Vaccination of COPD patients with a pneumococcus type 6B tetanus toxoid conjugate vaccine.

This paper examines how pneumococcal type 6B polysaccharide conjugated to tetanus toxoid (Pn6B-TT) compares to a 23 valent pneumococcal vaccine (pneumococcal polysaccharide (PPS)-23) with respect to immunogenicity and serum opsonic activity in patients with chronic obstructive pulmonary disease (COPD). Patients with COPD aged 55-75 yrs were vaccinated with Pn6B-TT (n=10) or with PPS-23 (n=9). Healthy young adults (HA) were vaccinated with Pn6B-TT as controls. Total antibodies to serotype 6B polysaccharide were measured by radioimmunoassay and immunoglobulin (Ig)G antibodies by enzyme-linked immunosorbent assay. Opsonic activity was measured by a phagocytosis assay using human neutrophils as effector cells. The patient groups were comparable by age, smoking history, lung function and use of steroids. COPD patients vaccinated with Pn6B-TT or PPS-23 showed an increase in IgG antibodies and a nonsignificant increase in opsonic activity. This was similar to the increase in IgG and opsonic activity seen in HA. There was a significant correlation between antibody levels and opsonic activity in COPD patients vaccinated both with Pn6B-TT and PPS-23. Pneumococcal antibodies have been shown to confer protection from infection. The results of the present study indicate that protective immunity can be expected in elderly chronic obstructive pulmonary disease patients vaccinated with conjugate vaccines.

Clostridium difficile recombinant toxin A repeating units as a carrier protein for conjugate vaccines: studies of pneumococcal type 14, Escherichia coli K1, and Shigella flexneri type 2a polysaccharides in mice.

Unlike the native protein, a nontoxic peptide (repeating unit of the native toxin designated rARU) from Clostridium difficile toxin A (CDTA) afforded an antigen that could be bound covalently to the surface polysaccharides of pneumococcus type 14, Shigella flexneri type 2a, and Escherichia coli K1. The yields of these polysaccharide-protein conjugates were significantly increased by prior treatment of rARU with succinic anhydride. Conjugates, prepared with rARU or succinylated (rARUsucc), were administered to mice by a clinically relevant dosage and immunization scheme. All conjugates elicited high levels of serum immunoglobulin G both to the polysaccharides and to CDTA. Conjugate-induced anti-CDTA had neutralizing activity in vitro and protected mice challenged with CDTA, similar to the rARU alone. Conjugates prepared with succinylated rARU, therefore, have potential for serving both as effective carrier proteins for polysaccharides and for preventing enteric disease caused by C. difficile.

Isotypes and opsonophagocytosis of pneumococcus type 6B antibodies elicited in infants and adults by an experimental pneumococcus type 6B-tetanus toxoid vaccine.

Streptococcus pneumoniae is a major respiratory pathogen of infants, children, and the elderly. Polysaccharide vaccines have been useful in adult populations but do not elicit protective immunity in infants and young children. To enhance their immunogenicity, vaccines of pneumococcal polysaccharides conjugated to proteins are being developed. In this study antibody levels and opsonic activities were compared in sera of infants and adults injected with pneumococcal polysaccharide type 6B (Pn6B) conjugated to tetanus toxoid (TT) (Pn6B-TT). Healthy infants were injected with Pn6B-TT; group A was injected at 3, 4, and 6 months of age, and group B was injected at 7 and 9 months of age. A booster injection was given at 18 months. Adults were injected once. Antibodies were measured by enzyme-linked immunosorbent assay and radioimmunoassay, and their functional activities were measured by opsonophagocytosis of radiolabelled pneumococci. In adults, increases in immunoglobulin M (IgM), IgG, IgA, IgG1, and IgG2 to Pn6B were observed. Infants reached adult levels of IgG1 anti-Pn6B after the primary injections. After the booster injection the infant groups had total IgG- and IgM-Pn6B antibody levels similar to those of adults. After the booster injection, IgG1 was the dominant infant anti-Pn6B isotype and at a level higher than in vaccinated adults, but IgA and IgG2 antibodies remained at very low levels. Opsonic activity increased significantly after Pn6B-TT injections; the highest infant sera showed opsonic activity comparable to that of vaccinated adults. Overall, opsonic activity correlated best with total and IgG anti-Pn6B antibodies (r = 0.741, r = 0.653, respectively; n = 35) and was highest in sera with high levels of all Pn6B antibody isotypes. The results indicate the protective potential of a pneumococcal 6B polysaccharide protein conjugate vaccine for young infants.

