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At least 289 records · Page 16Linked to original sources
PubMed1982

Cross protection in infections due to Schistosoma mansoni using tegument antigens of Fasciola hepatica.

Immunity to infection due to Schistosoma mansoni was induced in CBA/J mice by using a tegument antigen from Fasciola hepatica worms. Multiple immunizations resulted in up to 83% higher worm-burden reductions than did single immunizations. The vaccine also had an adverse effect on the fecundity of female schistosome worms, which resulted in a lower number of eggs per worm pair recovered from the livers of infected mice. Mice immunized once with tegument antigens of F. hepatica survived lethal doses of S. mansoni cercariae for longer periods than did control mice. These results--lowered worm-burden recoveries, lower egg burdens per worm pairs resulting in lesser numbers of granulomatous lesions, and longer survival times--in immunized mice suggest that protection against infection due to S. mansoni is possible using soluble antigens as vaccines.

Animals↗
PubMed2001

Induction of cross-protection in mice against dolphin Erysipelothrix rhusiopathiae isolates with a swine commercial vaccine.

Erysipelothrix rhusiopathiae is well known to cause disease in dolphins. This disease occurs either in an peracute way, leading to mortality even before clinical signs are observed or in a sub-acute way, characterized by rhomboidal skin lesions, that can be treated with penicillin or its derivatives. Commercial swine vaccines, containing inactivated serotype 2 strains, are currently used for vaccination but it is not known whether these vaccines induce protection against E. rhusiopathiae isolates from dolphins. In the present study, it was demonstrated in a mouse model that vaccination with a commercial swine vaccine (Eurovac Ery, Eurovet, Belgium) containing inactivated serotype 2 E. rhusiopathiae strains induced protection against challenge with three E. rhusiopathiae isolates from dolphins. The duration of the protection varied, depending on the challenging isolate, between 8 and >23 weeks. There was however no positive correlation between the amount of antibodies at the moment of challenge and the observed protection. In conclusion, vaccination trials in mice indicate that commercial serotype 2 swine Erysipelothrix vaccines induce protection against erysipelas caused by dolphin pathogenic isolates.

Animals↗
PubMed2000

Cross-protection and antigen expression by chicken embryo-grown Pasteurella multocida in chickens.

The growth of Pasteurella multocida strain X-73 (serotype 1) and P-1059 (serotype 3) in vivo instead of in vitro resulted in the expression of additional antigens, as revealed by SDS-PAGE profile and western blotting of the outer membrane detergent-insoluble fraction (DIF-OM). Minor protein bands ranging from 58-138 kDa were expressed by both strains; major bands ranging from 35-64 and 35-43 kDa were expressed by X-73 and P-1059, respectively. Antigens at 35-39 kDa were dense and dominant. Treatment of DIF-OM from both strains with sodium periodate and proteinase K, but not with trypsin, reduced ELISA reactivity; this suggested that DIF-OM was composed of glycoprotein. Western blotting with heterologous antisera demonstrated antigenic cross-reactivity between strains X-73 and P-1059 grown in vivo. Inactivated vaccine prepared from X-73 grown in vivo protected chickens against challenge with X-73, P-1059 and strain P-1662 (serotype 4); a similar vaccine prepared from in-vitro culture, however, protected only against the homologous serotype. Moreover, antiserum against X-73 grown in vivo but not against the same strain grown in vitro gave considerable passive protection against challenge with the heterologous strains P-1059 and P-1662.

Animals↗
PubMedDate not supplied

Serologic and cross-protection studies with several infectious bronchitis virus isolates from Delmarva-reared broiler chickens.

Five isolates, from broiler-type chickens, capable of causing acute respiratory disease were identified as infectious bronchitis virus (IBV). The agar-gel precipitin (AGP) test was effective in identifying the isolates as IBV. Virus-neutralization (VN) and cross-challenge tests indicated two of the isolates to be Massachusetts types and one to be a JMK type. The remaining isolates were different from strains normally encountered in chickens reared on the Delmarva Peninsula. One isolate, although serologically similar to the Connecticut strain, was able to infect Connecticut-virus-immune chickens. Another isolate was similar to Arkansas 99, a strain not previously reported in Delmarva.

Animals↗
PubMed1986

Strong biotype and serotype cross-protective antibacterial and antitoxic immunity in rabbits after cholera infection.

