RESUMO
In many animal species, females select a mate on the basis of the expression of secondary sexual traits. A prevalent theory suggests that male ornaments are reliable indicators of immunocompetence, because the cost of immune function prevents cheating. However, sexual signalling is a component of male reproductive effort, and an immune challenge may also alter his perceived future prospects and hence signalling effort. In this study, blue-footed booby males (Sula nebouxii) were inoculated with a diphtheria-tetanus vaccine during courtship to investigate the consequences of mounting an immune response on signalling effort. We found that, after this immune challenge, on average, males increased their signalling effort but lost more body mass compared with control males. Importantly, vaccination affected the partner's reproductive decisions: compared with control females, females paired with vaccinated males laid eggs earlier and increased clutch volume in pairs that laid early. Overall, our results suggest that blue-footed booby males invest more in sexual signals when future breeding opportunities are at risk, eliciting a greater reproductive investment by their partners. Increased signalling effort by infected individuals may contrast the idea of sexual ornaments as signals of infection status.
Assuntos
Comunicação Animal , Aves/imunologia , Aves/fisiologia , Preferência de Acasalamento Animal/fisiologia , Caracteres Sexuais , Animais , Peso Corporal , Tamanho da Ninhada , Vacina contra Difteria e Tétano/imunologia , Feminino , Modelos Lineares , Masculino , México , Pigmentação/fisiologiaRESUMO
Tetanus and diphtheria vaccines are of special concern in adolescents because boosters are necessary for adequate maintenance of protection and are often omitted. We assessed serum levels of tetanus and diphtheria antibodies in adolescents and their association with vaccination status. From May to October 2001, we evaluated the vaccination records of 208 adolescents aged 10 to 20 years in São Paulo, Brazil. Antibodies to tetanus and diphtheria were detected using double-antigen ELISA and vaccination records were analyzed according to the guidelines of the Brazilian National Immunization Program. All adolescents had received complete primary vaccinations against tetanus and diphtheria, but 23.1% of them had not received a booster dose in the last 10 years. All adolescents were immune to tetanus and 88.9% were fully protected (antibodies (3)0.1 IU/mL). One individual (0.5%) was non-immune to diphtheria and 86% were fully protected against the disease. Adolescents with up-to-date vaccination records had higher antibody levels than those with not up-to-date records for tetanus (0.763 vs 0.239 IU/mL, t-test: P < 0.0001) and diphtheria (0.366 vs 0.233 IU/mL, t-test: P = 0.014). Full immunity against tetanus (antibodies (3)0.1 IU/mL) was higher among individuals with up-to-date vaccination (93.1%) when compared to those with not up-to-date records (75%, Fisher's exact test: P = 0.001). All adolescents had received basic immunization in childhood and were protected against tetanus and diphtheria. However, these data indicate that more emphasis should be placed on the tetanus-diphtheria booster in order to avoid a decay in antibody levels.
Assuntos
Anticorpos Antibacterianos/sangue , Vacina contra Difteria e Tétano/imunologia , Difteria/prevenção & controle , Tétano/prevenção & controle , Adolescente , Adulto , Anticorpos Antibacterianos/imunologia , Brasil , Criança , Difteria/imunologia , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Masculino , Tétano/imunologiaRESUMO
Tetanus and diphtheria vaccines are of special concern in adolescents because boosters are necessary for adequate maintenance of protection and are often omitted. We assessed serum levels of tetanus and diphtheria antibodies in adolescents and their association with vaccination status. From May to October 2001, we evaluated the vaccination records of 208 adolescents aged 10 to 20 years in São Paulo, Brazil. Antibodies to tetanus and diphtheria were detected using double-antigen ELISA and vaccination records were analyzed according to the guidelines of the Brazilian National Immunization Program. All adolescents had received complete primary vaccinations against tetanus and diphtheria, but 23.1 percent of them had not received a booster dose in the last 10 years. All adolescents were immune to tetanus and 88.9 percent were fully protected (antibodies ³0.1 IU/mL). One individual (0.5 percent) was non-immune to diphtheria and 86 percent were fully protected against the disease. Adolescents with up-to-date vaccination records had higher antibody levels than those with not up-to-date records for tetanus (0.763 vs 0.239 IU/mL, t-test: P < 0.0001) and diphtheria (0.366 vs 0.233 IU/mL, t-test: P = 0.014). Full immunity against tetanus (antibodies ³0.1 IU/mL) was higher among individuals with up-to-date vaccination (93.1 percent) when compared to those with not up-to-date records (75 percent, Fisher's exact test: P = 0.001). All adolescents had received basic immunization in childhood and were protected against tetanus and diphtheria. However, these data indicate that more emphasis should be placed on the tetanus-diphtheria booster in order to avoid a decay in antibody levels.
