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HIV/AIDS vaccine still some years away
By Zhang Feng (China Daily)
Updated: 2005-12-05 05:30
An HIV vaccine may still be a dream but scientists say that in four to five
years they may be able to tell the world which candidate vaccines could
successfully be developed into effective ones.
Currently nobody can tell exactly when an effective vaccine will be available
for the deadly virus though dozens have been trialled and proved to be
ineffective over the past years, an international symposium revealed over the
weekend in Beijing.
Robert Gallo, a scientist from University of Maryland Baltimore who
participated in the symposium, was the man that proved that the virus now known
as HIV causes AIDS. He commented on the difficulties facing the successful
development of an HIV preventative vaccine which include the following issues:
Testing cannot use an attenuated live version of the virus or an entire dead
version of the virus, forcing the use of subunits of the virus in testing.
There are enormous variations of the virus. Though vaccines can establish
antibodies in a person the virus is able to mutate to modify itself, causing the
antibody to become ineffective.
HIV is a retrovirus. Therefore it integrates its genes into the cell's genes
upon infection complicating vaccine development further.
He called all institutes of human virology throughout the world to take on
the responsibility of developing possible vaccines against HIV.
Although nobody can tell exactly which vaccines will be effective, some
vaccines exist that are worthy of further research and development, and these
need to be identified, he said.
Some of these potentially effective vaccines are being tested and developed
in China.
Currently, one vaccine has reached the human test stage for the first time in
China, in Guangxi Zhuang Autonomous Region.
Another vaccine, being developed by Shao Yiming, chief expert of the National
Centre for AIDS/STD, and his followers, has passed the animal test stage and is
applying for the human test stage now.
Chinese HIV vaccine research has learned many lessons from the experience of
other Chinese experts who have successfully developed vaccines for smallpox and
other endemic diseases, Shao said.
More than 150 domestic and overseas scientists gathered at the symposium,
which begun on Saturday and lasts until tomorrow, to discuss every possible
preventive measure against the virus which now infects nearly 40 million people
worldwide.
Besides the development of a vaccine, other preventive measures have been
proposed by experts at the symposium such as public education, the issuance of
clean needles, and methadone administration to encourage drug users to receive
drugs from a safer and cleaner source.
By the end of this year, it is hoped that 128 stations will have been
established in the country, with the role of administering free methadone to
drug users in a clean and controlled environment to reduce the chance of HIV
infection among drug users, Hao Yang, vice-director of the Disease Control
Department of the Ministry of Health, told China Daily.
Meanwhile, China should encourage people to take HIV tests, in particular
among blood donors, to prevent the spreading of the disease through blood
transfusions, said Robert Gallo.
In China, at least 23 per cent of the total reported HIV/AIDS sufferers are
infected through receiving contaminated blood in hospitals.
(China Daily 12/05/2005 page2)
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