News (Updated
November 21, 2009)
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The researchers behind today's study, from Imperial College London, King's
College London and Royal Holloway,
The vaccine used an adenovirus, which normally causes the common cold, to enable
the vaccine therapy to travel around the body. Harmless HIV genes were then
inserted into the virus. It was thought that this would help the immune system
to learn to recognise and fight off HIV.
Today's study suggests that after receiving the trial vaccination, people who
had previously built up immunity to the adenovirus had an influx of immune cells
called CD4 T-cells homing in on their mucous membranes, as these cells prepared
to fight off a new adenovirus infection. Mucous membranes are found in areas
including the nose, mouth, vagina and gut. HIV naturally infects CD4 T-cells, so
this inadvertently provided HIV with an abundance of potential new homes at the
sites where the virus would naturally enter the body during sexual intercourse,
thereby increasing people's risk of infection.
The researchers say their findings are a warning for scientists developing
adenovirus vaccines against other diseases, as the same effect occurs with
other, perhaps all, adenovirus subtypes.
Adenovirus infection is common and there are 51 known human strains. Around half
of all adults in the developed world and about 90 percent of individuals in
sub-Saharan
Today's findings may have implications for HIV, malaria and TB vaccines
currently being developed
Preliminary results of the vaccine trial showed that people who had previously
been infected with the adenovirus used in the trial had a significantly higher
risk of being infected with HIV following the vaccine compared to people who
were given a placebo.
Dr Steven Patterson, who is the corresponding author of the study from the
Division of Investigative Science at Imperial College London, said: "HIV is
a huge threat to global health, with 2.7 million people becoming infected every
year. We were all hopeful that the STEP trial would be a success, so when the
researchers published their results and the trial was halted, we were all very
surprised and disappointed. Scientists use adenoviruses in all sorts of vaccines
and we did not expect this result. It was vital to discover what caused this
increase in HIV infection risk so we could avoid the same problem in future
trials.
"Our research suggests that the adenovirus-based HIV vaccine effectively
instructs the cells that HIV infects to gather round exactly where HIV is likely
to be introduced. This is clearly worrying for this kind of vaccine. Scientists
are currently developing adenovirus-based vaccines to protect people against TB
and malaria as well as HIV, but they may have to rethink these vaccines if the
effect we describe in our new paper is a problem for all of them," added Dr
Patterson.
The researchers measured antibodies against adenovirus type 5 ( Ad-5 ) and
adenovirus type 11 ( Ad-11 ) in 20 healthy volunteers to determine who had been
infected. They then took samples of the volunteers' immune cells and grew them
in the laboratory to see whether their CD4 cells would recognise Ad-5 and Ad-11.
When the researchers added adenoviruses to the tissue cultures, they found that
the viruses activated the CD4 cells and caused them to grow and replicate. They
found that the newly generated CD4 cells had particular kinds of molecules on
their surface that enabled them to migrate to mucosal membranes.
The results also showed that CD4 cells can recognise and react to another
distinct subtype of adenovirus, regardless of which subtype the person was
infected with initially. The authors say this means all subtypes of adenovirus
are likely to be unsuitable in HIV vaccines.
By MIKE STOBBE, AP Medical
Writer Mike Stobbe, Ap Medical Writer
Nov 16, 2009
Last year there were 1.2
million new cases of chlamydia, a sometimes symptomless infection that can lead
to infertility in women. It was the most ever reported, up from the old record
of 1.1 million cases in 2007.
Better screening is the
most likely reason, said Dr. John M. Douglas Jr. of the U.S. Centers for Disease
Control and Prevention.
Syphilis, on the verge of
being eliminated in the
Unlike chlamydia, health
officials think syphilis cases actually are increasing. Syphilis rates are up
among both gay men and heterosexuals, said Douglas, director of the CDC's
Division of STD Prevention.
Syphilis can kill if
untreated, but chlamydia is not life-threatening. Neither is gonorrhea, which
seams to have plateaued in recent years. Gonorrhea cases dropped to about
337,000 cases in 2008, down from about 356,000 cases.
Girls, ages 15 through 19,
had the largest reported number of chlamydia and gonorrhea cases, accounting for
more than one in four of those cases. But they're often screened more than other
people, since 1993 federal recommendations that emphasize testing for sexually
active women age 25 and under.
The government estimates
there are roughly 19 million new cases of sexually transmitted disease annually.
Experts say the most common is HPV, human papillomavirus, which can cause
genital warts, cervical cancer and other cancers.
The government doesn't ask
doctors to report every HPV case, but estimates the virus causes 6.2 million new
cases each year. That is an old estimate, based on data from 2000, before a
vaccine against some types of HPV came on the market in 2006.
The CDC estimates there
are 1.6 million new cases of genital herpes each year, but that too is an old
estimate for a non-reportable disease.
The agency also estimates
there about 56,000 new cases of HIV each year.