Assuntos
Humanos , Masculino , Feminino , Criança , Adolescente , Adulto , Anticorpos Antibacterianos/sangue , Vacina contra Difteria e Tétano/imunologia , Difteria/prevenção & controle , Tétano/prevenção & controle , Anticorpos Antibacterianos/imunologia , Brasil , Difteria/imunologia , Ensaio de Imunoadsorção Enzimática , Tétano/imunologiaRESUMO
A method for the screening of tetanus and diphtheria antibodies in serum using anatoxin (inactivated toxin) instead of toxin was developed as an alternative to the in vivo toxin neutralization assay based on the toxin-binding inhibition test (TOBI test). In this study, the serum titers (values between 1.0 and 19.5 IU) measured by a modified TOBI test (Modi-TOBI test) and toxin neutralization assays were correlated (P < 0.0001). Titers of tetanus or diphtheria antibodies were evaluated in serum samples from guinea pigs immunized with tetanus toxoid, diphtheria-tetanus or triple vaccine. For the Modi-TOBI test, after blocking the microtiter plates, standard tetanus or diphtheria antitoxin and different concentrations of guinea pig sera were incubated with the respective anatoxin. Twelve hours later, these samples were transferred to a plate previously coated with tetanus or diphtheria antitoxin to bind the remaining anatoxin. The anatoxin was then detected using a peroxidase-labeled tetanus or diphtheria antitoxin. Serum titers were calculated using a linear regression plot of the results for the corresponding standard antitoxin. For the toxin neutralization assay, L+/10/50 doses of either toxin combined with different concentrations of serum samples were inoculated into mice for anti-tetanus detection, or in guinea pigs for anti-diphtheria detection. Both assays were suitable for determining wide ranges of antitoxin levels. The linear regression plots showed high correlation coefficients for tetanus (r(2) = 0.95, P < 0.0001) and for diphtheria (r(2) = 0.93, P < 0.0001) between the in vitro and the in vivo assays. The standardized method is appropriate for evaluating titers of neutralizing antibodies, thus permitting the in vitro control of serum antitoxin levels.
Assuntos
Antitoxina Diftérica/sangue , Vacina contra Difteria e Tétano/imunologia , Vacina contra Difteria, Tétano e Coqueluche/imunologia , Antitoxina Tetânica/sangue , Animais , Antitoxina Diftérica/imunologia , Feminino , Cobaias , Masculino , Camundongos , Testes de Neutralização/métodos , Padrões de Referência , Reprodutibilidade dos Testes , Antitoxina Tetânica/imunologiaRESUMO
A method for the screening of tetanus and diphtheria antibodies in serum using anatoxin (inactivated toxin) instead of toxin was developed as an alternative to the in vivo toxin neutralization assay based on the toxin-binding inhibition test (TOBI test). In this study, the serum titers (values between 1.0 and 19.5 IU) measured by a modified TOBI test (Modi-TOBI test) and toxin neutralization assays were correlated (P < 0.0001). Titers of tetanus or diphtheria antibodies were evaluated in serum samples from guinea pigs immunized with tetanus toxoid, diphtheria-tetanus or triple vaccine. For the Modi-TOBI test, after blocking the microtiter plates, standard tetanus or diphtheria antitoxin and different concentrations of guinea pig sera were incubated with the respective anatoxin. Twelve hours later, these samples were transferred to a plate previously coated with tetanus or diphtheria antitoxin to bind the remaining anatoxin. The anatoxin was then detected using a peroxidase-labeled tetanus or diphtheria antitoxin. Serum titers were calculated using a linear regression plot of the results for the corresponding standard antitoxin. For the toxin neutralization assay, L+/10/50 doses of either toxin combined with different concentrations of serum samples were inoculated into mice for anti-tetanus detection, or in guinea pigs for anti-diphtheria detection. Both assays were suitable for determining wide ranges of antitoxin levels. The linear regression plots showed high correlation coefficients for tetanus (r² = 0.95, P < 0.0001) and for diphtheria (r² = 0.93, P < 0.0001) between the in vitro and the in vivo assays. The standardized method is appropriate for evaluating titers of neutralizing antibodies, thus permitting the in vitro control of serum antitoxin levels.