Response to pneumococcal immunization in children with and without recurrent infections.

Many children with recurrent sinopulmonary infections fail to mount an adequate humoral response following immunization with polysaccharide antigens. At present there are no controlled studies comparing responses to pneumococcal immunization in children with recurrent infections and a healthy, age-matched cohort. Immunological evaluation was performed on 66 children with recurrent sinopulmonary infections, aged 2-5 years (mean 3.06 +/- 0.92). A control group included 28 healthy, age-matched controls (mean 3.14 +/- 0.88 years). Both groups were immunized with 23 valent pneumococcal vaccine, and titers were measured before and 4 weeks after immunization. Antibody levels to 12 pneumococcal serotypes were measured via radioimmunoassay. Geometric preimmunization mean titers in the control group were 215.5 +/- 157 ngAbN/ml rising to 989.5 +/- 745 ngAbN/ml compared to 77.71 +/- 38.4 ngAbN/ml increasing to 446.7 +/- 406 ngAbN/ml in the study group (p < .05). Serotypes 3, 4, 7F, 8, 9N, and 18C were the most immunogenic, while serotypes 6A and 14 were the least. Overall, the control group responded to 7.71 +/- 1.24 serotypes versus 5.1 +/- 2.0 in the study group (p < .05), where postimmunization titers at least doubled and rose to > or = 300 ngAbN/ml. All controls responded to at least five or more serotypes, 26/28 responded to 6 or more. In contrast, only 38/66 (57%) of study patients responded to five or more serotypes, and only 27/66 (41%) responded to at least 6 of 12. Preimmunization titers of greater than 300 ngAbN/ml were present in 30% (102/336) of the control serotypes; however, only 53 of these (52%) doubled post immunization; 22% of the elevated titers decreased post immunization. Markedly elevated titers > or = 500 ngAbN/ml were present in 20% (69/336) of the preimmunization serotypes, only 39% of these doubled post immunization. Twenty-three valent pneumococcal vaccine is immunogenic in young, healthy children. A significant percentage of children with recurrent sinopulmonary infections fail to produce adequate serotype specific antibodies following pneumococcal immunization.

Immune responses of infants vaccinated with serotype 6B pneumococcal polysaccharide conjugated with tetanus toxoid.

BACKGROUND: Streptococcus pneumoniae is a major cause of meningitis, bacteremia, pneumonia and otitis media. Pneumococcal polysaccharides are not immunogenic in infants, but improved immunogenicity of polysaccharide-protein conjugates has been demonstrated. Antibiotic-resistant pneumococci have increased the need for an effective vaccine. OBJECTIVE: To study the safety and immunogenicity of a pneumococcal type 6B polysaccharidetetanus toxoid conjugate (Pn6B-TT) in infants and to assess the function of antibodies. METHODS: Healthy infants were injected, Group A at 3, 4 and 6 months (n = 21) and Group B at 7 and 9 months (n = 19). Booster injection was given at 18 months. Antibodies were measured by enzyme-linked immunosorbent assay and radioimmunoassay, and functional activity was measured by opsonization of radiolabeled pneumococci. Nasopharyngeal cultures were obtained. RESULTS: No significant adverse reactions were observed. Pn6B-IgG (enzyme-linked immunosorbent assay) increased to a geometric mean of 0.62 microgram/ml (P = 0.367, compared with prevaccination titers) in Group A at 7 months and 1.22 micrograms/ml (P < 0.001) in Group B at 10 months. Total Pn6B antibodies (radioimmunoassay) were 44 ng of antibody N/ml (P < 0.053) in Group A and 211 ng of antibody N/ml (P < 0.001) in Group B. A smaller increase in IgM and IgA anti-Pn6B was observed. Reinjection at 18 months elicited booster responses in total and IgG anti-Pn6B; 62% of those in Group A and 79% of those in Group B had > 300 ng of antibody N/ml. Opsonic activity, after initial and booster vaccinations, correlated with Pn6B-antibody titers. Three infants with nasopharyngeal cultures repeatedly positive for serogroup 6 had poor serum IgG responses. CONCLUSION: Our results demonstrate that Pn6B-TT is safe, elicits functional antibodies and memory responses in infants.

