CDC - Reports of Health Concerns Following HPV Vaccination - Vaccine Safety

CDC - Reports of Health Concerns Following HPV Vaccination - Vaccine Safety: Reports of Health Concerns Following HPV Vaccination
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* VAERS Limitations
* HPV Vaccine Safety
* VAERS Reports Following Gardasil®
* VAERS Reports Following Cervarix®
* Summary

VAERS Limitations

VAERS data cannot be used to prove a causal association between the vaccine and the adverse event. The only association between the adverse event and vaccination is temporal, meaning that the adverse event occurred sometime after vaccination. Therefore, the adverse event may be coincidental or it may have been caused by vaccination, however we cannot make any conclusions that the events reported to VAERS were caused by the vaccine.
HPV Vaccine Safety

There are two licensed HPV vaccines, Gardasil® and Cervarix®, available to protect against the types of HPV infection that cause most cervical cancers. Gardasil® was licensed for use in females, age 9-26 years in June 2006 and for males age 9-26 years in Oct 2009. Cervarix® was licensed for use in females age 10-25 in October 2009.

The safety of HPV vaccines was studied in clinical trials worldwide before licensure. For Gardasil® , over 29,000 males and females participated in these trials. For Cervarix®, over 30,000 females participated in several clinical trials.

Since licensure, 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 used in the U.S. These systems can monitor adverse events already known to be caused by vaccines, as well as detect rare adverse events that were not identified during pre-licensure clinical trials. The 3 systems are:

* 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 collaboration between CDC and 10 health care organizations which monitors and evaluates adverse events following vaccination.
* The Clinical Immunization Safety Assessment (CISA) Network– a collaboration between6 academic centers in the U.S. which conduct research on adverse events that might be caused by vaccines.


Reports to VAERS Following Gardasil®

As of June 22, 2011, approximately 35 million doses of Gardasil® were distributed in the U.S. and VAERS received a total of 18,727 reports of adverse events following Gardasil® vaccination: 17,958 reports among females and 346 reports for males, of which 285 reports were received after the vaccine was licensed for males in October 2009. VAERS received 423 reports of unknown gender. Of the total number of VAERS reports following Gardasil®, 92% were considered to be non-serious, and 8% were considered serious.
Non-serious adverse event reports

VAERS defines non-serious adverse events as those other than hospitalization, death, permanent disability, or life-threatening illness.

The vast majority (92%) of the adverse events reports following Gardasil® vaccination have included fainting, pain, and swelling at the injection site (the arm), headache, nausea, and fever. Syncope (fainting) is common after injections and vaccinations, especially in adolescents. Falls after fainting may sometimes cause serious injuries, such as head injuries, which can be prevented by closely observing the person for 15 minutes after vaccination.
Serious adverse event reports

Any VAERS report that indicated hospitalization, permanent disability, life-threatening illness, congenital anomaly or death is classified as serious. As with all VAERS reports, serious events may or may not have been caused by the vaccine.
Guillain-Barré Syndrome (GBS)

Guillain-Barré syndrome (GBS) has been reported after vaccination with Gardasil® . GBS is a rare neurologic disorder that causes muscle weakness. It occurs in 1-2 out of every 100,000 people in their teens. A number of infections have been associated with GBS. There has been no indication that Gardasil® increases the rate of GBS above the rate expected in the general population, whether or not they were vaccinated.
Blood Clots

There have been some reports of blood clots in females 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 factors.
Deaths

As of June 22, 2011 there have been a total 68 VAERS reports of death among those who have received Gardasil® . There were 54 reports among females, 3 were among males, and 11 were reports of unknown gender. Thirty two of the total death reports have been confirmed and 36 remain unconfirmed due to no identifiable patient information in the report such as a name and contact information to confirm the report. A death report is confirmed (verified) after a medical doctor reviews the report and any associated records. In the 32 reports confirmed, there was no unusual pattern or clustering to the deaths that would suggest that they were caused by the vaccine and some reports indicated a cause of death unrelated to vaccination.


VAERS Reports Following Cervarix®

Since licensed in October 2009, uptake of Cervarix® vaccination in the U.S. has been low. As of June 2011, there have been 39 VAERS reports of adverse events following Cervarix® vaccination in the U.S. The majority of these reports (97%) were considered to be non-serious.

Cervarix® has also been in use in other countries such as England and Europe prior to licensing from the FDA.


Summary

Based on all of the information we have today, CDC recommends HPV vaccination for the prevention of most types of cervical cancer. As with all approved vaccines, CDC and FDA will continue to closely monitor the safety of HPV vaccines. Any problems detected with these vaccines will be reported to health officials, healthcare providers, and the public and needed action will be taken to ensure the public's health and safety.