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ETHICAL AND NON-ETHICAL VACCINES FOR WEST NILE VIRUS
EMERGE
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.
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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.
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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
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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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