Cervical cancer vaccines:

Cervical cancer is cancer that starts in
the cervix, the lower part of the uterus
(womb) that opens at the top of the

Gardasil by Merck,

GlaxoSmithKline Plc’s Cervarix;

There are two HPV vaccines, Gardasil
and Cervarix, available to protect
against the types of HPV that cause
most cervical cancers.

The safety of the HPV vaccine was
studied in clinical trials before it was
licensed. For Gardasil, over 29,000
males and females participated in
these trials. Cervarix was studied in
over 30,000 females participating in
several clinical trials performed all over
the world. Cervarix has also been in
use in other countries such as England
and Europe prior to licensing from the
Food and Drug Administration (FDA).

CDC and FDA have been closely
monitoring the safety of HPV vaccines.
There are 3 systems used to monitor
the safety of vaccines after they are
licensed and being used in the U.S.

•The Vaccine Adverse Event Reporting
System (VAERS)--a useful early
warning public health system that
helps CDC and FDA detect possible
side effects or adverse events
following vaccination.
•The Vaccine Safety Datalink (VSD)
Project--a project between CDC and 8
health organizations evaluate and
monitor adverse events following
•The Clinical Immunization Safety
Assessment (CISA) Network--a project
between 6 academic centers in the U.
S. which conduct research on adverse
events that might be caused by

Since licensed in October 2009,
VAERS has received 3 adverse event
reports occurring in the U.S. following

As of May 31, 2010, approximately
29.5 million doses of Gardasil were
distributed in the United States.

As of May 31, 2010, there were 16,140
VAERS reports of adverse events
following Gardasil vaccination in the
United States. Of these reports, 92%
were reports of events considered to
be non-serious, and 8% were reports
of events considered serious.
Based on all of the information we
have today, CDC recommends HPV
vaccination for the prevention of most
types of cervical cancer.
All serious reports (8%) for Gardasil
have been carefully analyzed by
medical experts. Experts have not
found a common medical pattern to the
reports of serious adverse events
reported for Gardasil that would
suggest that they were caused by the

Guillain-Barré Syndrome (GBS) has
been reported after vaccination with
Gardasil. GBS is a rare disorder that
causes muscle weakness. It occurs in
1-2 out of every 100,000 people in
their teens. A number of infections can
cause GBS. There has been no
indication that  Gardasil increases the
rate of GBS in girls and women above
the rate expected in the general
population, whether or not they were

Blood Clots

There have been some reports of
blood clots after receiving Gardasil.
These clots have occurred in the
heart, lungs, and legs. Most of these
people had a risk of getting blood
clots, such as taking oral
contraceptives (the birth control pill),
smoking, obesity, and other risk


As of May 31, 2010, there have been
53 U.S. reports of death among
females who have received Gardasil.
Twenty nine of these reports have
been confirmed and 24 remain
unconfirmed due to no identifiable
patient information in the report such
as a name and contact information to
confirm the report. Confirmed reports
are those that scientists have followed
up on and have verified the claim. In
the 29 reports confirmed, there was no
unusual pattern or clustering to the
deaths that would suggest that they
were caused by the vaccine.