Cloning of two putative Giardia lamblia glucosamine 6-phosphate isomerase genes only one of which is transcriptionally activated during encystment

Acellular pertussis vaccines provide protection against whooping cough with few adverse effects. Their introduction to routine immunisation programmes would be facilitated by their incorporation with other routinely administered vaccines. 262 infants were immunised with an acellular pertussis vaccine containing pertussis toxin and filamentous haemagglutinin, combined with diphtheria and tetanus toxoids. This vaccine was mixed with Haemophilus influenzae type b tetanus toxoid vaccine (PRP-T) so that infants received a single injection at age 2, 3 and 4 months. One month after the third dose the geometric mean titre of Hib IgG antibody was 0.48 microgram ml-1. Eighty-two percent of infants achieved a titre of 0.15 microgram ml-1, with only 27% achieving 1.0 microgram ml-1. This combination vaccine induced low Hib antibody responses when compared to other studies in which PRP-T was mixed with acellular or whole-cell pertussis vaccines. The combined vaccine did, however, appear to prime a subset of 35 infants for response to a fourth dose of PRP-T at 13 months of age, with a rise in GMT from 0.21 microgram ml-1 to 36.6 micrograms ml-1. These data have important implications for the introduction of combination acellular pertussis vaccines.     

Mapplet: a CORBA-based genome map viewer

BACKGROUND: Pertussis vaccination in infancy has been suggested to increase the risk for development of asthma and allergy. OBJECTIVE: To assess sensitization rates and development of atopic diseases in a prospective randomized controlled trial of pertussis vaccine. PATIENTS AND METHODS: A total of 669 children were randomized to 1 of 4 vaccine groups (2-component acellular pertussis, 5-component acellular pertussis, whole-cell pertussis vaccines, and placebo [diphtheria and tetanus toxoids]). Diphtheria and tetanus toxoids were also given to the children in the pertussis vaccine groups. The children were evaluated by means of questionnaires at age 2 months, 7 months, and 2 1/2 years; skin prick tests at age 7 months and 2 1/2 years; and blinded clinical investigation at age 2 1/2 years. The families were contacted at regular intervals to assess possible adverse effects after the vaccinations and symptoms of whooping cough. RESULTS: The cumulative incidence of atopic diseases was 30% and incidence rates were similar in the 4 groups after adjusting for family history. Exposure to environmental tobacco smoke and home dampness did not confound these results. The frequency of adverse effects did not differ appreciably between atopic and nonatopic children, with the exception that a nodule at the vaccination site was more frequent after whole-cell pertussis vaccination in the nonatopic children. Among 47 children with proven pertussis, atopic disease appeared in 19 (40%). Of these 47 children, 9 (19%) developed asthma, as compared with 58 (9%) noninfected children (P=.03). CONCLUSIONS: We found no support for a drastic increase in allergic manifestations after pertussis vaccination. There was a positive association between whooping cough and asthma by 2 1/2 years of age. There seems to be little reason to withhold pertussis vaccination from infants, irrespective of family history of allergy.     

Substance P- and calcitonin gene-related peptide-containing nerve fibers in the nasal mucosa of chronically hypoxic rats

Changes made in 1997 and 1998 in the U.S. childhood immunization schedule are discussed, with a focus on the use of poliovirus, pertussis, and combination vaccines. Oral poliovirus vaccine (OPV), the vaccine of choice for all four doses in the polio immunization series since 1962, can cause vaccine-associated paralytic poliomyelitis (VAPP). The inactivated poliovirus vaccine (IPV) has not been associated with VAPP but must be administered by injection and provides inferior intestinal immunity. With the reduced threat of poliovirus importation into the United States, the risk of VAPP, although low, has become less acceptable. The Centers for Disease Control and Prevention accordingly recommended a shift from OPV to IPV in the childhood immunization schedule for the United States, effective January 1997. A sequential OPV and IPV series is recommended, but the schedule includes an OPV-only option, which may be preferred in order to avoid the required injections, and an IPV-only option, which is recommended for immunocompromised persons and their contacts. Concern over local and systemic reactions associated with whole-cell pertussis vaccines, in addition to controversy over a possible relationship between the whole-cell vaccine and neurologic damage, has led to the development of new diphtheria and tetanus toxoids and acellular pertussis vaccine products for use in the diphtheria and tetanus toxoids and pertussis immunization series. Several combination products were licensed in 1997, and more are on the way. This will mean fewer inoculations for children. Increased use of IPV and acellular pertussis products could reduce the frequency of VAPP due to OPV and the local and systemic reactions associated with whole-cell pertussis vaccine.     

