When federal finance minister Jim
Flaherty announced his budget this spring, provincial
health officials might have been forgiven for thinking
the Easter Bunny had come early.
One headline-grabber was the surprise
announcement of a $300 million package to jumpstart
provincial immunization programs against human papillomavirus
(HPV), the cause of the overwhelming majority of cervical
cancers. The vaccine, Gardasil, protects against HPV
types 6, 11, 16 and 18, of which the latter two are
oncogenic.
All women and girls aged nine to
26 would be targeted, Ottawa said. The provinces’
delight abated somewhat after they did the sums, and
realized that $300 million would only cover enough $425
shots to give one to each girl currently in the 9-12
age group. But, putting any ill-feelings aside, most
provinces immediately set to work developing plans to
immunize young schoolgirls. This summer Ontario, Nova
Scotia, Newfoudland and PEI announced programs to start
with this school year; BC may also have a program ready
in time.
TOO
SOON?
Doctors, parents, politicians, drug makers, everyone
was happy — until this month, that is, when a bombshell
landed on the CMAJ website. Four experts in epidemiology
and women’s health asked a number of pointed questions
about the evidence base, the lack of clear stated goals
and the haste with which these decisions are being made.
The article appears in the August 28 print edition,
which is largely devoted to HPV.
“My concern was with the medical
evidence,” says lead author Abby Lippman, PhD,
an epidemiologist at McGill. “I couldn’t understand
why there was suddenly such a rush to do this when cervical
cancer only kills about 400 people a year in Canada,
and most of them are dying because of lack of treatment.
I couldn’t see anything like the sort of evidence
one would expect to support a decision like this.”
The criticisms are of a sort we
hear all too often these days. The available research
data comes from the manufacturer’s trials. The
longest follow-up was only five years. The least research
was conducted in the very age group we are now about
to immunize, girls aged 9-12. Only about 100 girls in
this age group were trial subjects, and they had the
shortest follow-up.
“If we don’t know the
duration of the vaccine,” says Dr Lippman, “how
can we predict the costs of the program?” She also
points out that no statement has yet defined the goals
of the program. “Is it herd immunity they’re
after? If so, they should be looking at immunizing men
and boys too. Is it a reduction in cervical cancer?
Gardasil only eradicates the HPV types responsible for
slightly over twothirds of cervical neoplasms.”
Above all, she asks, what’s the rush? “Most
people get HPV at some point, and it clears spontaneously
in the vast majority of cases. There is no epidemic
of cervical cancer. The Canadian Immunization Committee
(CIC) is bringing out recommendations on HPV at the
end of the year. Why couldn’t they wait for that?”
The federal co-chair of that committee,
Dr Theresa Tam, an infectious disease specialist who
also heads the Immunization and Respiratory Infections
Division of the Public Health Agency of Canada, acknowledges
gaps in the knowledge. “It’s true that for
the primary endpoint, cervical cancer, there is no direct
data from the youngest girls, because it would be unethical
to conduct the necessary investigations in that age
group,” she says. “So antibody response is
used as a ‘bridging indicator.’ But in fact,
the antibody response was particularly good in the youngest
girls. That’s a very promising sign.” Schoolgirls
are a “captive audience” who give a program
“more bang for the buck,” she notes. “Once
they’ve left school, immunization becomes hit-and-miss.”
She acknowledged the dearth of follow-up data beyond
five years. “We don’t rule out booster shots
in the future,” she says, adding that shots for
men and boys are also theoretically possible. She has
no problem, though, with provinces getting started now.
“Our recommendations will hopefully serve to bring
some consistency on the national level.” As for
the program’s goal: “There will be a clear
statement on the program goal when CIC finishes its
work,” says Dr Tam, “but I’m afraid I
can’t pre-empt it.”
“I found the CMAJ article
to be full of useful information,” adds Dr Tam.
“We did look at these questions, the potential
downsides, the gaps in the knowledge, but at the end
of the day we felt we still had a very good vaccine
here.”
The medical debate over Gardasil,
however, has become subsumed in a larger political fight.
The trouble began south of the border.
GOV’T
CONFLICTS
All of the proposed programs in Canada are comprehensive
but voluntary. In the US, the push was to get states
to pass mandatory vaccination laws. The first state
to actually do so was Texas. It then emerged that Texas
governor Rick Perry received $5,000 for his campaign
from Gardasil’s manufacturer Merck on the day he
met with aides to discuss the project. Several Texas
lawmakers also got payments. The state legislature has
since overturned the plan.
The same thing was happening in
dozens of states considering mandatory programs. The
end came swiftly, with a letter from the American Academy
of Pediatrics asking Merck to desist in its lobbying,
because it was doing more harm than good. The company
agreed.
There’s evidence something
similar has been going on here. CanWest investigative
reporter Shelley Page discovered that shortly before
the budget announcement, a former aide to Prime Minister
Stephen Harper, Ken Boessenkool, registered as a Merck
lobbyist. Shortly before Ontario announced its immunization
plan, Jason Grier, former executive assistant to Ontario’s
health minister George Smitherman, had also registered
as a Merck lobbyist. The Society of Obstetricians and
Gynaecologists of Canada came out in support of the
program, but they also acknowledged that their research
on the issue had been funded by a $1.5 million grant
from Merck.
“I’m not saying that
HPV immunization is necessarily a bad thing,” says
Dr Lippman. “I am saying this is no way to make
major public health decisions.”
|