Assuntos
Animais , Masculino , Feminino , Cobaias , Camundongos , Antitoxina Diftérica/análise , Vacina contra Difteria e Tétano/imunologia , Vacina contra Difteria, Tétano e Coqueluche/imunologia , Antitoxina Tetânica/análise , Antitoxina Diftérica/imunologia , Testes de Neutralização/métodos , Padrões de Referência , Reprodutibilidade dos Testes , Antitoxina Tetânica/imunologiaRESUMO
Epidemiological data regarding tetanus and diphtheria immunity in elderly people in Brazil are scarce. During the First National Immunization Campaign for the Elderly in Brazil in April 1999, 98 individuals (median age: 84 years) received one tetanus-dyphtheria (Td) vaccine dose (Butantan Institute, lot number 9808079/G). Inclusion criteria were elderly individuals without a history of severe immunosuppressive disease, acute infectious disease or use of immunomodulators. Blood samples were collected immediately before the vaccine and 30 days later. Serum was separated and stored at -20 degrees C until analysis. Tetanus and diphtheria antibodies were measured by the double-antigen ELISA test. Tetanus and diphtheria antibody concentrations lower than 0.01 IU/mL were considered to indicate the absence of protection, between 0.01 and 0.09 IU/mL were considered to indicate basic immunity, and values of 0.1 IU/mL or higher were considered to indicate full protection. Before vaccination, 18% of the individuals were susceptible to diphtheria and 94% were susceptible to tetanus. After one Td dose, 78% became fully immune to diphtheria, 13% attained basic immunity, and 9% were still susceptible to the disease. In contrast, 79% remained susceptible to tetanus, 4% had basic immunity and 17% were fully immune. Although one Td dose increases immunity to diphtheria in many elderly people who live in Brazil, a complete vaccination series appears to be necessary for the prevention of tetanus.
Assuntos
Anticorpos Antibacterianos/sangue , Vacina contra Difteria e Tétano/imunologia , Difteria/prevenção & controle , Tétano/prevenção & controle , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antibacterianos/imunologia , Brasil , Difteria/imunologia , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Masculino , Tétano/imunologiaRESUMO
Epidemiological data regarding tetanus and diphtheria immunity in elderly people in Brazil are scarce. During the First National Immunization Campaign for the Elderly in Brazil in April 1999, 98 individuals (median age: 84 years) received one tetanus-dyphtheria (Td) vaccine dose (Butantan Institute, lot number 9808079/G). Inclusion criteria were elderly individuals without a history of severe immunosuppressive disease, acute infectious disease or use of immunomodulators. Blood samples were collected immediately before the vaccine and 30 days later. Serum was separated and stored at -20°C until analysis. Tetanus and diphtheria antibodies were measured by the double-antigen ELISA test. Tetanus and diphtheria antibody concentrations lower than 0.01 IU/mL were considered to indicate the absence of protection, between 0.01 and 0.09 IU/mL were considered to indicate basic immunity, and values of 0.1 IU/mL or higher were considered to indicate full protection. Before vaccination, 18 percent of the individuals were susceptible to diphtheria and 94 percent were susceptible to tetanus. After one Td dose, 78 percent became fully immune to diphtheria, 13 percent attained basic immunity, and 9 percent were still susceptible to the disease. In contrast, 79 percent remained susceptible to tetanus, 4 percent had basic immunity and 17 percent were fully immune. Although one Td dose increases immunity to diphtheria in many elderly people who live in Brazil, a complete vaccination series appears to be necessary for the prevention of tetanus.
Assuntos
Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Anticorpos Antibacterianos/sangue , Vacina contra Difteria e Tétano/imunologia , Difteria/prevenção & controle , Tétano/prevenção & controle , Anticorpos Antibacterianos/imunologia , Brasil , Difteria/imunologia , Ensaio de Imunoadsorção Enzimática , Tétano/imunologiaRESUMO
In a previous study, using BALB/c mice, we found that while diphtheria (D), tetanus (T) and whooping cough (Pw, whole-cell Bordetella pertussis) immunization induces a Th1/Th2 tetanus response and memory T cells able to proliferate in response to in vitro stimulation with B. pertussis, DTPa immunization induces a Th2 tetanus immune response and no memory T cells that recognize B. pertussis as stimulus. Considering that a pro-inflammatory cytokine production is not necessary for protection against tetanus and therefore should be avoided, an alternative DTP immunization schedule with minimal Pw exposure was assessed in order to obtain a Th2 tetanus response and a Th1 pertussis response. BALB/c mice were primed with DT vaccine at day 0, with Pw vaccine at day 14 and boosted with DTPa vaccine at days 21 and 28. A control group was inoculated with saline. Antibodies against B. pertussis surface antigens, tetanus and diphtheria toxoids were produced by mice. Spleen cells stimulated in vitro with B. pertussis produced IL-6 and IFNgamma. Only IL-5 was produced by cells in response to tetanus toxoid stimulation. These results are in line with the low IgG1/IgG2a ratio for pertussis antibodies compared with those corresponding to tetanus and diphtheria. The immunization protocol presented herein succeeded in producing tetanus and pertussis immune responses of Th2 and Th1 type, respectively. In contrast to previous results obtained with DTPw immunization, no IL-12 production was observed. Our findings provide direct evidence that an immunization protocol with an interval of 14 days between DT and Pw primings, followed by DTPa boosters, can induce appropriate immune responses against DTP vaccine antigens.
