HUMAN PAPILLOMA VIRUS, VACCINES AND CONCERNS

HUMAN PAPILLOMA VIRUS Vaccination and Concerns:

Dr.T.V.Rao MD HUMAN PAPILLOMA VIRUS Vaccination and Concerns Dr.T.V.Rao MD 1

Human papillomavirus :

Human papillomavirus (HPV ) is a member of the papillomavirus family of viruses that is capable of infecting humans. Like all papillomaviruses, HPVs establish productive infections only in the stratified epithelium of the skin or mucous membranes. While the majority of the nearly 200 known types of HPV cause no symptoms in most people, some types can cause warts (verrucae), while others can – in a minority of cases – lead to cancers of the cervix, vulva, vagina, and anus in women or cancers of the anus and penis in men. Human papillomavirus Dr.T.V.Rao MD 2

Sexual Contact mainly spread the Infection:

More than 30 to 40 types of HPV are typically transmitted through sexual contact and infect the anogenital region. Some sexually transmitted HPV types may cause genital warts. Persistent infection with "high-risk" HPV types—different from the ones that cause skin warts—may progress to precancerous lesions and invasive cancer . HPV infection is a cause of nearly all cases of cervical cancer however, most infections with these types do not cause disease. Sexual Contact mainly spread the Infection Dr.T.V.Rao MD 3

HPV 16 and 18 are High risk factors :

HPV types 6 and 11 are typically labeled as low risk because infection with these types has low oncogenic potential and usually results in the formation of condylomata and low-grade precancerous lesions. HPV types 16 and 18 have emerged as the high-risk types of HPV because they are responsible for most high-grade intraepithelial lesions that may progress to carcinomas, particularly those in the anogenital and/or mucosal category. HPV 16 and 18 are High risk factors Dr.T.V.Rao MD 4

The percentages of cancers caused by oncogenic HPV are as follow:

Cervical cancer 100% Anal cancer - 90 % Vulvar cancer - 40 % Vaginal cancer - 40 % Oropharyngeal cancer - 12 % Oral cancer – 3% The percentages of cancers caused by oncogenic HPV are as follow Dr.T.V.Rao MD 5

The Incidence Differs in Developing World:

In many lesser-developed countries, cervical cancer is the most common cancer among women because of the lack of effective screening programs that monitor cervical cytology by Pap smear. 3 However, a single round of HPV screening has been demonstrated to be far superior to conventional cytology in reducing the incidence of cervical cancer morbidity and mortality. 4 The Incidence Differs in Developing World Dr.T.V.Rao MD 6

Can Cause Cancers Several Types of Cancers:

HPV infections can persist for many years. Persistent infections with high-risk HPVs are the primary cause of cervical cancer. HPV infections also cause some cancers of the anus, vulva, vagina, penis, and oropharynx Can Cause Cancers Several Types of Cancers Dr.T.V.Rao MD 7

What is the association between HPV infection and cancer?:

Persistent HPV infections are now recognized as the cause of essentially all cervical cancers. It was estimated that, in 2010, about 12,000 women in the United States would be diagnosed with this type of cancer and more than 4,000 would die from it. Cervical cancer is diagnosed in nearly half a million women each year worldwide , claiming a quarter of a million lives annually. What is the association between HPV infection and cancer? Dr.T.V.Rao MD 8

Multiple Sex Partners a Risk Factor:

Having many sexual partners is a risk factor for HPV infection. Nevertheless, most HPV infections go away on their own without causing any type of abnormality. However, even among women who develop abnormal cervical cell changes because of persistent infection with high-risk HPV types, the chances of developing cervical cancer are small, even if the abnormal cells are not treated. Multiple Sex Partners a Risk Factor Dr.T.V.Rao MD 9

Human Papilloma Virus:

Sexually Transmitted Virus which can lead to cervical dysplasia (cancer). Human Papilloma Virus Types {16,18,31,45} account for 75% of cervical cancer Found in 99.7% of all cervical cancers Dr.T.V.Rao MD 10

Human Papilloma Virus:

80% of the sexually active adult population will contract HPV Human Papilloma Virus 2004 U.S. spent over $1.6 billion in treating symptoms of HPV $5-6 billion spent on screening tests such as pap smears. 2005 U.S. estimates 13,000 cases of cervical cancer More than 5,000 will die from cervical cancer Dr.T.V.Rao MD 11

Sexually Active:

The range in years in which an individual changes sexual partners more than once per year on average Sexually Active We define the sexually active population age range as: Dr.T.V.Rao MD 12

