Human Papillomavirus Vaccination
Jessica A Kahn Associate Professor of Pediatrics, Cincinnati Children's Hospital Medical Center and the
University of Cincinnati College of Medicine
Status of Licensing and Vaccination
Recommendations
On 8 June 2006, the US Food and Drug
Administration (FDA) approved the use of the HPV
6,11,16,18 vaccine, GARDASIL (Merck & Co.,
Inc., Whitehouse Station, NJ) for girls and women
nine to 26 years of age. Data on immunogenicity
and efficacy in male vaccine trial participants should
be available within the next two years, and at that
point the FDA may approve vaccination of boys and men as well. The Advisory Committee on
Immunization Practices (ACIP) will meet at the end
of June 2006 to finalise national recommendations
for vaccination of girls and women in the US.
According to proceedings of a recent ACIP
meeting, the organisation will likely recommend
that the vaccine be targeted toward 11- to 12-yearold
girls, with vaccination of nine- to ten-year-olds
under some circumstances and catch-up
immunisation of 13- to 26-year-old girls and
women. Other professional organisations, such as
the American Academy of Pediatrics, will also
publish recommendations for vaccination.
GlaxoSmithKline is expected to submit an
application to the FDA for approval of the HPV
16,18 vaccine (CERVARIX) by the end of 2006.
Key Issues for Vaccine
Delivery and Uptake
The public health impact of HPV vaccination will
depend on widespread vaccination of young
women, ideally prior to sexual initiation. However,
a number of challenges remain. First, most women
have a poor understanding of HPV infection and its
link to cervical cancer. Paediatricians and family
physicians, who will be recommending HPV
vaccines, may not have extensive knowledge about,
or experience with, HPV-related disease. Reaching
the most vulnerable adolescents will be difficult, e.g.
those who are homeless, do not attend school, or do
not have access to a healthcare provider. Even
among those adolescents who have a consistent
healthcare provider, it will be challenging to ensure
that they receive three immunisations over a sixmonth
period. The cost of vaccination, which will
likely exceed US$300 for the series, may be a
significant barrier to vaccination, particularly if
third-party payors or the Vaccines for Children
Program do not provide coverage. Furthermore,
previous experience with new vaccines has
demonstrated that vaccine uptake generally is slow
in the absence of state legislation mandating
immunisation. It is unlikely that mandated
immunisation will occur in the near future, both
because it will take time to pass legislation and
because some organisations may oppose mandated
immunisation. Finally, successful vaccine uptake will
depend upon HPV vaccine acceptability among
providers, parents, and adolescents.
Despite initial concerns about HPV vaccine
acceptability, recent studies suggest that the
majority of providers, parents, and young adults
find HPV vaccination to be acceptable. In national
studies of US paediatricians and family physicians,
approximately 75% indicated that they would
recommend an HPV vaccine if licensed. Physicians
identified parental concerns about HPV vaccination
as potential barriers to vaccination. However, most
parents are supportive of vaccination: 67–83% of
parents participating in recent studies indicated that
they would agree to have their daughters
vaccinated.
Key factors in parents’ decisions to vaccinate their
children include a desire to protect their child from
cancer; beliefs about the severity of HPV-related
disease and their child’s susceptibility to HPV
infection; attitudes about vaccine safety and efficacy;
physician recommendation for vaccination; and
personal experience with HPV-related diseases.
Although some parents are concerned about a
possible adverse impact of HPV vaccination on
sexual risk behaviours and compliance with Pap
screening, there is currently no evidence that
suggests adolescents will practice riskier behaviours
if vaccinated.
Public health initiatives and vaccine-related
policies may help to maximise vaccine uptake and
thus the public health impact of vaccination.
Educational materials must be developed for
physicians and nurses, both to provide information
about vaccination and guide them in terms of
addressing any parental concerns. Educational
materials for parents and adolescents that are
culturally sensitive and promote healthy behaviours
are urgently needed. Young women must
understand that HPV vaccines will not prevent the
acquisition of other STIs, so they should continue
to try to minimise STI exposure through
abstinence, limiting sexual partners and consistent
condom use. Young women must also understand
that they should continue to obtain regular Pap
tests even after vaccination. The primary rationale
for continued Pap screening is that the vaccines
will not prevent all cases of cervical cancer, because
high-risk types not contained in the vaccines cause
approximately 30% of cervical cancers. Pap
screening after vaccination will also be important
because vaccine efficacy may be compromised if
women have been infected previously with HPV
types contained in the vaccines, if they do not
receive all three immunisations, or if immunity
wanes over time. Other strategies that may
promote vaccine uptake should be explored, such
as vaccination in alternative settings (e.g. schoolbased
health centres), legislation to mandate
vaccination for school entry and efforts to promote
insurance coverage for HPV vaccines.