By LAURAN NEERGAARD,AP
Medical Writer - November 21, 2009
New guidelines by the
The change comes amid a
separate debate over when regular mammograms to detect breast cancer should
begin, in the 40s or the 50s. The timing of the Pap guidelines is coincidence,
said ACOG, which began reviewing its recommendations in late 2007 and published
the update Friday in the journal Obstetrics & Gynecology.
While the two sets of
recommendations are unrelated, they come at a time of intense debate over
health-care reform. Mammograms in particular have drawn broad attention in
Congress, reflecting a more than decade-long debate in the cancer community
about how best to perform mammograms.
Republicans sought to
connect the mammogram recommendations to the health-care overhaul, contending
that such findings are the way that medical rationing starts.
Under the pending
legislation, "nothing would prohibit the federal government from deciding
if tests, treatments and procedures are too expensive, and therefore,
unnecessary," Sens. Jon Kyl of Arizona, the Republican Whip, and Tom Coburn
of Oklahoma, a physician, said in a joint statement.
But the Pap guidelines
promise to be far less controversial as doctors for years have been told to
perform fewer Paps among many women over 30, to cut back on unneeded care for
the least at risk _ and there's growing understanding that over-treating younger
women is an issue, too.
"The tradition of
doing a Pap test every year has not been supported by recent scientific
evidence," said Dr. Alan Waxman of the
The guidelines also say:
_Routine Paps should start
at age 21. Previously, ACOG had urged a first Pap either within three years of
first sexual intercourse or at age 21.
_Women 30 and older should
wait three years between Paps once they've had three consecutive clear tests.
Other national guidelines have long recommended the three-year interval; ACOG
had previously backed a two- to three-year wait.
_Higher-risk women, such
as those with HIV, other immune-weakening conditions or previous cervical
abnormalities, need more frequent screening.
Paps can spot
pre-cancerous changes in the cervix in time to prevent invasive cancer, and
widespread use has halved cervical cancer rates in the
Cervical cancer is caused
by certain strains of the extremely common sexually transmitted virus called HPV,
for human papillomavirus. There is a new HPV vaccine that should cut cervical
cancer in the future; ACOG's guidelines say for now vaccinated women should
follow the same Pap guidelines as the unvaccinated.
But the updated guidelines
reflect better understanding of HPV. Infection is high among sexually active
teens and young adults. Women's bodies very often fight off an HPV infection on
their own without lasting harm, although it can take a year or two. The younger
the woman, the more likely that HPV is going to be transient.
Moreover, ACOG cited
studies showing no increased risk of cancer developing in women in their 20s if
they extended Pap screening from every year to every two years.
As for adolescents, ACOG
said cervical cancer in teens is rare _ one or two cases per million 15- to
19-year-olds _ while HPV-caused cervical abnormalities usually go away on their
own. Treating them unnecessarily increases the girls' risk of premature labor
years later, and preterm birth is a growing national problem.
Nov 20, 2009
WASHINGTON (AFP) - Women
should not get their first cervical cancer screening before age 21, the leading
Pushing back the age of
the first screening would help avoid giving teen girls unnecessary treatment,
which can have "economic, emotional and future childbearing
implications," according to the guidelines issued by the American College
of Obstetricians and Gynecologists (ACOG).
ACOG previously
recommended that cervical screening begin three years after first sexual
intercourse or by age 21, whichever occurred first.
But the guidelines were
revised because "screening for cervical cancer in adolescents only serves
to increase their anxiety and has led to overuse of follow-up procedures for
something that usually resolves on its own," said Alan Waxman, who led the
ACOG team that drew up the recommendations.
The new guidelines also
recommend that most women under 30 be screened every two years instead of
annually, and that women older than 30 who have had three consecutive negative
cervical cytology test results be screened once every three years instead of
yearly.
Certain women, including
those carrying the HIV virus, with suppressed immune systems or who have been
treated for cervical cancer, may need to be screened more often, the guidelines
said.
ACOG made its revisions
after a data review showed that "screening at less frequent intervals
prevents cervical cancer just as well, has decreased costs and avoids
unnecessary interventions that could be harmful," Waxman said.
Cervical cancer rates have
fallen by more than half in the past 30 years in the
In 1975, nearly 15 women
per 100,000 in the
Thirty-one years later, in
2006, the rate was 6.5 women per 100,000.
The new recommendations
are to be published in the December issue of Obstetrics and Gynecology.
(AP) – 20 November, 2009
Under the deal, OraSure
settles the lawsuit filed against the company by Inverness and Church &
Dwight Co., with
The companies are also
granting each other distribution rights to certain products, including HIV
hepatitis C tests, and flu tests.
OraSure now expects a
fourth-quarter loss of 10 cents to 11 cents per share because of the legal
charge.
On average, analysts
surveyed by Thomson Reuters forecast a quarterly loss of 8 cents per share. The
estimates typically exclude one-time charges.
Shares of OraSure fell 15
cents, or 3.5 percent, to $4.19 in midday trading. The stock has traded between
$2.16 and $4.55 over the last 52 weeks.