We studied whether immunity evoked by infection with classical or El Tor V. cholerae 01 organisms in rabbits (the RITARD model) also gives protection against cholera caused by V. cholerae of heterologous biotype as well as serotype, and whether such protection is antibacterial and/or antitoxic. A primary infection with a classical Ogawa or El Tor Inaba strain resulted in intestinal colonization and diarrheal disease in a dose-related manner though the El Tor strain was more virulent. As few as 10(3) El Tor organisms gave disease in more than 90% of the rabbits as compared to 10(9) classical organisms (ED90); the El Tor strain also gave rise to diarrhea with earlier onset and of greater severity and longer duration. The primary infection induced strong protective immunity against later challenge with either the homologous or the heterologous strain in doses that corresponded to 1,000 x ED90. Protection was associated with marked inhibition of colonization, and when rabbits convalescing from cholera infection were challenged with graded doses of bacteria or purified toxin in ligated intestinal loops significant antibacterial as well as antitoxic immunity was evident. Titer rises in serum vibriocidal and anti-lipopolysaccharide antibodies were similar after infection with either strain, whilst antitoxin titer rises were more marked after El Tor infection. During infection V. cholerae 01 organisms seem to express protective antigens that stimulate immunity which extends across both biotype and serotype barriers.

Animals↗
PubMed1979

Cross-protection against Salmonella enteritidis infection in mice. III. Delayed hypersensitivity reaction and clearance of the challenge organism.

Mice were immunized with live vaccines and with live vaccines with complete adjuvant incorporating Salmonella enteritidis, Salmonella typhi-murium, Salmonella gallinarum or Salmonella pullorum. On the 21st day after vacination, the hypersensitivity reactions elicited by the mice to extracts of the challenge organism (S. enteritidis 5694 SMR) were assessed. The degree of delayed hypersensitivity reaction was compared with the level of protection induced by the vaccine. The role in protection of delayed hypersensitivity is discussed. Clearance of the challenge organism from the liver of previously vaccinated and unvaccinated mice was assessed quantitatively.

Adjuvants, Immunologic↗
PubMed1997

Cross protective immunity conferred by a marker-free aroA mutant of Pasteurella multocida.

The aroA gene from Pasteurella multocida serotype A:1 (X-73) was cloned by complementation of the Escherichia coli aroA mutant AB2829 with a DNA library constructed in pUC18. The cloned aroA gene was inactivated by deletion of a 300 bp internal sequence and reintroduced by homologous recombination into the chromosome of X-73 and P-1059 (serotype A:3) using a Pasteurella-E. coli shuttle vector pPBA1100. By subjecting the transformed cells to repeated subculturing in the presence of antibiotic selection coupled with auxotrophic enrichment, marker-free aroA mutants of X-73 and of P-1059 were isolated and designated PMP1 and PMP3, respectively. PMP1 and PMP3 were highly attenuated and capable of conferring complete protection against subsequent lethal challenge infection in a mouse model. Moreover, PMP3-immunized mice were protected against heterologous challenge infection with serotype A:1 or A:4.

3-Phosphoshikimate 1-Carboxyvinyltransferase↗
PubMed1979

Cross-protection against Salmonella enteritidis infection in mice.

Mice were immunized subcutaneously with live vaccines and live vaccines with complete adjuvant incorporating Salmonella enteritidis Se 795, Salmonella typhi-murium M206, Salmonella gallinarum 9R or Salmonella pullorum Sp223. They were challenged along with unvaccinated controls with 100 LD50 of virulent S. enteritidis 5694 SMR subcutaneously on the 21st day post-vaccination. The humoral immune response was studied by assessing the sequential level of agglutinins, complete and incomplete somatic antibodies, opsonophagocytic antibodies, cytophilic antibodies and bactericidal antibodies before and after challenge. The level of these antibodies and the protection afforded by the particular vaccine is correlated and the possible involvement of a humoral mechanism is discussed.

Adjuvants, Immunologic↗
PubMed2006

Cross-protection against Marburg virus strains by using a live, attenuated recombinant vaccine.

Marburg virus (MARV) has been associated with sporadic episodes of hemorrhagic fever, including a recent highly publicized outbreak in Angola that produced severe disease and significant mortality in infected patients. MARV is also considered to have potential as a biological weapon. Recently, we reported the development of a promising attenuated, replication-competent vaccine against MARV based on recombinant vesicular stomatitis virus (VSV) expressing the glycoprotein of the Musoke strain of MARV (VSVDeltaG/MARVGP-Musoke). We used this vaccine to demonstrate complete protection of cynomolgus monkeys against a homologous MARV challenge. While these results are highly encouraging, an effective vaccine would need to confer protection against all relevant strains of MARV. Here, we evaluated the protective efficacy of the VSVDeltaG/MARVGP-Musoke vaccine against two heterologous MARV strains, the seemingly more pathogenic Angola strain and the more distantly related Ravn strain. In this study, seven cynomolgus monkeys were vaccinated with the VSVDeltaG/MARVGP-Musoke vector. Three of these animals were challenged with the Angola strain, three with the Ravn strain, and a single animal with the Musoke strain of MARV. Two animals served as controls and were each injected with a nonspecific VSV vector; these controls were challenged with the Angola and Ravn strains, respectively. Both controls succumbed to challenge by day 8. However, none of the specifically vaccinated animals showed any evidence of illness either from the vaccination or from the MARV challenges and all of these animals survived. These data suggest that the VSVDeltaG/MARVGP-Musoke vaccine should be sufficient to protect against all known MARV strains.