Impaired antibody responses to pneumococcal polysaccharide in elderly patients with low serum vitamin B12 levels.

OBJECTIVE: To determine whether immunocompetent elderly patients with low serum vitamin B12 levels have impaired serum antibody responses to the 23-polyvalent pneumococcal polysaccharide vaccine. DESIGN: Controlled, prospective cohort study. MEASUREMENTS: 15 patients with low serum vitamin B12 levels and 15 age- and diagnosis-matched patients with normal levels were vaccinated. Serum antibody titers to 12 pneumococcal serotypes were measured by radioimmunoassay before and 4 weeks after vaccination. RESULTS: The difference between the geometric mean of the vaccine antibody titers before and after vaccination for all 12 serotypes was lower (P = 0.005) in the patients with low vitamin B12 levels than in the patients with normal levels. When mean corpuscular volume and age were controlled for, vitamin B12 remained an independent predictor of antibody response (P = 0.005). Erythrocyte mean corpuscular volume was also an independent predictor of the increase in titer (P = 0.03). CONCLUSIONS: Patients with low vitamin B12 levels had impaired antibody responses to pneumococcal vaccine. Further study is necessary to determine whether treatment with vitamin B12 can enhance specific immunoglobulin synthesis and improve the clinical efficacy of the pneumococcal vaccine in patients with low vitamin B12 levels.

Anti-pneumococcal antibody levels three to seven years after first booster immunization in children with sickle cell disease, and after a second booster.

We measured pneumococcal antibody levels in 55 patients (ages 7 to 20 years) with sickle cell disease 3 to 7 years after the first booster immunization. Only 6 of the children had protective levels of antibodies (> 300 ng/ml) against all 12 serotypes tested. Thirty-two children (58%) had suboptimal levels against 1 to 3 serotypes; 17 had suboptimal levels against 4 to 10 serotypes. Ten patients from the latter group (ages 13 to 17 years) received a second booster 6 to 8 years after the first booster immunization, and had a marked increase in antibody levels against all serotypes with the exception of serotypes 3 and 4 in two patients and serotype 6A in one patient.

Immunodeficiency in long-term survivors of acute lymphoblastic leukemia treated with Berlin-Frankfurt-Münster therapy.

OBJECTIVE: To determine whether the immune systems of long-term survivors of acute lymphoblastic leukemia (ALL) have persistent immune defects after Berlin-Frankfurt-Münster (BFM) treatment. STUDY DESIGN: We evaluated the cellular and humoral immune responses of 13 children with ALL in complete remission and off modified protocol treatment for 2 or more years. All patients had received complete immunizations for measles, mumps, rubella, and poliovirus before ALL developed. They were challenged with Haemophilus influenzae type B (Hib) and Pneumococcus vaccines after baseline serum samples were obtained. We also determined in vivo humoral immune responses to bacteria and viruses that cause common pediatric diseases. RESULTS: Compared with age-matched control subjects, the long-term survivors of ALL had a significant difference in the presence of protective antibodies to measles (p < 0.0001) and polioviruses (p < 0.0001) in their baseline sera; more than half had no protective antibodies to one or more previously administered vaccines or related infections. Most produced protective concentrations of specific antibody after reimmunization, but some were repeatedly unable to make protective antibodies, or mount a normal antibody response, despite natural disease and/or revaccination. Four children had significant infections. CONCLUSIONS: Long-term survivors of ALL who had BFM treatment may have persistent immune defects with respect to common childhood bacterial and viral diseases they previously had, or vaccines they received.

Appropriate response to pneumococcal vaccine in celiac sprue.

Hyposplenism as a complication of celiac sprue confers an increased risk of pneumococcal sepsis, but such patients do not routinely receive pneumococcal vaccine despite reports of overwhelming pneumococcal sepsis. Because antibody response in these patients has not been previously assessed, we measured pre- and postvaccination levels in 10 patients with documented sprue. All demonstrated appropriate acute antibody responses to a polyvalent pneumococcal vaccine. Vaccination of all patients with celiac sprue seems appropriate.