Randomised controlled trial of two-component, three-component, and five-component acellular pertussis vaccines compared with whole-cell pertussis vaccine. Ad Hoc Group for the Study of Pertussis Vaccines

BACKGROUND: Trials in Italy and Sweden showed high efficacy for three-component and five-component pertussis vaccines, and poor efficacy for a whole-cell vaccine licensed in the USA and a two-component vaccine. We compared the efficacy of three acellular vaccines with a UK whole-cell vaccine. METHODS: We enrolled 82,892 babies aged 2-3 months. Babies were vaccinated at age 3 months, 5 months, and 12 months, or age 2 months, 4 months, and 6 months. They were randomly assigned a two-component acellular diphtheria-tetanus-pertussis (DTP) vaccine (n = 20,697), a three-component acellular DTP vaccine (n = 20,728), a five-component acellular DTP vaccine (n = 20,747), or a UK whole-cell DTP vaccine (n = 20,720). We collected data for all reported cases of culture-confirmed pertussis during 3 years of follow-up. The treatment status of the two-component-vaccine group had to be made known midway through the trial for boosting because of poor efficacy. We included data for the two-component vaccine in the analysis of safety and immunogenicity, and data up its unmasking in secondary analyses of relative efficacy. Analyses were by intention to treat. FINDINGS: During follow-up from the third dose (mean 22 months), in the 3 months, 5 months, 12 months schedule, there were 15 cases of culture-confirmed pertussis with at least 21 days of paroxysmal cough in the whole-cell group, relative risk 1.00, compared with 13 in the five-component group (0.85 [95% CI 0.41-1.79]), and 21 in the three-component group (1.38 [0.71-2.69]). For culture-confirmed pertussis, with or without cough, there were 19 cases in the whole-cell group (1.00). 27 in the five-component group (1.40 [0.78-2.52]), and 49 in the three-component group (2.55 [1.50-4.33]). In the intention-to-treat analyses, from the first dose in the 3 months, 5 months, 12 months schedule the whole-cell vaccine was significantly more protective than the three-component vaccine against typical pertussis. Between the second and the third doses, culture-confirmed pertussis with any cough and with at least 21 days of paroxysmal cough was significantly more frequent in the two-component group than in the three-component group, and in the three-component group than in the five-component and the whole-cell groups, respectively. The serological response of the acellular vaccines in the 2 months, 4 months, 6 months schedule were similar to those previously reported. The whole-cell vaccine was highly immunogenic for fimbriae, pertactin, and filamentous haemagglutinin, but had a low antipertussis toxin response. Hypotonic hyporesponsiveness occurred significantly more frequently in the whole-cell group (p < 0.05) and was more frequent in the acellular groups than previously reported. High fever and seizures occurred more frequently after whole-cell vaccine than after any of the acellular vaccines (p < 0.001). INTERPRETATIONS: The efficacy of the UK whole-cell vaccine and the five-component and three-component vaccines was similar against culture-confirmed pertussis with at least 21 days of paroxysmal cough. The lower efficacy of the three-component vaccine against mild disease suggests that fimbriae have a role in protection against infection. The efficacy of acellular vaccines depends on the number of components, and different whole-cell vaccines have variable efficacies.     

What uses for the acellular pertussis vaccine?

The acellular pertussis vaccine offers a better tolerance as compared with the whole cell pertussis vaccine. It has also a good protective effect against whooping cough. However given as a combined pentavalent vaccine for the primary immunization of infants, it appears to introduce an immune interference leading to a diminished response to the Haemophilus type b or poliomyelitis valence according to the type of vaccine. Thus it is recommended that immunization against whooping cough in France in the coming years uses whole cell pertussis combined vaccine for the primary immunization of infants at 2, 3 and 4 months, the acellular pertussis vaccine being used for the booster injections at 18 months and 10-11 years.     