Animals↗
PubMed2005

Toxoplasma gondii: partial cross-protection among several strains of the parasite against congenital transmission in a rat model.

Rats were immunized with cysts of two Toxoplasma strains or with RH strain tachyzoites prior to pregnancy. The litters of the 13 rats that received homologous challenges with cysts during pregnancy, were all protected, whereas of 173 rats that received heterologous challenges with cysts or oocysts, only 21 protected their litters. 38.3 and 17% of rats immunized with the RH and with complete strains respectively, and 57% of control rats challenged with cysts, transmitted the infection congenitally. The percentages when similar groups were challenged with oocysts, were 33.3, 48.2, and 56.2%, respectively. Immunization with cysts did not completely protect against challenge with oocysts, even if the same strain was used. The divergence of these results from the complete protection against congenital toxoplasmosis observed in immune women and ewes, might be due to the use of excessive challenge doses in the model.

Animals↗
PubMedDate not supplied

Haemophilus pleuropneumoniae serotypes--cross protection experiments.

Pigs vaccinated with a killed 6-hour culture of Haemophilus pleuropneumoniae serotype 2 with Freund's incomplete adjuvant were not protected against challenge with serotypes 1, 5, 6 or 8. Equivalent results were obtained when pigs were vaccinated with serotypes 4 or 5 and challenged with serotype 2. In earlier studies of immunity induced by intranasal immunization with live H. pleuropneumoniae organisms, it was clearly shown that intranasal inoculation with one serotype of H. pleuropneumoniae would induce a strong immunity to both homologous and heterologous serotypes (Nielsen 1979). The present study has shown that cross immunity is not obtained with parenteral immunization. The results strongly suggest that the immune response of the pig to parenteral vaccination is different from the response seen after natural infection, and indicate that an important part of the defence mechanism against H. pleuropneumoniae infection is a local immune-barrier which is effective in preventing the bacterium from penetrating the mucosa. In earlier vaccination experiments 90 per cent of vaccinates were protected against homologous challenge (Nielsen 1976). In the present work a vaccine containing serotypes 1 through 6 was fully protective against serotypes 2 and 3 and also against serotype 8, which shares antigenic determinants with serotypes 3 and 6. These results indicate that the protection obtained by parenteral immunization is serotype-specific. Vaccines must therefore contain the serotypes existing in the swine population.

Animals↗
PubMed1978

Studies on cross protection induced in calves by rotaviruses of calves, children and foals.

Inoculation at birth with a live attenuated strain of a bovine rotavirus isolated in the USA (scourvax-reo) induced protection in five gnotobiotic calves seven to 21 days later against a UK isolate of pathogenic bovine rotavirus. However, no protection was induced in three calves challenged three to five days after vaccination. There was a close antigenic relationship demonstrated between the two bovine rotavirus isolates. In contrast only one of three gnotobiotic calves inoculated with foal rotavirus, and one of three with human rotavirus, were protected against bovine rotavirus challenge. Protection in these two calves correlated with high heterologous immunofluorescent antibody titre (320 or greater), although the neutralising antibody titres was less than 20.

Animals↗
PubMed1977

Matrix protein from influenza A virus and its role in cross-protection in mice.

The matrix (M) protein of influenza A virus, one of the two group-specific internal proteins of the virion, was isolated in a pure form, and its immunogenicity was stable to heating at 100 degrees C for 2 min. Mice immunized with isolated M protein in complete Freund adjuvant and subsequently infected with influenza virus cleared virus more rapidly from their lungs than did unimmunized mice. Despite the rapid clearance of virus, the mice developed pneumonia that was at least as severe as in unimmunized mice. Preliminary studies suggest that the rapid clearance of influenza virus from the lungs of mice immunized with M protein may be initiated by a cell-mediated rather than a humoral response. The mechanism by which a cross-reactive internal virion protein can initiate clearance of the different subtypes of influenza is not clear. Perhaps the M protein is exposed on the surface of the virus-infected cell and is responsible for the cross-reactivity at the cytotoxic T-cell level recently detected between influenza A virus subtypes.

Animals↗
PubMed1984

Ecological studies of Yersinia enterocolitica. III. Cross-protection against fecal excretion between Y. enterocolitica serovars 3 and 5.27 in pigs.

Yersinia enterocolitica biovar 4 serovar 3 and biovar 2 serovar 5.27 failed to establish in the intestines of pigs when challenged with the homologous or heterologous strains. After inoculation, the serum O-agglutinin titers were 1/10 or less and were not boosted by challenge with either serovar. Y. enterocolitica were not recovered in any specimens at the time of slaughter.

Agglutinins↗