Ethical and Non-Ethical Vaccines for West Nile Virus Emerge

by | Oct 15, 2007 | Archive, News | 0 comments

The following two articles appeared in Science Direct website http://www.sciencedirect.com

The first article describes using aborted fetal cell line PER C6 to produce a vaccine against West Nile Virus.  The second describes the use of Methylene Blue
as a means of providing immunity to West Nile Virus.  The difference?  Methylene Blue does not use aborted fetal cell lines and has already been approved
for human use as a safe and efficacious method of protecting against the disease, much the same as Immune Globulin is used in place of other vaccines.

Itzchak Samina, Menzo Havenga, Wouter Koudstaal, Yevgeny Khinich, Martin Koldijk, Mertyn Malkinson, Michael Simanov, Shmuel Perl, Linda Gijsbers, Gerrit Jan Weverling, Fons Uytdehaag and Jaap Goudsmit 
aKimron Veterinary Institute, PO Box 12, Bet Dagan 50250, Israel
bCrucell Holland BV, PO Box 2048, 2333CN Leiden, The Netherlands
Received 2 July 2007;  revised 4 September 2007;  accepted 15 September 2007.
Available online 15 October 2007.

Abstract

Studies were performed with an inactivated vaccine against the mosquito-borne flavivirus, West Nile virus (WNV). The mammalian cell line, PER.C6®, was selected as the platform for WNV growth since both the neurovirulent strains NY99 and ISR98 that cause epidemics in humans and high mortality in geese, respectively, could be propagated to high titers (109 to 1010 TCID50/ml) on these cells. Based on the high DNA homology of the WNV envelope (E) protein and non-structural protein 5 (NS5), and identical neurovirulence in mice and geese, we concluded that NY99 and ISR98 viruses are closely related and therefore vaccine studies were performed with ISR98 as a model for NY99. A robust challenge model in domestic geese was set up resulting in 100% mortality within 7 days of intracranial challenge with 500 TCID50 WNV. Geese were used to assess the efficacy and safety of an inactivated WNV vaccine produced on PER.C6® cells. Efficacy studies demonstrated 91.4% (53/58) protection of geese compared to no protection (0/13) in geese receiving a sham vaccine. A follow-up study in 1800 geese showed that the vaccine was safe with a survival rate of 96.6% (95% lower CL 95.7%). Initial studies on the correlates of protection induced by the vaccine indicate an important role for antibodies since geese were protected when injected intra-cranial with a mixture of serum from vaccinated, non-challenged geese and WNV. In all, these results provide a scientific basis for the development of an inactivated WNV vaccine based on NY99 produced on PER.C6® cells for human and equine use.

 

Article 2

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6T2H-4GV2PBP-3&_user=10&_coverDate=11%2F30%2F2005&_rdoc=1&_fmt=summary&_orig=article&_cdi=4919&_sort=v&_docanchor=&view=c&_ct=1025&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=92762980e5e994696aeff99c838ea5ac

Methylene blue photoinactivation abolishes West Nile virus infectivity in vivo

James F. Papin, Robert A. Floyd and Dirk P. Dittmer Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, USA
The Oklahoma Medical Research Foundation, USA
Department of Microbiology and Immunology and Lineberger Comprehensive Cancer Center,
University of North Carolina at Chapel Hill, CB# 7290, 804 Mary Ellen Jones Bldg, Chapel Hill, NC 27599-7290, USA
Received 1 March 2005;  accepted 12 July 2005.  Available online 9 August 2005.

Abstract

The prevalence of West Nile virus (WNV) infections and associated morbidity has accelerated in recent years. Of particular concern is the recent demonstration that this virus can be transmitted by blood products and can cause severe illness and mortality in transfusion recipients. We have evaluated methylene blue (MB) + light as a safe and cost-effective means to inactivate WNV in vitro. This regimen inactivated WNV with an IC50 of 0.10 μM. Up to 107 pfu/ml of WNV could be inactivated by MB + light with no residual infectivity. MB + light inactivated three primary WNV isolates from the years 1999, 2002 and 2003 and prevented mortality in a murine model for WNV infection. Since MB is already approved for human use at a dose of 100 mg/kg/day, we conjecture that MB + light treatment of blood products for high-risk patients will be efficacious and suitable for use in resource-limited settings.

 

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