Immunological function in post-traumatic splenosis.

A 28-year-old male medical student underwent splenectomy at 8 years of age due to traumatic rupture of the spleen sustained in a motor vehicle accident. Eighteen years later the patient had major abdominal surgery performed for an unrelated condition and, at the time of surgery, over 100 splenic nodules were found embedded throughout the patient's omentum, small bowel, and mesentery. An extensive study of immunological functions was carried out during the following 2 years. Through the course of this investigation, it was determined that the patient's peripheral blood smear lacked Howell-Jolly bodies and deformed or damaged erythrocytes, indicating that the splenotic tissue had the capacity to remove intranuclear inclusions from circulating red cells and to phagocytose old erythrocytes. The patient's levels of complement, serum immunoglobulins and the numbers of circulating T and B lymphocytes, helper T cells, and cytotoxic/suppressor T cells all were within the normal range. The response to Streptococcus pneumoniae polysaccharides was also normal, with increased levels of specific antibodies to all serotypes included in the vaccine 4 months after immunization. Finally, histological examination of his biopsied splenotic nodules revealed tissue that was indistinguishable from normal spleen.

HLA, Gm, and Km polymorphisms and immunity to infectious diseases in South Amerinds.

Isolated South Amerinds, a population at very high risk from infectious disease, mount good immune responses to pneumococcal polysaccharides, viral antigens and other immunogens. No unusual immunoglobulin allotype or HLA antigen, which might explain the high risk from infectious disease, was found among them. Responses are examined in relation to the immunogenetic markers that are most prevalent. Amerinds with Gm 1,2,17,21 responded less well than persons without this haplotype to 10 of 12 pneumococcal polysaccharides, and those who were homozygous at the HLA class I loci responded less well to viral antigens. However, these differences are not strong and there are few such findings relative to the number of possibilities examined. The most distinctive immunogenetic characteristic of these populations is their low level of polymorphism at all tested loci. Their susceptibility to infectious agents can be attributed to this genetic uniformity and a consequent ability of pathogens to adapt to the population.

Immunogenicity of pneumococcal revaccination in patients with chronic disease.

BACKGROUND: To prevent serious pneumococcal infections, 23-valent pneumococcal polysaccharide vaccine is recommended for individuals over 24 months of age with chronic predisposing diseases and for healthy older adults. This nonrandomized controlled study in rural Alaska assessed the immunogenicity of revaccination in adults. METHODS: Twenty-six adults, 33 to 88 years of age, vaccinated a mean of 7.4 years before this study, were matched to 26 previously unvaccinated subjects by age, number of chronic diseases, sex, and ethnicity. One or more chronic diseases were validated in 62% of subjects (32 of 52). All received a first or second intramuscular dose of pneumococcal vaccine. Antibody levels were determined by radioimmunoassay for 12 pneumococcal capsular serotypes immediately before and 20 to 84 days after vaccination. RESULTS: Six to 9 years after primary vaccination, over one third of serotype-specific antibody levels were below 500 ng of antibody nitrogen per milliliter, equal to the percentage in unvaccinated subjects of similar age. Antibody levels against all pneumococcal serotypes rose to similar levels after primary vaccination and revaccination, and 54% and 55%, respectively, of subjects who received primary vaccination and revaccination had at least a 1.4-fold increase in antibody levels. Only the antibody level for serotype 4 remained low. Neither gender nor age affected peak response. For those with chronic diseases, there was a trend toward fewer low antibody levels against three or more serotypes after revaccination (two subjects [13%]) than after primary vaccination (five subjects [31%]). CONCLUSIONS: Following the initial immunization of high-risk and elderly patients with pneumococcal polysaccharide, pneumococcal antibody levels appear to wane with time. Primary vaccination and revaccination 6 or more years after a first dose of pneumococcal vaccine stimulate comparable mean antibody levels.

Immunogenicity of the 23-valent pneumococcal polysaccharide vaccine in Alaska Native chronic alcoholics compared with nonalcoholic Native and non-Native controls.

