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Biomedical subjects

Thomas C Luke

Publications and source records attributed to Thomas C Luke.

3 recordsLinked to original sources

Meta-analysis: convalescent blood products for Spanish influenza pneumonia: a future H5N1 treatment?

BACKGROUND: Studies from the Spanish influenza era reported that transfusion of influenza-convalescent human blood products reduced mortality in patients with influenza complicated by pneumonia. Treatments for H5N1 influenza are unsatisfactory, and convalescent human plasma containing H5N1 antibodies could be an effective therapy during outbreaks and pandemics. PURPOSE: To determine whether transfusion with influenza-convalescent human blood products reduced the risk for death in patients with Spanish influenza pneumonia. DATA SOURCES: Manual search of English-language journals from 1918 to 1925. Citations from retrieved studies were also searched. STUDY SELECTION: Published English-language studies that had at least 10 patients in the treatment group, used convalescent blood products to treat Spanish influenza pneumonia in a hospital setting, and reported on a control or comparison group. DATA EXTRACTION: Two investigators independently extracted data on study characteristics, outcomes, adverse events, and quality. DATA SYNTHESIS: Eight relevant studies involving 1703 patients were found. Treated patients, who were often selected because of more severe illness, were compared with untreated controls with influenza pneumonia in the same hospital or ward. The overall crude case-fatality rate was 16% (54 of 336) among treated patients and 37% (452 of 1219) among controls. The range of absolute risk differences in mortality between the treatment and control groups was 8% to 26% (pooled risk difference, 21% [95% CI, 15% to 27%]). The overall crude case-fatality rate was 19% (28 of 148) among patients who received early treatment (after <4 days of pneumonia complications) and 59% (49 of 83) among patients who received late treatment (after > or =4 days of pneumonia complications). The range of absolute risk differences in mortality between the early treatment group and the late treatment group was 26% to 50% (pooled risk difference, 41% [CI, 29% to 54%]). Adverse effects included chill reactions and possible exacerbations of symptoms in a few patients. LIMITATIONS: Studies were few and had many methodologic limitations. No study was a blinded, randomized, or placebo-controlled trial. Some pertinent studies may have been missed. CONCLUSIONS: Patients with Spanish influenza pneumonia who received influenza-convalescent human blood products may have experienced a clinically important reduction in the risk for death. Convalescent human H5N1 plasma could be an effective, timely, and widely available treatment that should be studied in clinical trials.

Antibodies, Viral↗

Rationale and plans for developing a non-replicating, metabolically active, radiation-attenuated Plasmodium falciparum sporozoite vaccine.

Annually, malaria causes >300 million clinical cases and 1 million deaths, is responsible for the loss of >1% of gross domestic product (GDP) in Africa and is a serious concern for travelers. An effective vaccine could have a dramatic impact on the disease. For 20 years, scientists have tried to develop modern, recombinant 'subunit' malaria vaccines. This has been difficult. In fact, there is only one recombinant protein vaccine on the market for any disease, and no vaccines based on synthetic peptides, recombinant viruses, recombinant bacteria or DNA plasmids. Most vaccines are based on attenuated or inactivated whole pathogens or material derived directly from the infectious agent. It is in that context that our recent report summarizing the protection of humans with attenuated Plasmodium falciparum (Pf) sporozoites produced at four different sites over 25 years is important. In studies utilizing live mosquitoes as the vaccine delivery mechanism, there was complete protection against malaria in 93% of volunteers (13/14) and 94% of challenges (33/35). Sanaria's goal is to develop and commercialize a non-replicating, metabolically active Pf sporozoite vaccine. Three practical questions must be addressed before manufacturing for clinical trials: (1) can one administer the vaccine by a route that is clinically practical; (2) can one produce adequate quantities of sporozoites; and (3) can sporozoites be produced with the physical characteristics that meet the regulatory, potency and safety requirements of regulatory authorities? Once these questions have been answered, Sanaria will demonstrate that the vaccine protects >90% of human recipients against experimental challenge with Pf sporozoites, can be produced with an efficiency that makes it economically feasible, and protects >90% of African infants and children from infection, and has severe morbidity and mortality. By producing a vaccine for travelers, Sanaria will provide the infrastructure, regulatory foundation and funds necessary to speed licensure, manufacturing and deployment of the vaccine for the infants and children who need it most.

Animals↗

Protection of humans against malaria by immunization with radiation-attenuated Plasmodium falciparum sporozoites.

During 1989-1999, 11 volunteers were immunized by the bites of 1001-2927 irradiated mosquitoes harboring infectious sporozoites of Plasmodium falciparum (Pf) strain NF54 or clone 3D7/NF54. Ten volunteers were first challenged by the bites of Pf-infected mosquitoes 2-9 weeks after the last immunization, and all were protected. A volunteer challenged 10 weeks after the last immunization was not protected. Five previously protected volunteers were rechallenged 23-42 weeks after a secondary immunization, and 4 were protected. Two volunteers were protected when rechallenged with a heterologous Pf strain (7G8). In total, there was protection in 24 of 26 challenges. These results expand published findings demonstrating that immunization by exposure to thousands of mosquitoes carrying radiation-attenuated Pf sporozoites is safe and well tolerated and elicits strain-transcendent protective immunity that persists for at least 42 weeks.

Adolescent↗