Gardasil

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Gardasil is the world's first vaccine against cervical cancer and other diseases caused by certain types of the human papillomavirus (HPV). The vaccine, marketed by Merck & Co., is designed to prevent infection with HPV types 16, 18, 6, and 11. HPV types 16 and 18 cause about 70% of HPV-related cervical cancer cases. HPV types 6 and 11 cause about 90% of genital wart cases.

1 Biotechnology
2 Indications
3 Administration
4 Long term impact
5 Clincial Trials
6 References
7 External links

[edit] Biotechnology

The HPV major capsid protein, L1, can spontaneously self-assemble into virus-like particles (VLPs) that resemble authentic HPV virions. Gardasil contains recombinant VLPs assembled from the L1 proteins of HPVs 6, 11, 16 and 18. Since VLPs lack the viral DNA, they cannot induce cancer. They do, however, trigger an antibody response that protects vaccine recipients from becoming infected with the HPV types represented in the vaccine.

[edit] Indications

Gardasil is a prophylactic HPV vaccine, meaning that it is designed to prevent the initial establishment of HPV infections. In worldwide clinical analyses, however, women who were already infected with 1 or more of the 4 HPV types targeted by the vaccine (6, 11, 16, or 18) were protected from clinical disease caused by the remaining HPV types in the vaccine. For maximum efficacy, it is recommended that girls receive the vaccine prior to becoming sexually active. Since Gardasil will not block infection with all of the HPV types that can cause cervical cancer, the vaccine should not be considered a substitute for routine Pap smears.

Gardasil also may be used in preventing HPV 16/18-caused anal cancer.^[1] A 2005 study in San Francisco found that 95 percent of HIV-infected gay men also had anal HPV infection, of which 50 percent of had precancerous HPV-caused lesions. ^[2]

[edit] Administration

After undergoing extensive clinical trials, Gardasil was approved by the US Food and Drug Administration (FDA) on June 8, 2006, and is currently available.^[3] The drug is also approved for use in Australia, New Zealand, Canada, and countries of the European Union.

Gardasil is given in 3 injections over 6 months, namely at enrollment, and 2 and 6 months later.

Adverse effects can include local limited reactions at the site of injection, such as pain, swelling, redness, and itching.

On June 29, 2006, a panel of experts, the Advisory Committee on Immunization Practices, gave their approval for the vaccination of Gardasil on children as young as 9 years old. The ACIP recommended that Gardasil be placed on the childhood immunization schedule at the 11 to 12 year old visit. They also recommended that the vaccine be included in the federal Vaccines for Children Program, which would provide the vaccines free of charge to children under the age of 18 who are uninsured. ^[4]

Legislation has been introduced in the state of Michigan to require Gardasil. If passed, this would make them the first state to require that its school children be vaccinated.^[5]

Australia's government announced on 29/11/2006 that they will provide this vaccination to all 12-13 year-old girls from 2007.

[edit] Long term impact

One unknown property of the vaccines now being researched is their longevity. Since the studies have been of short duration, it is unknown whether the vaccines will last just a few years or for much longer. Further study over time is required to answer this question.

270,000 women died of cervical cancer worldwide in 2002.^[6] According to the American Cancer Society, 3,700 of those deaths occurred in the United States.^[7]Acting FDA Administrator Dr. Andrew von Eschenbach said the vaccine will have "a dramatic effect" on the health of women around the world. ^[3]

Merck and CSL Limited are expected to market Gardasil as a cancer vaccine, rather than an STD vaccine. It remains unclear how widespread the use of the three-shot series will be, in part because of its $360 list price ($120 each for 3 shots). There has also been some opposition to the vaccine by religious conservatives, who fear that it will have the unintended consequence of encouraging sexual activity they consider immoral. Merck and CSL have also suggested that governments make vaccination with Gardasil mandatory for school attendance, which has upset some conservative groups. ^[3] ^[8]

[edit] Clincial Trials

Merck & Co. conducted a Phase III study named FUTURE II. This clinical trial was a randomized double-blind study with one controlled placebo group and one vaccination group. Over 12,000 women aged 16-26 from 13 countries participated in the study. Each woman was injected with either Gardasil or a placebo on Day 1, Month 2, and Month 6. In total, 6,082 women were given Gardasil and 6,075 received the placebo. ^[9]