Safety and immunogenicity of a combined diphtheria-tetanus-acellular pertussis-inactivated polio vaccine-Haemophilus influenzae type b vaccine administered at 2-4-6-13 or 3-5-12 months of age

METHODS: In an open randomized study we compared the safety and immunogenicity of two schedules for priming and booster vaccinations of infants. A pentavalent combination vaccine, including a lyophilized Haemophilus influenzae type b-tetanus toxoid conjugate vaccine reconstituted with a liquid diphtheria, tetanus, acellular pertussis (pertussis toxoid and filamentous hemagglutinin) and inactivated polio vaccine (DTaP-IPV/Act-HIB; Pasteur Mérieux Connaught, Lyon, France) was administered to 236 Swedish infants either at 2, 4 and 6 months or at 3 and 5 months, and a booster dose was administered 7 months after the last primary dose. Adverse events were monitored by diaries for 3 days after each vaccination and by questions at the ensuing visits. Antibodies against the different vaccine components were analyzed after the primary series of vaccinations, before and after the booster injections. RESULTS: There were no serious adverse reactions, and the rates of febrile events and local reactions were low in both groups. The three dose primary schedule induced higher geometricmean concentrations for all antigens than did the two dose schedule, but there were no differences between the groups in proportions with protective antibody titers against diphtheria, tetanus, Hib and polio or in proportions with certain defined levels of pertussis antibodies. Prebooster results showed a similar pattern, with the exception that the group primed with three injections showed higher proportions of infants with detectable antibodies against polio-virus types 1 and 3. After booster vaccinations there were no differences between the two schedules in geometric mean or in proportions with antibodies above defined antibody concentrations, indicating effective priming from both primary series of vaccinations. Conclusion. The combined vaccine DTaP-IPV/ Act-HIB vaccine was equally safe and immunogenic when administered according to both time schedules studied.     

Rational approaches to reduce adverse reactions in man to vaccines containing tetanus and diphtheria toxoids

Adverse reactions to routine vaccines are obstacles to the mass vaccination campaigns. Though the absolute safety of any injectable vaccine cannot be guaranteed, the adverse side effects to vaccines can be minimized by practicing existing scientific knowledge. Adverse side effects to tetanus and diphtheria toxoids have been known for many years and there have been ways to minimize these reactions. These procedures did not get wide acceptance, because the current partially purified tetanus and diphtheria vaccines meet the regulatory requirements and the manufacturers are reluctant to change the established procedures of production due to the amount of work involved in the regulatory issues under the current Good Manufacturing Practices (GMP). Due to the recent epidemic of diphtheria in the independent states of the former Soviet Union, and its potential for spread to other European Countries, vaccination campaigns with tetanus and diphtheria vaccines received a new boost with several international agencies. In this report, we review the causes for adverse reactions to tetanus and diphtheria vaccines and offer practical suggestions for minimizing these reactions. The major issues in minimizing adverse reactions to these vaccines include: (1) purifying the toxins before detoxification as the reactogenic accessory antigens get covalently bound to the toxins during detoxification; (2) either using well-tolerated adjuvants which do not elicit the production of antigenic specific IgE antibodies responsible for adverse reactions or by using non-adjuvanted highly immunogenic polymerized antigens; (3) checking the status of immunity by recently developed rapid serological methods or by the Schick skin-test for diphtheria to avoid allergic or Arthus-type reactions. These approaches are applicable to industrial scales and would result in a pure, less reactogenic and better characterized toxoids antigens which would be more suitable for combined vaccines comprising highly purified acellular pertussis components, polysaccharide-protein conjugates and other antigens.     

