News Article -- March 29, 2007

DVC Hosts Guest Lecture on Paramyxoviruses as Vaccines and Vaccine Vectors

Photomicrographic detection of respiratory syncytial virus (RSV). Source: CDC

Today DynPort Vaccine Company hosted the second presentation in its ongoing scientific lecture series. Peter L. Collins, PhD, presented on several topics to an audience of about 50 scientists and technical personnel.

RSV Vaccine Candidates
First, Dr. Collins discussed applications for reverse genetics in live-attenuated vaccine candidates for human respiratory syncytial virus (RSV), human metapneumovirus, and human parainfluenza virus (HPIV) types 1, 2 and 3 for pediatric respiratory disease. The leading viral agent of severe pediatric respiratory diseases worldwide, HRSV is a paramyxovirus—-like a number of other important human diseases like mumps and measles—-and a major cause of bronchiolitis and pneumonia in infants and children.

Dr. Collins outlined the process for producing these vaccine candidates using reverse genetics for recovery of infectious RSV from cloned complementary DNA, and noted that a combined RSV and HPIV3 vaccine designed for intranasal administration will likely be the first viable candidate. He also discussed the need to obtain an appropriate balance between attenuation and immunogenicity, and the difficulty of achieving this goal.

Because conventional methods of attenuation, such as cold passage and chemical mutagenesis, failed to produce a satisfactorily attenuated candidate, researchers shifted their focus to a recombinant system and explored attenuation by deleting non-essential genes and identifying attenuating point mutations in previously developed candidates. He also presented data on RSV vaccine candidates in Phase 1 clinical studies, and described additional candidates to be evaluated in the next year. Dr. Collins also described the novel approach of using an attenuated version of HPIV3 to vector RSV protective antigens. Advantages of HPIV-vectored RSV vaccines include simplified development and the incorporation of two major pathogens in one vaccine, with the disadvantage that only a subset of RSV antigens can be addressed using this platform.

Paramyxoviruses as Vectors for Highly Pathogenic Viruses
In the second portion of his presentation, Dr. Collins discussed the advantages of vectored vaccines for highly pathogenic emerging viruses, like Severe Acute Respiratory Syndrome (SARS). Dr. Collins also presented research data on using HPIV3 as a vector for intranasal immunization against Ebola virus, the most deadly viral hemorrhagic fever known. Finally, he discussed using avian paramyxoviruses, such as Newcastle disease, as a vaccine vector in humans to address highly pathogenic threats like SARS and avian influenza (H5N1), and noted that research is ongoing in the area of non-human viral vectors.

About Dr. Collins
Dr. Collins is a Senior Investigator at the National Institute of Allergy & Infectious Diseases (NIAID), one of the National Institutes of Health (NIH). He received a PhD in Microbiology from the University of Connecticut in 1981, investigating gene expression by Newcastle disease, vesicular stomatitis and Sindbis viruses. He had three years of postdoctoral training at the University of North Carolina, where he initiated the molecular cloning of HRSV. Dr. Collins has been with NIAID since 1984. He has published 245 papers, reviews and book chapters, and holds 11 U.S. patents, with a similar number pending.

About the Series
The DVC Scientific Seminar Series is presented by DVC’s Science Department.

The next event in this series was held on April 19, 2007, when Dr. Anil Diwan of TheraCour Technologies discussed Nanoviricides.


Note: Links to outside resources were included in this article to provide additional information on related topics. These Web sites do not necessarily reflect the views of either Dr. Collins or DVC.