PURPOSE: This study was designed to evaluate the immunogenicity of the 23-valent pneumococcal polysaccharide vaccine in Alaska Native chronic alcoholics and compare these responses with those in age- and sex-matched nonalcoholic, Native and non-Native control subjects. PATIENTS AND METHODS: Native alcoholic patients were recruited from the inpatient medical service and outpatient clinics. Healthy age- and sex-matched Alaska Native and non-Native nonalcoholics were recruited from hospital employees. At the initial visit, a standardized questionnaire, the Alcohol Dependency Scale, was administered to all participants. Participants were examined for liver diseases; blood was drawn for liver function tests and prevaccination pneumococcal antibody levels. Charts of all Native participants were reviewed for alcohol-related diseases. Participants received one dose of the 23-valent pneumococcal vaccine at the time of the initial visit and returned 20 to 55 days after immunization for liver function tests and pneumococcal antibody level measurement. Serotype-specific pneumococcal antibody levels were measured by radioimmunoassay. Logistic regression analysis was used to examine the proportion of persons whose serotype-specific antibody level doubled following vaccination. A model including adjustments for age, sex, and initial antibody level was used to examine the effect of alcohol status and ethnicity on response to the vaccine. Eighty-five persons completed the study. Of these, 41 were chronic alcoholics and 44 were nonalcoholic. Of these, 21 were Alaska Natives and 23 were non-Natives. RESULTS: Before vaccination, the geometric mean titers (GMTs) were similar in all 3 groups but were slightly higher in Native alcoholic participants for 11 of 12 serotypes tested. For 11 or more serotypes tested, 46% of alcoholics and 27% of nonalcoholics had total antibody levels at or above 500 nanograms of antibody nitrogen per milliliter (p = 0.11). After vaccination, the GMTs were higher in nonalcoholic than in alcoholic participants for serotypes 3, 7F, and 19F (p < 0.05). When Natives and non-Natives were compared, non-Natives had higher antibody levels than Native participants for 10 of 12 serotypes. After vaccination, 83% of alcoholics and 91% of nonalcoholics had pneumococcal antibody levels of more than 500 nanograms of antibody nitrogen per milliliter for at least 11 serotypes. When responses consisting of a twofold or greater increase in antibody level were compared, a greater proportion of nonalcoholics than alcoholics responded to serotypes 3, 4, 7F, 8, and 19F. This difference was significant for types 3 and 19F only (p < 0.05). In alcoholics there was a direct correlation between pneumococcal antibody level and age both before and after vaccination. This was significant before vaccination for serotypes 4, 6B, 18C, and 23F, and after vaccination for these types and for types 1 and 19F. In nonalcoholics there was a correlation between age and antibody response, following vaccination, for serotype 9N and 18C. Alcoholic males had antibody levels higher than that in females for most serotypes, but significantly so only for serotype 12F before vaccination, and for type 14 after vaccination. There were no sex differences seen among nonalcoholics, and no differences in response to vaccine could be detected in patients with or without liver dysfunction. CONCLUSION: In this study of Alaska Natives with chronic alcoholism, Native and non-Native participants responded adequately to immunization with the 23-valent pneumococcal vaccine, although significant differences in some serotypes were evident.

Effect of various doses of intravenous polyclonal IgG on in vivo levels of 12 pneumococcal antibodies in patients with chronic lymphocytic leukaemia and multiple myeloma.

Polyclonal intravenous IgG (IVIG) was administered as an infusion 6 times every 3 weeks (week 0, 3, 6, 9, 12, 15) in doses of 0.1, 0.4 and 0.8 g/kg BW to determine the dose causing an increase in 12 pneumococcal antibody types above the protective level of 200 ng/ml of antibody N. The dose of 0.4 g/kg BW was found to be optimal in patients with chronic lymphocytic leukaemia (CLL). From the first infusion onwards at least 80% of CLL patients had increases in all 12 antibodies. Five weeks after the last infusion the antibody levels were still elevated in 80% of patients with CLL. The dose of 0.8 g/kg raised all 12 antibodies in 53-73% of CLL patients when assessments were made after each infusion. In multiple myeloma (MM) patients, 73-82% and 73-91% of patients had increased antibody levels, respectively, before and after the 4th-6th infusions at the 0.8 g/kg dose level. However, in only 45-50% of patients did the antibodies remain increased 2 weeks after the treatment at this dose. The dose of 0.4 g/kg caused antibody increases in only 30-50% of patients when measured before the 4th-6th infusion. Serum IgG increased significantly only in the CLL patients, whereas in the MM patients it was high from the beginning owing to the disease. Therefore, the pneumococcal antibody levels were a better marker for the purpose of dose finding. The dosage recommendation in CLL is 0.4 g/kg every 3 weeks until week 12, when steady state is reached. The maintenance dose is 0.4 g/kg every 5 weeks. In MM patients, who have a faster elimination rate of antibodies, the recommended loading dose is 0.8 g/kg, followed by 0.4 g/kg every week as a continuous treatment. Treatment with IVIG in CLL and MM was generally well tolerated. Only 25% of patients experienced minor side-effects, the most frequent being febrile reactions, shivering and headache.