Inadvertent administration of DTP and DT after age six as recorded in the Vaccine Adverse Event Reporting System

OBJECTIVE: Diphtheria and tetanus toxoids and whole-cell pertussis vaccine (DTP) and pediatric diphtheria and tetanus toxoids (DT) are not recommended for individuals > or = 7 years of age due to increased adverse reactions and the low pertussis case-fatality rate. Our objective was to determine if reactions to DTP and DT in individuals > or = 7 years of age were due to administration of pediatric DTP or DT instead of adult tetanus and diphtheria toxoids (Td), after adjusting for database inaccuracies. METHODS: We analyzed data from the Vaccine Adverse Event Reporting System (VAERS) reported from July 1, 1990 through March 31, 1992. Vaccine manufacturers were contacted to verify whether lot numbers indicated DTP or DT. RESULTS: According to VAERS's data, among individuals 7 years of age or older, 26 received DTP and 77 received DT. When lot numbers were compared with manufacturers' records, 8 of the 77 DT doses were confirmed; 11 had incorrect or missing lot numbers; one was a duplicate; 56 were Td; and one was neither DT nor Td. Alleged adverse reactions included fever, headache, and convulsions. CONCLUSION: Individuals > or = 7 years of age are inadvertently receiving DTP or DT and may be unnecessarily experiencing adverse reactions. The 1992 VAERS database offers opportunities to investigate hypotheses but should be interpreted with caution due to inaccuracies in reporting and duplicate entries.     

Ogura and Powers: "Functional restitution of traumatic stenosis of the larynx and pharynx." (Laryngoscope 1964;74: 1081-1110)

The objective of this study was to evaluate the immune response and reactogenicity of a combined hepatitis B, diphtheria, tetanus and whole-cell Bordetella pertussis (DTPw-HBV) vaccine administered to healthy infants at 2, 4 and 6 months of age. A total of 179 infants (6-12 weeks of age) received three doses of DTPw-HBV vaccine. Blood samples for antibody determinations were taken before vaccination, 2 months after the second dose and 1 month after the third dose. Solicited and unsolicited symptoms were recorded by parents in a diary card. All vaccinees had protective levels of anti-HBs [geometric mean titre (GMT): 1526 mIU.ml-1], anti-diphtheria and anti-tetanus antibodies, 1 month after the third dose. Ninety-two percent of the subjects exhibited a response to the B. pertussis component. Most (99.4%) solicited reactions occurred within the first 48 h and the majority were mild or moderate. The safety, immunogenicity of this tetravalent vaccine was demonstrated when it was administered in infants following the 0, 2, 4-month dosing schedule.     

Antibody and cell-mediated immune responses to booster immunization with a new acellular pertussis vaccine in school children

235 healthy 10-12 years old school children were randomly immunized with either a booster dose of diphtheria-tetanus-acellular pertussis (dTap) or diphtheria-tetanus (dT) vaccine. For this booster immunization designed for school children and adults, the quantities of Bordetella pertussis antigens in the dTap vaccine had been reduced to one third of those of the Infanrix vaccine (SmithKline Beecham) commonly used for infants. IgG antibodies and cell-mediated immune (CMI) responses to pertussis toxin (PT), pertactin (PRN) and filamentous hemagglutinin (FHA) were assessed by an enzyme immunosorbent assay and in vitro proliferation of peripheral blood mononuclear cells, respectively. Before immunization, 55%, 80% and 99% of children had detectable serum IgG antibodies to PT, PRN and FHA, whereas CMI response was found in 35%, 27% and 50% of children, respectively. After immunization, a 20-30-fold increase in geometric mean level (GML) of antibodies to the pertussis antigens occurred and CMI response to PT, PRN and FHA was seen in 88%, 94% and 100% of children, respectively. Adverse reactions following the immunization were rare. The results show that booster immunization with an acellular pertussis vaccine with reduced concentrations of antigens induces both antibody and CMI responses and support further studies of this pertussis vaccine in school children.     

Passive-active immunization in infants of hepatitis Be antigen-positive mothers. Comparison of the efficacy of early and delayed active immunization

