Center for Biologics Evaluation and Research

About: Center for Biologics Evaluation and Research is a facility organization based out in Silver Spring, Maryland, United States. It is known for research contribution in the topics: Virus & Vaccination. The organization has 3024 authors who have published 4648 publications receiving 228078 citations. The organization is also known as: CBER.

West Nile virus adheres to human red blood cells in whole blood.

Abstract: Background. West Nile virus (WNV) is endemic in the United States. It is transmissible by blood transfusion, and the nation's blood supply is currently screened for WNV. Documented transmission of WNV infection through red blood cell (RBC) units in which the plasma co-component had a low viral load could be explained, in at least 1 instance, by cell-association of WNV; in this case, the RBC unit was released as negative by minipool nucleic acid testing (NAT) performed on plasma but was intermittently NAT-positive when subsequently tested as an individual sample. We hypothesized that a proportion of WNV bound to blood cells and was not measured by NAT performed on plasma samples. We have investigated whether WNV binds to RBCs, leading to reduction of WNV RNA detection by NAT performed on plasma samples.Methods. Equal volumes of leukoreduced RBCs and their corresponding plasma components from 20 blood donors with NAT results that were positive for WNV were tested in 5 replicates by reverse-transcriptase polymerase chain reaction TaqMan for WNV. In addition, aliquots from 8 of the RBC units were tested by infectivity assays using Vero cells.Results. The reverse-transcriptase polymerase chain reaction TaqMan assay showed that the viral load in the RBC components exceeded that in the corresponding plasma units by 1 order of magnitude. In addition, viruses associated with the RBCs were infectious in Vero cell cultures.Conclusions. These observations reinforce the notion that extraction of viral RNA from whole blood could improve assay sensitivity for blood donor screening and further reduce the residual risk of WNV transmission through transfusion.

Infant immunization with acellular pertussis vaccines in the United States: assessment of the first two years' data from the Vaccine Adverse Event Reporting System (VAERS).

Abstract: Objective. To evaluate the safety of infant immunization with acellular pertussis vaccines in the United States. Background. The US Food and Drug Administration approved the first acellular pertussis vaccine for use in infants in the United States on July 31, 1996. Outcome Measures. Adverse events in the United States after infant immunization with pertussis-containing vaccines, representing temporal (but not necessarily causal) associations between vaccinations and adverse events. Data Source. Reports to the Vaccine Adverse Event Reporting System (VAERS), a passive national surveillance system. Design. Reports concerning infant immunization against pertussis between January 1, 1995 (when whole-cell vaccine was in exclusive use) and June 30, 1998 (when acellular vaccine was in predominant use) were analyzed, if the reports were entered into the VAERS database by November 30, 1998. Results. During the study, there were 285 reports involving death, 971 nonfatal serious reports, and 4514 less serious reports after immunization with any pertussis-containing vaccine. For 1995 there were 2071 reports; in 1996 there were 1894 reports; in 1997 there were 1314 reports, and in the first half of 1998 there were 491 reports. Diphtheria-tetanus-pertussis vaccine (DTP) was cited in 1939 reports, diphtheria–tetanus–whole-cell pertussis–Haemophilus influenzae type b vaccine (DTPH) in 2918 reports, and diphtheria-tetanus-acellular pertussis vaccine (DTaP) in 913 reports. The annual number of deaths during the study was 85 in 1995, 82 in 1996, 77 in 1997, and 41 in the first half of 1998. The annual number of reported events categorized as nonfatal serious (defined as events involving initial hospitalization, prolongation of hospitalization, life-threatening illness, or permanent disability) to VAERS for all pertussis-containing vaccines declined: 334 in 1995, 311 in 1996, 233 in 1997, and 93 in the first half of 1998. Similarly, the annual number of less serious reports to VAERS for pertussis-containing vaccines declined: 1652 in 1995, 1501 in 1996, 1004 in 1997, and 357 in the first half of 1998. A comparison of the adverse event profiles (proportional distributions) for DTaP, DTP, and DTPH, as well as an analysis of specific adverse events considered in a 1991 Institute of Medicine report on the safety of diphtheria-tetanus-pertussis vaccine, did not identify any new, clear safety concerns. Conclusions. These findings reflect the administration of millions of doses of acellular pertussis vaccine and are reassuring with regard to the safety of marketed acellular pertussis vaccines. VAERS data, although subject to the limitations of passive surveillance, support the prelicensure data with regard to the safety of the US-licensed acellular pertussis vaccines that we evaluated.

Immunity to Visceral Leishmaniasis Using Genetically Defined Live-Attenuated Parasites

Abstract: Leishmaniasis is a protozoan parasitic disease endemic to the tropical and subtropical regions of the world, with three major clinical forms, self-healing cutaneous leishmaniasis (CL), mucocutaneous leishmaniasis (MCL), and visceral leishmaniasis (VL) Drug treatments are expensive and often result in the development of drug resistance No vaccine is available against leishmaniasis Subunit Leishmania vaccine immunization in animal models has shown some efficacy but little or none in humans However, individuals who recover from natural infection are protected from reinfection and develop life-long protection, suggesting that infection may be a prerequisite for immunological memory Thus, genetically altered live-attenuated parasites with controlled infectivity could achieve such memory In this paper, we discuss development and characteristics of genetically altered, live-attenuated Leishmania donovani parasites and their possible use as vaccine candidates against VL In addition, we discuss the challenges and other considerations in the use of live-attenuated parasites