HPV Vaccines

Human Papillomavirus (HPV) Vaccines

Vaccination against human papillomavirus (HPV) is recommended to prevent new HPV infections and HPV-associated diseases, including some cancers. 

There are safe and effective HPV vaccines that can protect males and females against diseases, including cancers, caused by HPV. Data were considered from 11 clinical trials of 9vHPV, 4vHPV, and/or 2vHPV in adults aged 27 through 45 years, along with supplemental bridging immunogenicity data, says the US Centers for Disease Control and Prevention (CDC).

HPV Vaccines

Gardasil - Merck's Gardasil vaccine consists of 4 proteins of HPV types 6, 11, 16, and 18. Gardasil is highly efficacious in preventing infection from virus types 16 and 18, which are together responsible for approximately 70% of cervical cancer cases globally. The quadrivalent vaccine is also highly efficacious in preventing anogenital warts, a common genital disease that is virtually always caused by infection with HPV types 6 and 11.

Gardasil 9 - Gardasil 9 consists of HPV proteins, Types 6, 11, 16, 18, 31, 33, 45, 52, and 58. HPV infections can lead to certain cervical cancers. Many females with cervical cancer were probably exposed to cancer-causing HPV types in their teens and early 20s. Additionally, males can get HPV, causing anal and throat cancers, and genital warts.

Cecolin - Innovax's Cecolin HPV Vaccine protects women against HPV 16 and 18, two HPV types causing 70 percent of all cervical cancers, the third most common cancer among women. Starting May 18, 2020, the HPV vaccine developed by Chinese researchers is available in provincial Maternity and Child Healthcare Hospital in Wuhan.

Cervarix - GlaxoSmithKline's Cervarix is a non-infectious recombinant, AS04-adjuvanted vaccine, that contains recombinant L1 protein, the major antigenic protein of the capsid, of oncogenic HPV types 16 and 18.  This HPV vaccine was pulled from the US market in 10/2016.

HPV Vaccine Candidates

TG4001 - TG4001, previously known as Tipapkinogen Sovacivec, is Transgene's vaccine candidate using an attenuated and modified poxvirus (MVA) as a vector expressing the HPV16 E6 and E7 proteins (rendered non-oncogenic) and interleukin-2. 

VGX-3100 - Inovio's investigational immunotherapy vaccine includes DNA plasmids targeting the E6 and E7 proteins of HPV types 16 and 18. Inovio announced positive interim results from an open-label, Phase 2 study showing its lead DNA medicine candidate VGX-3100 to be safe and effective in treating men and women with anal dysplasia, also known as high grade squamous intraepithelial lesion (HSIL), a precancerous condition caused by high-risk HPV types 16/18.

HPV Overview

The CDC recommends individuals should receive the full HPV vaccine series, regardless of age group,

The CDC recommends that 11- to 12-year-olds receive two doses of HPV vaccine at least six months apart, rather than the previously recommended three doses to protect against cancers caused by HPV infections.

Teens and young adults who start the series later, at ages 15 through 26 years, will continue to need three doses of HPV vaccine to protect against cancer-causing HPV infection. Young women can get HPV vaccine through age 26, and young men can get vaccinated through age 21.

HPV vaccination is also recommended for men and women with compromised immune systems (including people living with HIV/AIDS) through age 26 if they did not get fully vaccinated when they were younger.

The U.S. FDA approved an expanded indication for GARDASIL9 for the prevention of oropharyngeal cancers caused by HPV types 16, 18, 31, 33, 45, 52, and 58 on June 13, 2020. 

The oropharyngeal and head and neck cancer indication is approved under accelerated approval based on effectiveness in preventing HPV-related anogenital disease.

HPV is a group of more than 150 related viruses. Each HPV virus in this large group is given a number which is called its HPV type. HPV is named for warts (papillomas) some HPV types can cause.

Some other HPV types can lead to cancer, especially cervical cancer. There are more than 40 HPV types that can infect the genital areas of males and females. But there are vaccines that can prevent infection with the most common types of HPV.

HPV is transmitted through intimate skin-to-skin contact. You can get HPV by having vaginal, anal, or oral sex with someone who has the virus. It is most commonly spread during vaginal or anal sex.

HPV is the most common sexually transmitted infection (STI). Anyone who is sexually active can get HPV, even if you have had sex with only one person.

HPV is so common that nearly all sexually active men and women get it at some point in their lives. HPV can be passed even when an infected person has no signs or symptoms. You can develop symptoms years after you have sex with someone who is infected, making it hard to know when you first became infected.

HPV Symptoms

In most cases, HPV goes away on its own and does not cause any health problems. But when HPV does not go away, it can cause health problems like genital warts and cancer, says the CDC.

Genital warts usually appear as small bumps or groups of bumps in the genital area. They can be small or large, raised or flat, or shaped like a cauliflower. A healthcare provider can usually diagnose warts by looking at the genital area.

Cervical cancer usually does not have symptoms until it is quite advanced, very serious, and hard to treat. For this reason, it is important for women to get regular screening for cervical cancer. Screening tests can find early signs of disease so that problems can be treated early before they ever turn into cancer.

Other HPV-related cancers might not have signs or symptoms until they are advanced and hard to treat. These include cancers of the vulva, vagina, penis, anus, and oropharynx (cancers of the back of the throat, including the base of the tongue and tonsils).

Cancer often takes years, even decades, to develop after a person gets HPV. The types of HPV that can cause genital warts are not the same as the types of HPV that can cause cancers.

There is no way to know which people who have HPV will develop cancer or other health problems. People with weak immune systems (including individuals with HIV/AIDS) may be less able to fight off HPV and more likely to develop health problems from it.

HPV Diagnosis

There is no test to find out a person’s “HPV status.” Also, there is no approved HPV test to find HPV in the mouth or throat.

There are HPV tests that can be used to screen for cervical cancer. These tests are recommended for screening only in women aged 30 years and older. They are not recommended to screen men, adolescents, or women under the age of 30 years.

Most people with HPV do not know they are infected and never develop symptoms or health problems from it. Some people find out they have HPV when they get genital warts. Women may find out they have HPV when they get an abnormal Pap test result (during cervical cancer screening).

Others may only find out once they’ve developed more serious problems from HPV, such as cancers.

HPV Impact

Approximately 33,700 cancers are caused by HPV in the United States each year, including 12,900 oropharyngeal cancers among men and women, 10,800 cervical cancers among women, and 6,000 anal cancers among men and women; vaginal, vulvar, and penile cancers are less common.

HPV vaccination for adolescents has been routinely recommended for females since 2006 and for males since 2011, says the CDC.

The existing HPV vaccination program for adolescents has the potential to prevent the majority of these cancers. Mean age at acquisition of causal HPV infection for cancers is unknown, but is estimated to be decades before cancer is diagnosed.

In 2017, coverage with ≥1 dose of HPV vaccine was 65.5% among adolescents aged 13 through 17 years. Although coverage with the recommended number of doses remains below the Healthy People 2020 target of 80% for adolescents, the U.S. HPV vaccination program has resulted in significant declines in the prevalence of vaccine-type HPV infections, anogenital warts, and cervical precancers.

For example, the prevalence of 4vHPV vaccine-type infection during 2013–2016, compared with those of the prevaccine era, declined from 11.5% to 1.8% among females aged 14 through 19 years and from 18.5% to 5.3% among females aged 20 through 24 years.

In addition, declines have been observed among unvaccinated persons, suggesting protective herd effects, says the CDC.

CONTENT SOURCE:  World Health Organization, US Centers for Disease Control and Prevention, FDA, research studies, manufacturer announcements, and the Precision Vac news network.