OBJECTIVE: To assess the efficacy of late active immunization against hepatitis B concomitant with diphtheria, pertussis, tetanus, and polio vaccine in high-risk infants receiving hepatitis B immune globulin at birth. DESIGN: Randomized study of infants born to mothers positive for hepatitis B surface antigen (HBsAg) and hepatitis Be antigen (HBeAg). SETTING: Three large city hospitals and one rural area providing prenatal care and obstetric services. SUBJECTS: Eighty neonates of HBsAg- and HBeAg-positive carrier mothers received 0.5 mL/kg of body weight hepatitis B immune globulin within 2 hours of birth and hepatitis B vaccine (10 micrograms) at 0, 1, 2, and 11 months of age (group A) or at 3, 4, 5, and 11 months of age concomitant with diphtheria, pertussis, tetanus, and polio immunization (group B). A second dose of hepatitis B immune globulin was given to infants on schedule B at 3 months. MAIN OUTCOME MEASURES: Blood samples were collected at 0, 3, 6, 11, and 12 months of age and tested for antibodies against hepatitis B core antigen and HBsAg. Follow-up visits were scheduled annually up to 5 years of age. RESULTS: Eight infants were excluded from analysis. During the study period, six children became HBsAg carriers, three in each group, which corresponds to a 5-year incidence of infection of 9% and 8% for groups A (three of 35) and B (three of 37), respectively. Subclinical infections (persistent anti-HBc positivity beyond month 12 or appearance of anti-HBc) were encountered in another eight infants (four in each group). CONCLUSION: Late active immunization starting at 3 months of age appears to provide similar protective efficacy as active immunization starting at birth when combined with hepatitis B immune globulin at 0 and 3 months of age.     

Reversal and prevention of cerebral vasospasm by intracarotid infusions of nitric oxide donors in a primate model of subarachnoid hemorrhage

OBJECTIVE: To determine the frequency of adverse reactions, particularly the occurrence of apnea, among preterm infants after immunization with diphtheria and tetanus toxoids and whole cell pertussis vaccine adsorbed (DTP) and Haemophilus influenzae type b conjugate (HibC) vaccine in the neonatal intensive care unit. STUDY DESIGN: After the occurrence of apnea in two preterm infants following immunization with DTP and HibC, a prospective surveillance of 97 preterm infants younger than 37 weeks of gestation who were immunized with DTP (94 also received HibC at the same time) in the neonatal intensive care unit was performed to assess the frequency of adverse reactions and in particular, the occurrence of apnea. For each infant, data were recorded for a 3-day period before and after receipt of the immunization. RESULTS: The majority of preterm infants tolerated immunizations with DTP and HibC without ill effects. However, 12 (12%) infants experienced a recurrence of apnea, and 11 (11%) had at least a 50% increase in the number of apneic and bradycardic episodes in the 72 hours after immunization. This occurred primarily among smaller preterm infants who were immunized at a lower weight (p = 0.01), had experienced more severe apnea of prematurity (p = 0.01), and had chronic lung disease (p = 0.03). CONCLUSION: The temporal association observed between immunization of preterm infants and a transient increase or recurrence of apnea after vaccination merits further study. Cardiorespiratory monitoring of these infants after immunization may be advisable.     

Safety and immunogenicity of a recombinant hepatitis B vaccine administered to infants at 2, 4 and 6 months of age. The Kaiser-UCLA Vaccine Study Group

A recombinant hepatitis B vaccine was administered to over 5000 infants in a prospective, randomized and blinded study. Infants were given either recombinant hepatitis B vaccine (Engerix-B, SmithKline Beecham Pharmaceuticals, 10 micrograms dose-1) or a Haemophilus influenzae type b (Hib) conjugate vaccine at 2, 4 and 6 months of age simultaneously with diphtheria-tetanus-pertussis and oral polio vaccines. Adverse reactions were ascertained by parental reports and interviews, and review of medical records. Blood specimens collected from 269 infants given hepatitis B vaccine were assayed for antibody to hepatitis B surface antigen (anti-HBs) by enzyme immunoassay. Infants given hepatitis B vaccine experienced low rates of adverse reactions that were similar or lower than the rates in infants given Hib conjugate vaccine. The geometric mean anti-HBs concentrations were 9.6 mIU ml-1 after one dose, 333 mIU ml-1 after two doses and 1812 mIU ml-1 after three doses (99% had levels > or = 10 mIU ml-1). Antibody responses to diphtheria and tetanus toxoids were unaffected by simultaneous administration of hepatitis B or Hib conjugate vaccine. Engerix-B vaccine was safe and immunogenic when given with other routine childhood immunizations at 2, 4 and 6 months of age, and should provide long-term protection against hepatitis B virus infection.     

