Biomedical subjects

Robert Kohberger

Publications and source records attributed to Robert Kohberger.

5 recordsLinked to original sources

PubMed2006

Safety, efficacy, and immunogenicity of 2 doses of bovine-human (UK) and rhesus-rhesus-human rotavirus reassortant tetravalent vaccines in Finnish children.

BACKGROUND: Live oral rhesus-rhesus-human rotavirus reassortant tetravalent (RRV-TV) vaccine was efficacious against rotavirus gastroenteritis but was withdrawn because of a rare association with intussusception. A corresponding tetravalent (types G1, G2, G3, and G4) reassortant vaccine based on bovine-human (UK) rotavirus reassortant tetravalent (BRV-TV) vaccine was developed concurrently. METHODS: Before the withdrawal of RRV-TV vaccine, parallel placebo-controlled trials of BRV-TV vaccine (observer blinded) versus RRV-TV vaccine (double blinded) with a 2 : 1 ratio of vaccine : placebo were conducted in Finland in a total of 510 infants. Two doses of study vaccine or placebo were administered at ages 3 and 5 months. RESULTS: The first dose of RRV-TV vaccine was followed by a significant excess rate of febrile reactions (36%), whereas the rate of fever after the administration of BRV-TV vaccine did not differ significantly from that in the placebo group. Neither vaccine induced diarrhea. A seroresponse was detected in 97% of BRV-TV vaccine recipients and 94% of RRV-TV vaccine recipients. Both vaccines were equally effective, with 68%-69% efficacy against any and 88%-100% efficacy against severe rotavirus gastroenteritis during the first epidemic season. CONCLUSIONS: BRV-TV vaccine is a promising new candidate rotavirus vaccine, with low reactogenicity and high efficacy. Two doses of BRV-TV or RRV-TV vaccine are sufficient for the induction of protection against severe rotavirus disease.

Animals↗

PubMed2005

Serum serotype-specific pneumococcal anticapsular immunoglobulin g concentrations after immunization with a 9-valent conjugate pneumococcal vaccine correlate with nasopharyngeal acquisition of pneumococcus.

BACKGROUND: Immunization with pneumococcal conjugate vaccines (PCVs) reduces nasopharyngeal colonization by Streptococcus pneumoniae. We attempted to correlate postvaccination serum serotype-specific pneumococcal anticapsular immunoglobulin (Ig) G concentrations with new acquisitions of vaccine-type (VT) serotypes and the VT-related serotype 6A. METHODS: A total of 132 day care center attendees aged 12-35 months received a 9-valent PCV (PnCRM9) and were followed for 2 years for new nasopharyngeal acquisitions of S. pneumoniae. A total of 132 control subjects received a meningococcus type C conjugate vaccine. Serum serotype-specific pneumococcal anticapsular IgG concentrations were determined at 1 month after complete immunization. RESULTS: A logistic regression model of the probability of having a new acquisition of S. pneumoniae (for serotypes 9V, 14, 19F, and 23F) as a function of the IgG concentration showed a negative coefficient, indicating that higher IgG concentrations led to a decreasing probability of having a new acquisition, and achieved statistical significance for serotypes 14 and 19F. Similarly, a new acquisition of serotype 6A was shown to be significantly inversely related to the anti-6B IgG concentration. An effect of the IgG concentration on duration of carriage was not demonstrated. CONCLUSION: The magnitude of herd protection against S. pneumoniae provided by a PCV may depend on the magnitude of IgG concentrations.

Antibodies, Bacterial↗

PubMed2003

A trial of a 9-valent pneumococcal conjugate vaccine in children with and those without HIV infection.