Synthesis of a conjugate vaccine composed of pneumococcus type 14 capsular polysaccharide bound to pertussis toxin.

Type 14 is one of the common types isolated from patients of all ages with infections caused by Streptococcus pneumoniae. Its capsular polysaccharide (Pn14) is composed of a neutrally charged tetrasaccharide repeat unit. Pn14 does not elicit protective levels of antibodies in infants and children and is a less than optimal immunogen of the 23-valent vaccine for adults. Pertussis toxin (PT) is both a virulence factor and protective antigen of Bordetella pertussis: it is not soluble at neutral pH and forms insoluble complexes with acidic polysaccharides. Both Pn14 and PT are potential components of vaccines for infants and children. Accordingly, a synthetic scheme was devised to prepare a conjugate of Pn14 and PT. An adipic acid hydrazide derivative of Pn14 was bound to PT at pH 3.9 by carbodiimide-mediated condensation. The conjugation procedure inactivated the PT as assayed by CHO cell and histamine-sensitizing activity. The Pn14-PT conjugate elicited antibodies in mice to Pn14 at levels estimated to be protective in humans and elicited neutralizing antibodies to PT. We plan to evaluate Pn14-PT clinically.

Zidovudine improves response to pneumococcal vaccine among persons with AIDS and AIDS-related complex.

Antibody responses to 23-valent pneumococcal vaccine were studied in 38 individuals infected with human immunodeficiency virus (HIV), including 6 with asymptomatic infection, 24 with AIDS or AIDS-related complex (ARC) receiving treatment with zidovudine, and 8 untreated AIDS/ARC patients. Antibody responses were significantly higher for asymptomatic persons (aggregate geometric mean, 972 ng of antibody nitrogen (AbN)/ml; P less than .001) and AIDS/ARC patients receiving a median of 12 weeks (range, 4-54) of zidovudine therapy (mean, 369 ng of AbN/ml; P less than .001) when compared with untreated AIDS/ARC patients. Antibody responses among zidovudine-treated AIDS/ARC patients were independent of the dose (mean, 629.2 mg/day; range, 100-1200 mg) or duration of zidovudine therapy. For zidovudine-treated AIDS/ARC patients, persistence of an aggregate antibody response 8 months after vaccination was associated with survival at 14 months after vaccination, whereas waning of response was not. Pneumococcal vaccine should be administered as early as possible in the course of HIV infection. Immunization should be delayed for at least 4 weeks for AIDS/ARC patients initiating zidovudine therapy.

Evaluation of monophosphoryl lipid A (MPL) as an adjuvant. Enhancement of the serum antibody response in mice to polysaccharide-protein conjugates by concurrent injection with MPL.

Concurrent injection of monophosphoryl lipid A (MPL) in saline or as an oil-in-water emulsion enhanced both the primary and secondary serum antibody responses to the capsular polysaccharide (CP) components of seven conjugates: the enhanced responses were Ag-specific. In contrast, MPL did not enhance the serum antibody response to five of the six unconjugated CP. MPL and trehalose dimycolate injected concurrently with the unconjugated Vi CP of Salmonella typhi (Vi) enhanced the serum antibody response to that Ag. MPL further enhanced the Vi antibody levels when injected with conjugates of this CP. The serum antibody responses to Pseudomonas aeruginosa exotoxin A, used as the carrier protein for the Staphylococcus aureus types 5 and 8 conjugates, were also enhanced by MPL. MPL in oil-in-water emulsion was generally more effective than when administered in saline.