Influence of high titers of maternal antibody on the serologic response of infants to diphtheria vaccination at three, five and twelve months of age

Diphtheria antitoxin was determined in serum from 44 pregnant women, of whom 26 had received one injection of diphtheria toxoid during pregnancy. Their infants were vaccinated with a combined diphtheria-tetanus vaccine at 3, 5 and 12 months of age. This vaccination schedule has been used in Sweden since 1986, replacing the old schedule of vaccination at 3, 4.5 and 6 months of age originally designed for diphtheria-tetanus-pertussis vaccine, which had not been used after cessation of general vaccination against pertussis in 1979. Serum samples from the infants were obtained at 3, 7 and 18 months of age. After 2 injections infants of mothers with high antitoxin titers, > or = 0.1 IU/ml, tended to have lower antitoxin titers than infants of mothers with low antitoxin concentrations (P = 0.067). All children had, however, antitoxin above the minimum protective level of 0.01 IU/ml. Median antitoxin titers were 1.6 IU/ml in both groups after the third booster injection. Four infants of mothers who had been vaccinated during pregnancy and who had titers of > or = 0.4 IU/ml did not reach the 0.1 IU/ml level after 2 injections: all 4 responded with high antitoxin titers after the third dose. Thus all infants were primed by 2 doses of vaccine, irrespective of maternal antibody concentration. The repressive effect of maternal antibody on titers noted after 2 doses was no longer observed after the third, booster dose.     

Anterior-inferior capsular length insufficiency in the painful shoulder

BACKGROUND: Haemophilus influenzae type b (Hib) conjugate vaccines have demonstrated an impressive impact in diminishing Hib disease in industrialized countries. However, their high cost prompts nonindustrialized countries to corroborate their effectiveness under local conditions before considering their programmatic implementation. Such a postlicensure evaluation of vaccine effectiveness was undertaken in Chile. METHODS: After its licensure in Chile polyribosylribitol phosphate-tetanus toxoid protein conjugate vaccine (PRP-T), combined with diphtheria-tetanus-pertussis vaccine, was introduced into the Expanded Program on Immunization schedules in 36 health centers throughout metropolitan Santiago for 12 months, whereas 35 similar health centers administered only diphtheria-tetanus toxoid-pertussis vaccine. Bacteriologic surveillance data for invasive Hib cases collected over the ensuing 30 months were analyzed. RESULTS: In an intent-to-vaccinate (effectiveness) analysis, PRP-T provided 90.2% protection (95% confidence interval, 74.5 to 100%) against invasive Hib disease (40 vs. 4 cases, P < 0.001). Vaccine effectiveness was 91.3% against meningitis (22 vs. 2 cases) and 80% against pneumonia and empyema (10 vs. 2 cases, P = 0.039). Vaccine efficacy among infants who received all three doses of PRP-T was 91.7% (95% confidence interval, 64.8 to 100%). CONCLUSIONS: Programmatic use of Hib conjugate vaccine administered in combination with diphtheria-tetanus-pertussis vaccine constitutes a highly effective and practical intervention in Chile, a newly industrializing country.     

Reflections on the effectiveness of the new combined vaccines]

The combination vaccines are very useful to reduce the number of contacts required to immunize a child fully and to improve the vaccine coverage. Recently the new combinations between Haemophilus Influenzae vaccine (PRP-T) and pertussis vaccines in D-T-P (IVP) combined vaccines have suggested interferences with immunogenicity for PRP-T vaccines. The interference for pertussis antibodies is not significative. The depression of antiPRP antibodies is shown with the whole-cell pertussis vaccine, but the level of antibodies is related to a good protective efficacy. Inversely, when PRP-T vaccine is combined with acellular pertussis vaccines, the antibodies levels are lower, especially the number of children with a level higher than 1 mcg/ml. At the present time, these combinations between PRP-T vaccines and acellular pertussis vaccines are not recommended for primary immunization in infants in France. Such constations emphasize the necessity to perform wide comparative trials to test immunogenicity for all the next combinations between old and new vaccines. A decrease in immunogenicity of combination vaccines is acceptable as long as protective efficacy is preserved. It is possible that the growing number of new vaccines to combine will be limited to keep a clinical efficacy.     

