News (Updated
January 8, 2012)
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Thu, Jan 5 2012
By Julie Steenhuysen
CHICAGO (Reuters) - An
experimental vaccine helped protect monkeys from an especially deadly form of
the AIDS virus, raising new hope for an effective vaccine in people,
The vaccine reduced the
risk of infection by 80 percent among monkeys exposed to a primate version of
the virus, while monkeys that became infected had lower amounts of the virus in
their blood, the team reported in the journal Nature.
"It is an important
advance in knowledge," Dr. Anthony Fauci, director of the National
Institute of Allergy and Infectious Diseases, said in a telephone interview.
Scientists are especially
excited because the study helped identify a key part of the immune system that
is needed to offer protection from the human immunodeficiency virus or HIV that
causes AIDS.
"It is nailing down in
a more precise way what kind of an immune response a vaccine needs to induce to
protect against the acquisition of infection as well as suppression of virus if
someone happens to get infected," Fauci said.
The result is promising
enough that the researchers are planning to test the vaccine in humans next
year.
Efforts so far to make an
AIDS vaccine have not been successful but a 2009 study in
The researchers used
weakened versions of two viruses commonly used in vaccine development -- a
common cold virus called an adenovirus and a smallpox virus -- to deliver the
primate version of the HIV antigen into the body and trigger an immune response.
"The vaccines we
tested have had very extensive experience in the clinic, which means the
transition from the animal work to the human work will be very easy," said
Colonel Nelson Michael, director of the U.S. Military HIV Research Program at
the Walter Reed Army Institute of Research, who worked on both the study in
After vaccinating the
monkeys, the team exposed the animals to an aggressive version of simian
immunodeficiency virus, or SIV.
"This was really a
high bar to get over," Michael said in a telephone interview. "We were
excited to see these vaccine types protected these animals."
After repeated exposure to
SIV, eventually most of the animals did become infected but even then, the
vaccine appeared to offer added protection.
"We saw two things
that were really important. A protection against infection but even in animals
that became infected, we saw reduced levels of virus," Michael said.
Next, the team did a series
of tests to see what parts of the monkeys' immune system became active. They
found that a key portion of a gene called an envelope, which the virus uses to
get inside cells, was critical to protecting the animals.
"This is going to be
the anchor for a next generation of vaccines that will propel us past
He cautioned that the
studies so far are in monkeys and the real test will be human trials, which he
expects to start in January 2013.
The group is working
closely with vaccine maker Crucell, a unit of Johnson & Johnson.
There is no cure for AIDS
but cocktails of drugs can keep the disease at bay for many years. New research
shows they can prevent the virus from spreading to sexual partners.
But because HIV is spread
in so many ways -- during sex, on needles shared by drug users, in breast milk
and in blood -- there is no single easy way to prevent infection and a vaccine
is still considered the best hope for conquering the virus.
Some 34 million people
globally are infected with HIV and more than 25 million people have died of
AIDS, according to the United Nations agency UNAIDS.
(Editing by Bill Trott)
Jan 2 2012
By Julie Steenhuysen
CHICAGO (Reuters) - Some
adolescent girls who get the HPV vaccine to prevent cervical cancer wrongly
think they no longer need to practice safe sex,
The study, published in
the Archives of Pediatric & Adolescent Medicine, shows the need for better
education about the vaccines and their limitations.
Merck's Gardasil and
GlaxoSmithKline's Cervarix vaccines protect against strains of the
humanpapilloma virus or HPV that cause cervical cancer. Gardasil also protects
against some strains of the virus that cause genital warts.
But neither vaccine can
prevent other forms of sexually transmitted diseases such as syphilis, gonorrhea
or human immunodeficiency virus or HIV that causes AIDS.
And HPV vaccines can only
prevent HPV infections; they do not treat active infections.
Most girls who get the
vaccine know its limitations, the researchers said, but the vaccines are
recommended for all girls aged 11 to 12, and overestimating their effect could
increase a young woman's risk of contracting other sexually transmitted
diseases.