Assuntos
Bordetella pertussis/imunologia , Vacina contra Difteria e Tétano/administração & dosagem , Vacinas contra Difteria, Tétano e Coqueluche Acelular/administração & dosagem , Vacina contra Coqueluche/administração & dosagem , Células Th1/imunologia , Células Th2/imunologia , Animais , Anticorpos Antibacterianos/sangue , Antígenos de Bactérias/imunologia , Vacina contra Difteria e Tétano/imunologia , Vacinas contra Difteria, Tétano e Coqueluche Acelular/imunologia , Esquemas de Imunização , Imunização Secundária , Imunoglobulina G/sangue , Interferon gama/análise , Interleucina-12/análise , Interleucina-5/análise , Interleucina-6/análise , Camundongos , Camundongos Endogâmicos BALB C , Vacina contra Coqueluche/imunologia , VacinaçãoRESUMO
Samples from 20 lots of diphtheria-tetanus (adult use dT) vaccine and from 20 lots of diphtheria-tetanus-pertussis (DTP) vaccine were used to standardize and validate the in vitro toxin binding inhibition (ToBI) test for the immunogenicity test of the tetanus component. The levels of tetanus antitoxin obtained by ToBI test were compared to those obtained using the toxin neutralization (TN) test in mice routinely employed to perform the quality control of the tetanus component in adsorbed vaccines. The results ranged from 1.8 to 3.5 IU/ml for dT and 2 to 4 IU/ml for DTP by ToBI test and 1.4 to 3 IU/ml for dT and 1.8 to 3.5 IU/ml for DTP by TN in mice. These results were significantly correlated. From this study, it is concluded that the ToBI test is an alternative to the in vivo neutralization procedure in the immunogenicity test of the tetanus component in adsorbed vaccines. A substantial refinement and a reduction in use of animals can be achieved.
Assuntos
Vacina contra Difteria e Tétano/imunologia , Vacina contra Difteria, Tétano e Coqueluche/imunologia , Antitoxina Tetânica/imunologia , Animais , Toxoide Diftérico , Cobaias , Camundongos , Camundongos Endogâmicos BALB C , Testes de Neutralização , Controle de Qualidade , Antitoxina Tetânica/sangue , Toxina Tetânica , Toxoide TetânicoRESUMO
Several factors are involved in the selective activation of Th1 or Th2 cells, such as different physical characteristics of antigens and the type of antigen-presenting cells involved in the immune response, among others. To study the influence of a particulate antigen on Th1/Th2 cell differentiation during the immune response to another antigen, we analysed the immune response to tetanus toxoid (soluble antigen) in BALB/c mice immunized with one of the three following vaccines: tetanus and diphtheria toxoids (DT), or DT associated with whole-cell Bordetella pertussis or its soluble antigens (DTPw and DTPa, respectively). Similar total antibody levels were observed for all vaccines. DT vaccine showed a higher IgG1/IgG2a ratio than the similar values observed for DTPw and DTPa vaccines. DT- and DTPa-primed spleen cells showed a Th2 (IL-5) profile while a Th1/Th2 (IFN gamma, IL-5) profile was observed for DTPw. IL-6 was only produced by DTPw-primed cells. Besides, IL-12 levels induced by DTPw were three times higher than the ones induced by both DT and DTPa. Our findings indicate that whole-cell B. pertussis priming modifies the tetanus immune response from Th2 to Th1/Th2 type probably via inflammatory mechanisms. In addition, in the light of conflicting reports regarding the mechanisms of protection induced by DTP vaccines, we studied the pertussis immune response. Only DTPw immunization generated memory T cells capable of proliferating with B. pertussis as an in vitro stimulus. Results might indicate that these cells may not play a key role in protecting against B. pertussis when the host is vaccinated with DTPa.