Lumbar foraminal stenosis: critical heights of the intervertebral discs and foramina. A cryomicrotome study in cadavera

An immunization program against diphtheria has been implemented in Taiwan since 1955, using combined diphtheria, pertussis and tetanus (DPT) vaccine. Diphtheria immunoglobulin (DIG) level was assessed in serum samples obtained from 1138 children, aged 3-6 years from north, south, east and central part of Taiwan by the VERO cell neutralization method. Specimens were collected by simple random sampling of residents from Hsinchu, Taichung, Pingtung and Hwalien counties, including both aborigines and non-aborigines. The former lived in one or two villages in each county, and the latter lived in a single village next to the former. Ninety-five percent (1086/1138) had a DIG titre > or = 0.01 IU/ml. There was no significant difference by sex, or by residential area. Seventy-nine percent (901/1138) of the children had completed the primary immunization schedule (at the age of 2, 4, 6 and 18 months), and the prevalence of DIG titre > or = 0.1 IU/ml considered to be long-term protective was as follows: 74.6% for 3-year group; 74.5% for 4-year group; 67.9% for 5-year group; 84.7% for 6-year group (including 52.2% who had had a booster shot at early primary school). These findings show that the diphtheria vaccination program provides good immunity in childhood.     

Relationship between structure and neutralizing activity of rabbit tetanus antibodies elicited by acellular and whole-cell pertussis DTP vaccines

Symmetric and asymmetric IgGs having different neutralizing capacity are synthesized in variable proportions by the same clones during the course of immune response. The neutralizing activity of tetanus antibodies was studied in rabbits vaccinated with acellular (DTPa) or whole-cell pertussis (DTPw) vaccines. Symmetric and asymmetric F(ab)'2 fragments from the IgG fraction of the peak serum pools from each group of rabbits were purified by concanavalin A chromatography and measured by ELISA. After the third vaccine dose the asymmetric antibody percentage for DTPw (40%) was twice that for DTPa (20%). The neutralizing activity of asymmetric antibodies was roughly sixfold lower than symmetric ones. When antibody values titrated by ELISA approach minimal protective level, the proportion of symmetric antibodies with high toxin neutralizing activity acquires crucial importance.     

An acellular pertussis vaccine based on the natural complex of antigens isolated from the supernatant of a synthetic culture medium

A highly effective technology for obtaining a protective antigenic complex, including the main Bordetella pertussis protective antigens (pertussis toxin, filamentous hemagglutinin, agglutinogens, pertactin and adenylate cyclase) and isolated from the supernatant of B. pertussis cultivation medium, has been developed. A new method for the detoxication of antigenic complex which more available to preserve the protective property was suggested. Experimental batches of monovaccine and adsorbed DPT vaccine with the acellular pertussis component, possessing high protective activity and low histamine-sensitizing properties, have been obtained. The stability of protective properties both in liquid and lyophilized acellular pertussis preparations has been noted.     

Pertussis in Massachusetts, 1981-1991: incidence, serologic diagnosis, and vaccine effectiveness

Massachusetts provides diphtheria-tetanus toxoid-pertussis (DTP) vaccine, and since 1980 has monitored pertussis with a statewide diagnostic service. The incidence of bacteriologically confirmed pertussis was 104.5 per 100,000 person-years in 1-month-old infants and declined progressively thereafter. Infants < 6 months old experienced disproportionate morbidity: 44% of bacteriologically confirmed pertussis, 64% of hospitalizations, and 71% of hospital days. Most children with pertussis had received < 3 DTP doses during childhood, whereas 87% of adolescents with pertussis had received > or = 4 doses. Serodiagnosis by single serum anti-pertussis toxin antibody ELISA increased the incidence of confirmed pertussis in persons 11-19 years old from 3.0 to 12.9 per 100,000 and in persons > or = 20 years old from 0.16 to 0.56 per 100,000. Bacteriologic methods underestimate pertussis incidence, but a single serum anti-pertussis toxin antibody ELISA is a practical method for population-based diagnosis in adolescents and adults.