Sexually Active Ages:

Given this concept of sexual activity the age ranges for each model are : Sexually Active Ages Age (years) 0 20 40 15 30 HPV 15-30 Dr.T.V.Rao MD 13

Risk of Transmission:

Risk of Transmission The risk of transmission is based on two factors: The average number of sexual encounters with one partner The risk of transmission in one sexual encounter Dr.T.V.Rao MD 14

Pathophysiology of HPV Infection:

Pathophysiology of HPV Infection Laboratory research has indicated that HPVs produce proteins known as E5, E6, and E7. These proteins interfere with the cell functions that normally prevent excessive growth. For example, HPV E6 interferes with the human protein p53, which acts to keep tumors from growing. A better understanding of how these proteins interact may help researchers develop ways to interrupt the process by which HPV infection can lead to the growth of abnormal cells Dr.T.V.Rao MD 15

Relative Risk of Transmission:

: Relative Risk of Transmi ssion HPV Male-to-Female 80% Female-to-Male 70% Dr.T.V.Rao MD 16

How are HPV infections detected?:

Cervical cells can be tested to identify high-risk types of HPV that may be present. HPV DNA tests look for viral DNA from multiple high-risk HPV types and can detect the presence of a viral infection before any cell abnormalities become visible. The FDA has approved HPV DNA tests for follow-up testing of women with equivocal cell abnormalities on a Pap test (a screening test to detect cervical cell changes). HPV DNA tests are also approved for general cervical cancer screening of women over the age of 30 when done together with a Pap test. There are currently no approved tests to detect HPV infections in men. How are HPV infections detected? Dr.T.V.Rao MD 17

FDA Approves Vaccine for HPV:

The U.S. Food and Drug Administration (FDA) has approved two vaccines to prevent HPV infection: Gardasil® and Cervarix®. Both vaccines are highly effective in preventing persistent infections with HPV types 16 and 18 , two high-risk HPVs that cause most (70 percent) cervical cancers. Gardasil also prevents infection with HPV types 6 and 11, which cause virtually all (90 percent) genital warts . In addition, there is some initial evidence that Cervarix provides partial protection against a few other HPV types that can cause cancer, but further evaluation is required before the magnitude and impact of this effect is understood. FDA Approves Vaccine for HPV Dr.T.V.Rao MD 18

Two Vaccines are Licensed for Human Use:

Both Gardasil and Cervarix are based on technology developed in part by National Cancer Institute (NCI) scientists. NCI, a component of the National Institutes of Health, licensed the technology to two pharmaceutical companies—Merck and GSK—to develop HPV vaccines for widespread distribution . Two Vaccines are Licensed for Human Use Dr.T.V.Rao MD 19

Gardasil vaccine:

The Gardasil vaccine, which is produced by Merck & Co., Inc. (Merck), is called a quadrivalent vaccine because it protects against four HPV types: 6, 11, 16, and 18. Gardasil is given through a series of three injections into muscle tissue over a 6-month period. The FDA has approved Gardasil for use in females for the prevention of cervical cancer, and some vulvar and vaginal cancers, caused by HPV types 16 and 18 and for use in males and females for the prevention of genital warts caused by HPV types 6 and 11 . The vaccine is approved for these uses in females and males ages 9 to 26 . Gardasil vaccine Dr.T.V.Rao MD 20

Cervarix Vaccine:

Cervarix is produced by GlaxoSmithKline (GSK). It is called a bivalent vaccine because it targets two HPV types: 16 and 18. This vaccine is also given in three doses over a 6-month period. The FDA has approved Cervarix for use in females ages 10 to 25 for the prevention of cervical cancer caused by HPV types 16 and 18. Cervarix Vaccine Dr.T.V.Rao MD 21

The Vaccines are Effective in Targeted HPV types:

Gardasil and Cervarix are highly effective in preventing infection with the types of HPV they target. Studies have shown that both Gardasil and Cervarix prevent nearly 100 percent of the precancerous cervical cell changes caused by the types of HPV targeted by the vaccine for up to 4 years after vaccination among women who were not infected at the time of vaccination The Vaccines are Effective in Targeted HPV types Dr.T.V.Rao MD 22

HPV is Totally Not Protective ?:

Neither of these HPV vaccines has been proven to provide complete protection against persistent infection with other HPV types, although some initial results suggest that both vaccines might provide partial protection against a few additional HPV types that can cause cervical cancer. HPV is Totally Not Protective ? Dr.T.V.Rao MD 23

