. A large number of polymorphonuclear leukocytes (PMNs) rapidly infiltrated the alveolar spaces after infection. Treatment with cyclophosphamide (CY) before infection greatly reduced the infiltration of PMNs and caused an increase in bacterial counts. CY treatment of mice in the chronic phase also caused bacterial proliferation in the lungs. The administration of a high titer immune serum efficiently reduced the bacterial counts in the lungs during the early phase but not during the chronic phase. The proliferation of bacteria induced by CY treatment was not suppressed by the administration of the immune serum in either phase. When the mice were exposed to an aerosol containing Pseudomonas aeruginosa P9 in the chronic phase, the organisms from the secondary infection were eliminated from the lungs in the same manner as in the case of primary infection with P. aeruginosa. Thus, PMNs seem to play an important role in the suppression of bacterial proliferation in the early and chronic phases, and the specific antibody might have a supplementary effect on the defensive action of PMNs in the chronic phase. It is also presumed that the bacteria in the chronic phase of infection are sequestered at sites hardly accessible to PMNs.     

Polymyxin B suppresses the stimulating action of pertussis vaccine on hematopoiesis in mice

The injection of killed whole-cell pertussis vaccine (PV), prepared from formulated Bordetella pertussis strains 5574 and 305, into mice was shown to produce a stimulating effect on hematopoiesis. This effect was manifested by an increase in the number of endogenic colonies developing in the spleen of mice on days 5 and 9 after their irradiation in a sublethal dose, by the sharp stimulation of the proliferative activity of splenic colony-forming units (CFUs) originating in the bone marrow and by the elevated CFUs level in the peripheral blood. The preliminary incubation of whole-cell PV with polymyxin B, cationic polypeptide selectively reacting with the lipid A moiety of lipopolysaccharide (LPS), led to a sharp decrease in the above-mentioned manifestations of hematopoietic effect of the vaccine, while incubation with cetavlon interacting with the polysaccharide moiety of LPS produced practically no effect on the capacity of the vaccine for stimulating hematopoiesis. The stimulating effect of whole-cell PV on hematopoiesis is supposedly due, to a great extent, to the lipid A moiety of LPS.     

Selective breeding to establish a standard mouse for pertussis vaccine bioassay: II. Bioresponses of mice susceptible and resistant to sensitization by pertussis vaccine HSF

Two lines of mice bred for their susceptibility and resistance to sensitization by the histamine sensitizing factor of Bordetella pertussis, and designated as HSFS/N and HSFR/N, respectively, are described and characterized after 14 generations of selective breeding. The lines were derived from the N:HIH(SW) mouse strain with the ultimate purpose of providing genetically uniform mice with predictable characteristics, that are easily immunized by pertussis vaccine and have low variability in their response. Mice of the HSFS/N line were more easily sensitized to HSF, more immunizable with pertussis vaccine, less susceptible to intra-cerebral challenge by B. pertussis and less susceptible to Escherichia coli endotoxin and histamine diphosphate toxicity than were HSFR/N mice. The two lines responded similarly in the mouse weight gain test and did not differ in serum histaminase levels or susceptibility to passive anaphylaxis.     

Increase in intradermal vascular permeability caused by pertussis toxin from Bordetella pertussis

Rabbits that were injected intradermally with pertussis toxin (PT), produced from Bordetella pertussis, showed slight edema and erythema at the injection sites, but not hemorrhage nor necrosis. The edema lesions were stained blue by the intravenous injection of Pontamine Sky Blue 6B dye, suggesting that PT caused increased vascular permeability, similarly to the permeability factor (PF) of cholera toxin. The reaction of the PF of PT could be determined by measuring the diameter of the blue area. The diameter of the blue area bore a good linear relationship to the logarithm of the dose of PT. The activity of the PF was neutralized by anti-PT rabbit serum. Detoxification of PT with formalin did not increase the vascular permeability, but reverted pertussis toxoid showed a PF reaction in proportion to the reverted leukocytosis-promoting and histamine-sensitizing activities of PT. The supernate of a Bordetella pertussis culture also induced a PF reaction and the reaction could be made clear by heating the supernate at 56 C for 30 min, but the supernate of Bordetella bronchiseptica did not induce the reaction at all.     

Consistency of Bordetella pertussis vaccine seed strains and potency of whole-cell pertussis vaccine still in use in Poland

In Poland, where the wP vaccine has been used since 1960, pertussis rates increased in the mid-1990s. In 2012, the rate of pertussis recognised by surveillance was unexpectedly found to be two-fold higher than in the previous decade. Quality measures on potency and vaccine working seeds were introduced, to confirm the possible impact of manufacturing inconsistency or potency lowering on the observed increase in pertussis. Shewhart charts on potency values for lots released between 2001 and 2013 did not reveal any significant fluctuations. Working seeds of three vaccine strains used within last decade for wP manufacturing belong to the PFGE group III and were highly related. According to PFGE and SDS-PAGE data, all vaccine strains were found consistent according profiling on the genomic and protein levels. According to the sequencing data, they harboured ptxA2, ptxC1, prn1, fim2-1, fim3-1, tcfA2, ptxP1 and were assigned as MLST-2 type. Other factors apart from vaccine manufacturing inconsistency might be responsible for the increase in pertussis noted in 2012 in Poland.     

Humoral factors of local and systemic immunity in the multiple peroral administration of a corpuscular pertussis vaccine

Multiple oral immunization with pertussis corpuscular vaccine was shown to lead to the considerable stimulation of local and systemic humoral immunity. The data on the titers of specific and normal secretory antibodies, on the levels of IgA in washings from the oral cavity, the small intestine and the lungs, on the titers of agglutinins and hemagglutinins in the blood serum, as well as on the morpho-functional transformation of the mucous membrane and the associated lymphoid tissue in the digestive tract, are presented in their dynamics. Specific pertussis antibodies in high titers were detected in both intestinal and pulmonary washings. The multiple administration of the vaccine did not produce pathological changes in internal organs.     

Prophylaxis of pertussis: development and use of acellular pertussis vaccine

Modern data substantiating the expediency of the use of acellular pertussis vaccine were analyzed. Serious postvaccinal complications caused by the action of the corpuscular pertussis component of adsorbed DPT vaccine served as the basis for the development of acellular pertussis vaccine (APV). During the period of 1990-1996 as many as 8 international field trials of the effectiveness of APV were carried out. The results of these trials and studies were evaluated in accordance with the unified programs and criteria. The vaccines under test differed by the composition of Bordetella pertussis purified antigens they contained, the methods of their purification and the detoxification of pertussis toxin. All tested APV, with the exception SKB-2, possessed pronounced prophylactic activity.     

Toxicity of Bordetella pertussis suspensions associated with the preparation of pertussis vaccine

The process of the detoxication of B. pertussis suspensions during their storage has a wave-like character and is determined by changes in the levels of the toxicity of the soluble and corpuscular fractions. Conditions facilitating the transition of toxic cellular products into the soluble state may lead to the increase of the toxic activity of pertussis vaccines.