在全世界范围内，宫颈癌为女性癌症死因的第二位杀手，每年有50万人确诊，约30万人因此死亡。2005年，美国约有1万例新确诊的宫颈癌患者，约有3700例患者死亡。在大多数人中，人乳头瘤病毒可于感染后自行消失。然而，少数情况下，某些高危类型的人乳头瘤病毒如果未被检出和治疗，可以导致宫颈癌。此外，某些低危类型的人乳头瘤病毒可以导致尖锐湿疣。美国每年约有100万例尖锐湿疣。美国每年约有470万女性由于巴氏涂片检查（Pap）结果异常需要进行随访。其中，至少有300万例此类异常结果是由某些人乳头瘤病毒导致的。
GARDASIL（针对四种类型的人乳头瘤病毒，即6型、11型、16型、18型的细胞重组疫苗）的生物制剂GARDASIL是默沙东公司研制的宫颈癌疫苗。该疫苗可以预防四种类型的人乳头瘤病毒（HPV）感染：16型和18型以及6型和11型。

据估计70%的宫颈癌病例由16型和18型病毒 引发；90%的尖锐湿疣病例由6型和11型病毒引发。

6月8日，美国联邦食品和药品管理局批准首个肿瘤疫苗—Gardasil宫颈癌疫苗上市，这种疫苗针对子宫颈癌和尖锐湿疣。美国哥伦比亚广播公司网站列出有关这一新疫苗的十二个问题：
  1、 Gardasil疫苗是什么？Gardasil疫苗是一种针对四种类型的 人乳头瘤病毒(HPV)的疫苗，这四种类型人乳头瘤病毒分别是HPV-6、 HPV-11、 HPV-16和 HPV-18。HPV-16和 HPV-18病毒占全部子宫颈癌发病病因的百分之七十。HPV-6、 HPV-11占全部尖锐湿疣发病病因的百分之九十。批准这种疫苗也是为了帮助预防阴道癌和外阴癌，这两种癌症也是因为HPV病毒引起的。
  2、人乳头瘤
病毒(HPV)是如何传播的？
人乳头瘤病毒(HPV)是通过性途径传播的。人乳头瘤病毒感染很常见。大约有2000万美国人感染了HPV病毒。据疾病预防和控制中心的数据，至少有百分之八十的妇女会在五十岁之前感染这种病毒。多数感染了HPV病毒的妇女不会得子宫颈癌。
  3、Gardasil疫苗是否能预防所有的子宫颈癌？
不能，尽管疫苗可对导致子宫颈癌的主要病毒进行预防，但它对导致子宫颈癌的其它病因没有作用。
  4、 Gardasil疫苗的效果如何？
研究结果表明，对于那些从未感染HPV-16和HPV-18病毒的人来说，防止感染HPV-16 和HPV-18病毒的有效率达100%。
  5、Gardasil疫苗有效期有多长？
实验显示Gardasil疫苗的有效期至少为四年，长期的结果目前还不清楚。
  6、这种疫苗是否包含活性病毒？
不，Gardasil疫苗含有类似病毒的微粒，但并不含有病毒本身。
  7、谁应当注射这种疫苗？
联邦药品和食品局建议9-26岁的妇女注射这种疫苗。联邦药品和食品局的决定并没有使这种疫苗自动成为疾病预防和控制中心的推荐疫苗。制造Gardasil疫苗的公司正在继续为男性儿童和男子研究疫苗，因为他们也可以感染HPV病毒，这可使他们患上尖锐湿疣。
  8、Gardasil疫苗是否安全？
到目前为止的临床疫苗试用报告显示，Gardasil疫苗是安全的。
  9、Gardasil疫苗是否对已感染HPV病毒的妇女有效？
Gardasil疫苗并不是为那些已感染HPV病毒的人士所设计的。
  10、新的疫苗是否使妇女不再需要进行子宫颈癌筛查？
没有，Gardasil疫苗并不能对所有子宫颈癌的病因产生作用，因此进行筛查仍有必要。筛查是发现癌症的关键措施。对于那些没有注射疫苗或者已感染HPV病毒的妇女来说， 筛查仍有必要。
  11、另外三种子宫颈癌疫苗是什么？
Gardasil疫苗是获得批准的首个子宫颈癌疫苗。事实上，它是第一种可以预防癌症风险的疫苗。另一种子宫颈癌疫苗Cervarix也正在研发之中。它预计将于2006年年底提交批准。
  12、每年有多少人患子宫颈癌？有多少人死于子宫颈癌？
美国防癌协会预计，2006年将有9710名例子宫颈癌病例被确诊，3700名美国妇女将因患子宫颈癌而死亡。在全球范围内，子宫颈癌是导致妇女死亡的主要癌症之一。据联邦食品和药品局的数据，每年全球新发47万病例，233000名妇女因患子宫颈癌死亡。

宫颈癌疫苗被批准用于预防外阴和阴道的癌前病变和癌症以及女性尖锐湿疣.在部分国家,该疫苗也被批准用于预防男性的尖锐湿疣.
该四价疫苗于2006年首度获得上市许可.它含有HPV-6,HPV-11,HPV-16和HPV-18的VLPs.该疫苗在酵母培养基中制备,采用非晶形铝的羟基磷酸硫酸盐作为佐剂.每0.5 ml四价疫苗中HPV6/11/16/18型的L1蛋白的含量分别为20μg/40μg/40μg/20μg,这些成分吸附于225 g的佐剂.该疫苗配方不含抗生素,硫柳汞或其他防腐剂.该疫苗被批准在青春期早期的少女中(在某些国家
年龄甚至放宽至9岁)用于预防宫颈癌前病变和宫颈癌以及女性的尖锐湿疣.此外,该四价疫苗也被批准用于预防外阴和阴道的癌前病变和癌症以及女性尖锐湿疣.在部分国家,该疫苗也被批准用于预防男性的尖锐湿疣.