BACKGROUND: Acute respiratory tract infections caused by Streptococcus pneumoniae are a leading cause of morbidity and mortality in young children. We evaluated the efficacy of a 9-valent pneumococcal conjugate vaccine in a randomized, double-blind study in Soweto, South Africa. METHODS: At 6, 10, and 14 weeks of age, 19,922 children received the 9-valent pneumococcal polysaccharide vaccine conjugated to a noncatalytic cross-reacting mutant of diphtheria toxin (CRM197), and 19,914 received placebo. All children received Haemophilus influenzae type b conjugate vaccine. Efficacy and safety were analyzed according to the intention-to-treat principle. RESULTS: Among children without human immunodeficiency virus (HIV) infection, the vaccine reduced the incidence of a first episode of invasive pneumococcal disease due to serotypes included in the vaccine by 83 percent (95 percent confidence interval, 39 to 97; 17 cases among controls and 3 among vaccine recipients). Among HIV-infected children, the efficacy was 65 percent (95 percent confidence interval, 24 to 86; 26 and 9 cases, respectively). Among children without HIV infection, the vaccine reduced the incidence of first episodes of radiologically confirmed alveolar consolidation by 20 percent (95 percent confidence interval, 2 to 35; 212 cases in the control group and 169 in the vaccinated group) in the intention-to-treat analysis and by 25 percent (95 percent confidence interval, 4 to 41; 158 and 119 cases, respectively) in the per-protocol analysis (i.e., among fully vaccinated children). The incidence of invasive pneumococcal disease caused by penicillin-resistant strains was reduced by 67 percent (95 percent confidence interval, 19 to 88; 21 cases in the control group and 7 in the vaccinated group), and that caused by strains resistant to trimethoprim-sulfamethoxazole was reduced by 56 percent (95 percent confidence interval, 16 to 78; 32 and 14 cases, respectively). CONCLUSIONS: Vaccination with a 9-valent pneumococcal conjugate vaccine reduced the incidence of radiologically confirmed pneumonia. The vaccine also reduced the incidence of vaccine-serotype and antibiotic-resistant invasive pneumococcal disease among children with and those without HIV infection.

Bacterial Capsules↗

PubMed2003

Efficacy and safety of seven-valent conjugate pneumococcal vaccine in American Indian children: group randomised trial.

BACKGROUND: Streptococcus pneumoniae is the main cause of invasive bacterial disease in children aged younger than 2 years. Navajo and White Mountain Apache children have some of the highest rates of invasive pneumococcal disease documented in the world. We aimed to assess the safety and efficacy of a seven-valent polysaccharide protein conjugate pneumococcal vaccine (PnCRM7) against such disease. METHODS: In a group-randomised study, we gave this vaccine to children younger than 2 years from the Navajo and White Mountain Apache Indian reservations; meningococcal type C conjugate vaccine (MnCC) served as the control vaccine. Vaccine schedules were determined by age at enrollment. We recorded episodes of invasive pneumococcal disease and serotyped isolates. Analyses were by intention to treat and per protocol. FINDINGS: 8292 children enrolled in the trial. In the per protocol analysis of the primary efficacy group (children enrolled by 7 months of age) there were eight cases of vaccine serotype disease in the controls and two in the PnCRM7 group; in the intention-to-treat analysis we noted 11 cases of vaccine serotype disease in the MnCC control group and two in the PnCRM7 group. After group randomisation had been controlled for, the per protocol primary efficacy of PnCRM7 was 76.8% (95% CI -9.4% to 95.1%) and the intention-to-treat total primary efficacy was 82.6% (21.4% to 96.1%). INTERPRETATION: PnCRM7 vaccine prevents vaccine serotype invasive pneumococcal disease even in a high risk population. Other regions with similar disease burden should consider including this vaccine in the routine childhood vaccine schedule.

Arizona↗

PubMed2003

Serological criteria for evaluation and licensure of new pneumococcal conjugate vaccine formulations for use in infants.

The World Health Organization (WHO) is undertaking a series of consultations on serological criteria for the evaluation and licensure of new formulations/combinations or different vaccination schedules of pneumococcal conjugate vaccines. The lack of a definitive serological correlate of protection and the multiplicity of antigens involved, especially since the clinical efficacy of most of the individual serotypes represented in the only licensed vaccine has not been established, are hindering the formulation of criteria for licensure of new formulations or combinations of the vaccine. This report analyses the various options with their relative merits and drawbacks and provides preliminary recommendations as guidance to regulatory agencies in evaluating these vaccines for the purposes of licensure. More detailed recommendations for production and control of pneumococcal conjugate vaccines, including criteria for evaluation for licensure, are currently being drafted.

Antibodies, Bacterial↗