Clinical trials of 2009 H1N1 influenza vaccines

Sun, 13 Sep 2009 13:37:45 PST

( from http://www.rxpgnews.com ) We are encouraged by reports that are now emerging from various clinical trials of 2009 H1N1 influenza vaccines, conducted by various vaccine manufacturers. We expect additional companies to announce their preliminary trial results shortly. The early data from these trials indicate that 2009 H1N1 influenza vaccines are well tolerated and induce a strong immune response in most healthy adults when administered in a single unadjuvanted 15-microgram dose. We congratulate the companies on these trials, which are an important part of the ongoing worldwide effort to develop vaccines to protect the public from 2009 H1N1 influenza.

The National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, also is conducting clinical trials of 2009 H1N1 influenza vaccines, produced by Sanofi Pasteur and CSL Limited. The NIAID trials are testing two different dosages (15 micrograms versus 30 micrograms) and evaluating the immune response to one and two doses of these vaccines. More than 2,800 people are participating in ongoing NIAID trials of these vaccines.

We are pleased to note that preliminary analyses of early data from the NIAID trials align with the recently announced findings and those to be announced imminently by other companies in that both vaccines studied induced what is likely to be a protective immune response in most adults following a single dose in the same amount (15 micrograms) used in seasonal flu vaccines. Specifically, in blood samples obtained 8 to 10 days after vaccination

Among healthy adults who received a single 15-microgram dose of the Sanofi Pasteur vaccine, a robust immune response was measured in 96 percent of adults aged 18 to 64 and in 56 percent of adults aged 65 and older.

Similarly, among healthy adults who received a single 15-microgram dose of the CSL Limited vaccine, a robust immune response was measured in 80 percent of adults aged 18 to 64 and in 60 percent of adults aged 65 and older.

Additional data from the NIAID trials are forthcoming. However, on the basis of these strong early data, our results are consonant with other reports that a single 15-microgram dose of unadjuvanted 2009 H1N1 influenza vaccine is well tolerated and induces a robust immune response in healthy adults between the ages of 18 and 64. For adults aged 65 and older, the immune response to 2009 H1N1 influenza vaccine is somewhat less robust, as is the case with seasonal influenza vaccines.

We note that the slight discrepancies seen in our trials between the Sanofi Pasteur and CSL Limited vaccines may be due to technical differences in the preliminary measurement of the amounts of antigen in the doses used in the clinical trial lots and the relatively limited numbers of samples studied to date, as well as the fact that our data are drawn from a very early time point after immunization.

Analysis of a critical protein produced by the 2009 H1N1 influenza A virus

Sun, 24 May 2009 04:17:00 PST

( from http://www.rxpgnews.com ) In just two weeks from the time the first patient virus samples were made available, Singapore scientists report an evolutionary analysis of a critical protein produced by the 2009 H1N1 influenza A virus strain.

In the Biology Direct journal's May 20th issue, Sebastian Maurer-Stroh, Ph.D., and his team of scientists at the Bioinformatics Institute (BII), one of the research institutes at Singapore's Biopolis, also demonstrated the use of a computational 3-dimensional (3D) structural model of the protein, neuraminidase.

"Because we were working as a team, driven by the common goal to understand potential risks from this new virus, our group at BII was able to successfully complete this difficult analysis within such a short time," said Dr. Maurer-Stroh, BII principal investigator and first author of the paper.

BII's interactive 3D model is available at the following link: http://mendel.bii.a-star.edu.sg/SEQUENCES/H1N1/

With the 3D model, Dr. Maurer-Stroh and his team were able to map the regions of the protein that have mutated and determine whether drugs and vaccines that target specific areas of the protein were effective. Among their findings:

a. neuraminidase structure of the 2009 H1N1 influenza A virus has undergone extensive surface mutations compared to closely related strains such as the H5N1 avian flu virus or other H1N1 strains including the 1918 Spanish flu;
b. neuraminidase of the 2009 H1N1 influenza A virus strain is more similar to the H5N1 avian flu than to the historic 1918 H1N1 strain (Spanish flu);
c. current mutations of the virus have rendered previous flu vaccinations directed against neuraminidase less effective; and
d. commercial drugs, namely Tamiflu® and Relenza®, are still effective in treating the current H1N1 virus.

With the Biology Direct journal paper, the Singapore scientists have become the first to demonstrate how bioinformatics and computational biology can contribute towards managing the H1N1 influenza A virus.

"BII's H1N1 virus sequence study marks a significant milestone in the use of computational biology methods in understanding how the mutations of the fast evolving influenza virus affect immunogenic properties or drug response," said BII Director Frank Eisenhaber, Ph.D. "This information helps to develop a strategy for fighting the H1N1 virus and for organising an effective treatment for patients."

Other technologies to tackle the 2009 H1N1 Influenza A virus have been developed by scientists at Biopolis research institutes sponsored by Singapore's A*STAR (Agency for Science, Technology and Research). They include:

a chip that is able to quickly sequence or decode the genes in the flu virus and distinguish between the H1N1, seasonal, and mutated flu strains, at the Genome Institute of Singapore (GIS).
a microkit for the detection and identification of the flu virus strain within 2 hours, at the Institute of Bioengineering and Nanotechnology (IBN).
a molecular diagnostic assay to distinguish between the H1N1 and seasonal flu strains, at the Institute of Molecular and Cell Biology (IMCB).

RxPG News : H1N1

Clinical trials of 2009 H1N1 influenza vaccines

Analysis of a critical protein produced by the 2009 H1N1 influenza A virus