9至26岁男性打宫颈癌疫苗可防尖锐湿疣

FDA于表示，同意将宫颈癌疫苗嘉德西(Gardasil)用于防治男性生殖器疣(又称尖锐湿疣)。专家委员会以7∶0的投票结果认同制药公司所提交的有关嘉德西对于防治9—26岁男性生殖器疣有效的数据。

嘉德西可有效预防人乳头状瘤病毒(HPV)感染，被广泛应用于宫颈癌的防治，经实践表明具有良好的安全性，给广大女性带来的益处远大于其潜在的副作用。而男性生殖器疣也是HPV感染最常见的临床表现。

Gardasil's safety record normal: study

he safety record of Gardasil, a vaccine aimed at protecting girls and young women from cervical cancer, seems to be similar to that of other vaccines, a study of side-effect reports in the U.S. suggests.

The vaccine protects against infections with some strains of the human papillomavirus, or HPV, that are said to be responsible for about 70 per cent of cervical cancers and most genital warts.

The vaccine does not appear to be causing any unusual side-effects, with fewer than one per cent of patients saying they experienced fainting, nausea or dizziness, Dr. Barbara Slade of the U.S. Centers for Disease Control and Prevention and colleagues reported in Wednesday's issue of JAMA.

"For 23 million doses that have been sent out, we've received 12, 424 reports of adverse events," Dr. Barbara Slade of the U.S. Centers for Disease Control and Prevention said in a journal release.

The rates were comparable to those of other vaccines given to girls the same age at 54 reports per 100,000 doses given, the researchers said.

The team found 772 of the adverse events, or 6.2 per cent, were serious, including 32 deaths, as well as reports of anaphylaxis (severe allergic reaction), dangerous blood clots and nerve injury that can cause paralysis.

(Researchers were able to verify 20 of the 32 deaths, with four reports from the manufacturer providing no further information and eight secondhand reports that could not be verified.)

"Most of the [adverse event] rates were not greater than the background rates compared with other vaccines, but there was disproportional reporting of syncope and venous thromboembolic events," the study's authors concluded. Syncope is fainting, while VTEs are a form of embolism, or arterial obstruction.

The safety profile after the vaccine went on the market is "broadly consistent" with safety data from prelicensing trials, they added.

Adverse event reports do not show a vaccine or some other factor caused problems or deaths, only that they occurred after receiving a vaccine. Reactions can occur to the active ingredients in vaccines and the preservatives.

Specifically, for every 100,000 vaccine doses given, there were: 8.2 reports of syncope or fainting. 7.5 reports of local site reactions such as swelling at the injection site 6.8 reports for dizziness 5.0 reports for nausea 4.1 reports for headache. 3.1 for hypersensitivity reactions. 2.6 for urticaria or skin rash. 0.2 for venous thromboembolic events, autoimmune disorders, and Guillain-Barré syndrome, which can cause temporary paralysis. 0.1 anaphylaxis and death. 0.04 for transverse myelitis and pancreatitis. 0.009 for motor neuron disease.

Gardasil's manufacturer, Merck and Co., said it was pleased the study reinforced the safety profile of the vaccine.

"We welcome continued study and discussion about the safety of this important vaccine," Dr. Richard Haupt, pediatrician and head of the clinical program for Gardasil, said in a statement.

Health Canada's adverse drug reaction database includes one adverse reaction involving someone who received Gardasil, among other products, at the time of the reaction. Gardasil was not suspected as the cause of her reaction, and she fully recovered.

Net benefit?
An editorial accompanying the study questioned whether the risk is acceptable for inoculating a healthy population against a disease that can be detected through Pap screens.

The theory behind the vaccine is sound, in that if HPV infection can be prevented then cancer will not occur. But in practice, the issue is more complex, Dr. Charlotte Haug, of The Journal of the Norwegian Medical Association, said in a journal commentary.

The virus does not appear to be very harmful because almost all HPV infections are cleared by the immune system, Haug said. In a few women, infection persists and some women will develop precancerous lesions and eventually cervical cancer later in life.

"The net benefit of the HPV vaccine to a woman is uncertain," Haug wrote.

Personal decision
"Even if persistently infected with HPV, a woman most likely will not develop cancer if she is regularly screened. So rationally she should be willing to accept only a small risk of harmful effects from the vaccine."

A second article appearing in the same issue questioned the marketing of the vaccine, and urged medical groups to be open about ties with pharmaceutical industry. Sheila Rothman and David Rothman of Columbia College of Physicians and Surgeons said Merck provided educational grants to professional medical associations to promote the vaccine.

"When they look through it, there wasn't any big alarm bells, but the story will need to be followed, " said Mark Evans, a family physician in Toronto, noting his family would go ahead and vaccinate their 12-year-old daughter, but that it's a personal decision.

"I wouldn't encourage that you get it, I would encourage you to go in and talk to your doctor or nurse about it."

Fainting is common after vaccines, which is why people are asked to stay at the office for 15 minutes after injections are given, Evans said.

About half of the cases of blood clots were in women with predisposing conditions, and use of the birth control pill can also be a risk factor for clots, he added.

Gardasil is approved by Health Canada for females between the ages of nine and 26. The federal government announced in its March 2007 budget that $300 million over three years will be available to the provinces and territories in support of a national vaccination program. Many school boards have programs to administer the three shots over six months.

Last month, a study in the British Medical Journal also questioned the value of Pap screening for women under 25 because it had no detectable impact on rates of invasive cervical cancer up to age 30. Health Canada's website notes that most women who develop cervical cancer have not been screened in the three years prior to their diagnosis. A more sensitive test that detects DNA from HPV is also being developed.