For the study, Dr. Tanya
Kowalczyk Mullins of Cincinnati Children's
Overall, most adolescent
girls said they believed it was important to practice safe sexual behaviors
after getting the shot. But a small group of girls -- 23.6 percent -- believed
they were less at risk for getting sexually transmitted diseases after getting
the vaccine.
Factors associated with
this view included having less information about the vaccine and about HPV
infections, less concern about contracting HPV and lack of condom use at last
sexual intercourse with a male partner.
The findings suggest
doctors need to do a better job of educating girls and their mothers about the
vaccine.
"Clinicians
discussing HPV vaccination with girls and their mothers may need to emphasize
the limitations of the vaccine and to specifically address that the vaccine does
not prevent other sexually transmitted infections," the team wrote.
HPV is the most common
sexually transmitted infection in the
The authors said the study
was limited in that subjects came from a single urban clinic serving low-income
clients so the findings may not apply to more general populations.
The study was funded by
the National Institutes of Health, but some authors have been awarded research
grants from Merck.
Wed, Dec 21 2011
(Reuters) -
The safety and
effectiveness of the drug was evaluated in a clinical trial of 96 children and
adolescents of ages 2-18 years with HIV-1 infection, the U.S. Food and Drug
Administration said in a statement.
The drug, Isentress, was
first approved for use in adult patients in October 2007.
(Reporting by Shailesh
Kuber in
08 Jan 2012
According to a study in which three trials of antiviral therapy to treat genital
herpes were combined, the herpes simplex virus type 2/HSV-2 can reactivate in
'breakthrough episodes' even when doses of antiviral therapy are high. The study
is published Online First in The Lancet and suggests that new therapies should
be conducted to successfully prevent further transmission of this common
infection, which affects one in five people.
HSV-2 infection is characterized through ulcers in the skin or mucus membranes
of the mouth, lips, or genitals, and even though most people do not show obvious
symptoms, they are still able to shed the virus and transmit it to sexual
partners.
HSV-2 hides in the nervous system of the infected host and can reactivate
periodically. When the virus is re-activated in a nerve cell, it is transported
along the nerve to the skin, where it is replicated anew causing 'shedding' and
new sores. Intensive genital secretion collection demonstrates that HSV shedding
episodes are three-times more frequent than was previously thought.
Dr. Christine Johnston at the
Other patients received the standard dose of valaciclovir 500 mg daily compared
with a high dose of aciclovir 800 mg three times daily, and those who were given
a standard-dose of valaciclovir compared with a high dose of valaciclovir 1 g
three times daily.
The findings demonstrated that short episodes of subclinical, i.e. symptom free
shedding persist with both standard-dose and high-dose aciclovir and
valaciclovir and even though HSV shedding was lowered by 50% with the highest
doses of valaciclovir compared with the standard dose of valaciclovir, the rate
of breakthrough shedding incidences remained unchanged with approximately 16 to
20 incidences each year.
The researchers explain:
"Our finding that
high-dose valaciclovir increases the kinetics of viral clearance, but not
expansion, supports the hypothesis that these antiviral drugs do not suppress
the release of virions into the genital tract. That we could not eliminate or
even alter the frequency of shedding episodes with high-dose valaciclovir
suggests that the maximum benefit of shedding reduction has probably been
reached for currently available antiviral drugs."
They summarize their findings concluding, that:
"Although currently
available anti-HSV therapy benefits patients by preventing clinical HSV
recurrences, suppressive therapies with greater potency, including antiviral
drugs or immunotherapy in the form of therapeutic vaccines, are needed to
provide substantial public health benefits, such as prevention of HSV-2
transmission and HIV-1 acquisition and transmission."
According to a linked comment by Dr. Philippe Van de Perre and Dr. Nicolas Nagot
INSERM U 1058 in Montpellier, France, and the Université Montpellier 1 in
Montpellier, France, even though the development of new antiviral drug classes,
such as helicase-primase inhibitors is important, such drugs would require a
good long-term coverage and adherence to successfully prevent shedding and
onward transmission of HSV-2.
They explain and conclude:
"These needs are
unlikely to be met because about 20% of the general population is infected with
HSV-2 in the
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