Human papilloma virus (HPV)
is strongly associated with the development of cancer of
the cervix in females. There are several cancer-causing HPV strains.
Vaccination against the virus could play a role in the prevention of cervical
cancer. Currently, HPV vaccine is available as Gardasil®
, Gardasil 9®
. Three doses of
vaccines are advised in adolescent girls around the ages of 11 to 12 years,
with the second dose given 1 to 2 months after the first dose and the third
dose about 6 months after the first dose. Some countries including Britain have
approved the use of only 2 doses of the vaccine.
Researchers from the HPV-IMPACT Working Group
evaluated the impact of the HPV vaccine in preventing cervical cancer
. They found that the rate of high-grade cervical lesions which
often progress to cancer
(cervical intraepithelial neoplasia grade 2, 3,
and adenocarcinoma in situ
reduced in the period between 2008 to 2012 in several cities of the United
, which was the time following the introduction of the vaccine. The change was particularly noted in the
age groups of 18 to 20 years
, and also in the 21 to 29 years group.
However, no major change was noted in the age group of 30-39 years.
Though this reduction in the pre-cancerous changes can
be attributed to the impact of vaccination, the researchers caution that it could also be due to the low screening
rates in the younger age groups
during the same post-vaccination period. Currently,
screening for cervical cancer is not routinely recommended in girls below the
age of 21 years. Consequently, the researchers found a large decrease in
screening among the 18 to 20 years age group, with smaller declines in the
other age groups.
The US Preventative Task Force currently recommends
cervical cancer screening with Pap smear in women aged 21 to 65 every 3 years.
If women between the ages of 30 and 65 years want to be screened less
frequently, they have the option of choosing a combination of Pap smear and
can be done every 5 years.
Long-term studies are required before one can say for
sure that the HPV vaccine does have a significant effect in preventing cervical
cancer. These studies also have to consider that the changes in screening
recommendations could affect their study results as well.