[health-vn] Experimental vaccine works against Chikungunya
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Sat Jan 30 13:17:16 EST 2010
Experimental vaccine works against Chikungunya
28 Jan 2010 21:07:45 GMT
* Mosquito-borne virus is very painful but rarely fatal
* Trade, travel, climate change boosting mosquito species
* Next step is human testing, researchers say
By Maggie Fox, Health and Science Editor
WASHINGTON, Jan 28 (Reuters) - An experimental vaccine works against the newly
spreading Chikungunya virus, at least in monkeys, and the approach may also work
against other exotic viruses, U.S. government researchers reported on Thursday.
They used virus-like particles, which are mock versions of the virus that
resemble an empty shell, to vaccinate monkeys against the rarely fatal but
painful mosquito-borne infection.
"At a time when there are no commercially available vaccines ... a virus-like
particle vaccine has the potential to have a considerable impact on the spread
of this disease," Dr. Gary Nabel of the National Institute of Allergy and
Infectious Diseases and colleagues wrote in the journal Nature Medicine
They said the same approach may be useful similar mosquito-borne viruses, known
Chikungunya, first seen in the 1950s, came back in 2004 and 2005 and has since
spread to nearly 20 countries to infect millions. The U.S. Centers for Disease
Control and Prevention has a map at http://www.cdc.gov/ncidod/dvbid/chikungunya/
It is rarely fatal but it causes debilitating pain and exhaustion and can have
long-term or even permanent effects.
"Changes in trade, travel and global climate have aided the spread of mosquito
species worldwide, which may potentially cause other alphavirus outbreaks," they
"Our approach may prove useful for vaccine development against other pathogenic
alphaviruses, including Western, Eastern and Venezuelan equine encephalitis
viruses, O'nyong-nyong virus and Ross River virus."
O'nyong-nyong virus is similar to Chikungunya and is found in Uganda, while Ross
River virus affects Australia, Papua New Guinea and other Pacific islands.
People have tried to make a Chikungunya vaccine but one attempt caused similar
symptoms to infection and others did not do well in testing.
Nabel's team tried making virus-like particles, an approach that Merck and Co
<MRK.N> uses in a vaccine against the human papillomavirus that causes cervical
These particles resemble hollowed-out viruses, which the body can recognize and
attack. They cannot cause infection on their own.
Vaccinated monkeys fought off infection and the antibodies their bodies made
against Chikungunya also protected mice, Nabel's team reported.
"Because virus-like-protein-based vaccines are currently safely used in people
for protection against hepatitis B and human papillomavirus infections, they may
prove to be a practical candidate for Chikungunya vaccine efforts," the
Nabel said the next step is human testing.
Maryland-based vaccine maker Novavax <NVAX.O> has been using virus-like
particles to make vaccines against influenza and has teamed up with Cadila
Pharmaceuticals <CADI.BO> in India to make vaccines they hope will work against
influenza and perhaps dengue fever and Chikungunya. (Editing by Eric Walsh)
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