Vaccine is Not Totally Protective on all types of HPV :

Overall, therefore, about 30 percent of cervical cancers will not be prevented by these vaccines. Also, in the case of Gardasil, 10 percent of genital warts will not be prevented by the vaccine. Neither vaccine prevents other sexually transmitted diseases, and they do not treat HPV infection or cervical cancer. Vaccine is Not Totally Protective on all types of HPV Dr.T.V.Rao MD 24

A Regular Check up for Detection of Cancer Cervix essential even in Immunized:

Because the vaccines do not protect against all HPV infections that cause cervical cancer, it is important for vaccinated women to continue to undergo cervical cancer screening as recommended for women who have not been vaccinated. A Regular Check up for Detection of Cancer Cervix essential even in Immunized Dr.T.V.Rao MD 25

How long do the vaccines protect against infection?:

The duration of immunity is not yet known. Research is being conducted to find out how long protection will last. Phase III clinical trials have shown that Gardasil and Cervarix can provide protection against HPV16 for 4 years. Smaller studies have suggested that protection is likely to last for longer than 4 years, but it is not known if protection conferred through vaccination will be lifelong How long do the vaccines protect against infection? Dr.T.V.Rao MD 26

Will booster vaccinations be needed?:

Studies are under way to determine whether booster vaccinations (supplementary doses of a vaccine, usually smaller than the initial dose or doses, that are given to maintain immunity) are necessary. Will booster vaccinations be needed? Dr.T.V.Rao MD 27

Who should get these vaccines?:

Both Gardasil and Cervarix are proven to be effective only if given before infection with HPV, so it is recommended that they be given before an individual is sexually active. The FDA's licensing decision includes information about the age and sex for recipients of the vaccine. The FDA approved Gardasil for use in females ages 9 to 26 and approved Cervarix for use in females ages 10 to 25. Who should get these vaccines? Dr.T.V.Rao MD 28

Vaccination in Males:

Data from Merck show high efficacy of Gardasil in males for preventing genital warts associated with HPV6 and HPV11, the two HPV types that cause most genital warts. The FDA approved Gardasil for use in males ages 9 to 26 to prevent genital warts caused by HPV6 and HPV11. Vaccination in Males Dr.T.V.Rao MD 29

HPV:

HPV Note: A constant population is maintained. Every year/update in the model a proportion of the population Enters or ages-in as susceptibles Leaves or ages-out Total Sexually Active Population Recovered Susceptible Infectious Vaccinated Vaccinated Infectious Dr.T.V.Rao MD 30

Concerns on HPV Vaccination:

Reports of adverse events after administration of the human papillomavirus (HPV) vaccine ( Gardasil , Merck) have been making headlines, and questions over the safety of the vaccine have been raised by consumers, parents, healthcare professionals, and others, notes a recent joint statement from the US Centers for Disease Control and Prevention (CDC) and the Food and Drug Administration (FDA). But having analyzed the available data, the agencies offer reassurance. Concerns on HPV Vaccination 31 Dr.T.V.Rao MD

HPV safety is Evaluated:

Gardasil is 1 of the "most heavily studied and intensively monitored vaccines," commented John Iskander, MD, acting director of the Immunization Safety Office at the CDC in Atlanta, Georgia . So far the available data suggest that it is safe, he said in an interview, although he added that "there are no medical products, including vaccines, that are completely safe and effective." HPV safety is Evaluated 32 Dr.T.V.Rao MD

Adverse-Event Reports on Watchdog Web Sites:

The actual reports collected by VAERS have been made available on the Web site of the watchdog organization Judicial Watch, which obtained the records from the FDA under the Freedom of Information Act. A compact disc containing 8864 records was sent by the FDA on June 10, 2008. Adverse-Event Reports on Watchdog Web Sites 33 Dr.T.V.Rao MD

PAP Smear is Still Important for timely Diagnosis of Caner Cervix:

Regardless of whether a woman chooses to be vaccinated or not, the take-home message is to start and continue Pap screening throughout your life ," Dr. Harper PAP Smear is Still Important for timely Diagnosis of Caner Cervix 34 Dr.T.V.Rao MD

Is there a totally Safe and Highly Effective Vaccine:

The question remains unanswered as there is no Vaccine which is totally safe and Highly effective to prevent or cure a Diseases. The facts should be learnt with continuous observation and well communicated Knowledge through various peer reviewed Information Is there a totally Safe and Highly Effective Vaccine 35 Dr.T.V.Rao MD

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