HPV Vaccination Sends Genital Wart Cases Plummeting: Study04/19/13
THURSDAY, April 18 (HealthDay News) -- In the five years since
launching a nationwide human papillomavirus (HPV) vaccination
program among girls between the ages of 12 and 26, Australia has
seen a huge drop in the number of cases of genital warts, new
Among Australian girls in the targeted age range for
vaccination, the country saw genital wart cases plummet by 59
percent within just the first two years of the program's launch in
By aggressively vaccinating girls against HPV (which is
responsible for 90 percent of genital wart diagnoses), Australia
appears to have offered considerable protection not just to its
female population but also its men as well.
How? Researchers point to a phenomenon known as "herd immunity,"
whereby the immunity acquired by a certain segment of the
population -- in this case, women -- ends up protecting an
unvaccinated segment of the population (men).
In the same timeframe Australia has seen a 39 percent drop in
genital wart cases among heterosexual men as well.
"All indications are that the program has been an overwhelming success," noted study author Dr. Basil Donovan, who heads the sexual health program at the Kirby Institute of the University of New South Wales, in Sydney.
"But we won't be certain until HPV-related cancers [also] start dropping," he added, explaining that while genital warts tend to appear roughly three months following infection with HPV, "the incubation period from HPV infection to HPV-related cancer is typically at least 20 to 30 years."
HPV-associated cancers include cervical, penile, anal and throat
cancers, according to the U.S. Centers for Disease Control and
Donovan and his colleagues published their findings in the April
18 issue of the
To explore the impact of HPV immunization efforts in the
Australian context, the authors analyzed data collected from eight
different sexual health service organizations covering a period
from 2004 to 2011.
Collectively, the organizations had seen nearly 86,000
first-time patients in that timeframe, of whom about 9 percent were
diagnosed with genital warts.
By comparing the pre-vaccination period of 2004 to mid-2007 with
the vaccination period of mid-2007 through the end of 2011, the
team found a remarkable plunge in genital wart rates.
Among girls under the age of 21, that drop amounted to nearly 93
percent, while among those between 21 and 30 a decline of almost 73
percent was observed.
And while no appreciable genital wart rate drop-off took place
among women or men over the age of 30, among men under 30 a notable
dip was observed. Specifically, among heterosexual men below 21 the
drop amounted to almost 82 percent, while among those between 21
and 30 genital wart rates fell by more than 51 percent.
But is the Australian experience translatable to other countries
now engaged in various types of HPV vaccination programs?
Donovan said that how well other countries will fare in efforts
to dampen genital wart rates will depend on the degree of public
acceptance when it comes to HPV immunization efforts.
"There was little resistance to the HPV vaccine in Australia," he noted by way of explaining the program's success. By contrast, he suggested that the American public health effort -- which he characterized as "fractured" -- may very well produce less optimistic results, given the widespread controversy and reluctance to vaccinate that arose when the prospect of immunizing young girls was first proposed.
But in other countries, where the debate has been more muted,
Donovan sees better prospects. "As the U.K. is achieving vaccine
coverage rates at least as high as Australia," he said, "I would be
certain that they will soon be reporting comparable drops in
Commenting on the report, Dr. Jocylen Glassberg, an
obstetrician/gynecologist at Scott and White Healthcare in Round
Rock, Texas, said that "the take-home message is the vaccine is
"It will take many more years to see the same decline in cervical cancer rates due to the naturally slow progression of that disease process," she said. "But the vaccine works. The fact that genital wart rates were virtually zero after such a short time in women andmen, even in a program just aimed at vaccinated women, is a phenomenal result."
On that note, Glassberg pointed out that most vaccines do not
offer similar levels of protection. "Flu vaccines keep 80 percent
or so at bay," she explained. "This is almost 100 percent."
So, "aggressively educating the public should be key in the
U.S.A. as well," she concluded. "And getting the vaccines covered
in young women, and men, as a medical benefit could lead to a near
eradication of genital warts here as well."
In the United States, the vaccines Gardasil and Cervarix are
used to prevent HPV infection and are highly effective, according
to the U.S. National Institute of Allergy and Infectious
To learn more about HPV and genital warts, visit the
U.S. National Institute of Allergy and Infectious
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