HPV vaccine: Some studies say one and done might be better

CNN

The World Health Organization will hold its 76th World Health Assembly this week. Nearly 100 countries' health leaders will be joining thousands of others in a global effort to eliminate cervical carcinoma.

According to WHO, cervical cancer is fourth in the list of most common cancers among women. However, many cases can be prevented with the human papillomavirus vaccination.

HPV is an umbrella term for more than 200 viruses. Many do not cause symptoms. Some strains can cause warts and others cancer. The HPV vaccine protects you against most HPV-related diseases.

In his Monday remarks at the World Health Assembly, WHO Director-General Tedros Adhanom Ghebreyesus stated that vaccines bring the dream of eliminating cervix cancer within reach.

Children should be vaccinated because the vaccine works better before anyone has been exposed. HPV is spread by sexual contact. The US Centers for Disease Control and Prevention say that HPV will affect almost everyone who has not been vaccinated.

According to the American Society of Clinical Oncology, the introduction of the vaccine in the US in 2006 along with regular screening has resulted in a significant drop in cases of cervical cancer and deaths. The rates of cervical cancer among the first American generations to be vaccinated has dropped dramatically. According to the American Cancer Society, cervical cancer rates among women aged 20-24 have declined by 65% between 2012 and 2019.

The WHO is pushing for a change in the way doctors administer the HPV vaccine.

The organization has set ambitious goals. WHO hopes that by 2030, 90% of girls in the world will be fully immunized against HPV before they reach the age of 15. WHO reports that coverage is only 13% at the moment.

In the US and most other countries, the vaccine is administered in two or three doses. The CDC recommends vaccination at age 11 or 12 but it can begin as early as 9

The WHO Strategic Advisory Group of Experts on Immunization in 2022 decided that based on current science, one dose would be enough protection. Countries should offer a schedule of one or two shots for girls and young women ages nine to twenty, and a schedule of two doses with a six month interval for older women.

WHO has said that this single-dose approach to cancer prevention could change the game. Logistically speaking, a single dose would be easier to administer than multiple doses and much cheaper. A study shows that people are less likely to receive all the shots they need when they require a series over time.

At least 18 countries, including the UK, Ireland and Australia, have changed their protocols in order to comply with WHO recommendations.

Recent research has shown that a single dose of the vaccine can be highly effective for at least three years. Researchers found that a single dose is as effective as multidose regimens at 24 or 30 month intervals.

The study was not fully published but focused on a double-blind randomized controlled trial, the gold standard in research, to determine if a single shot could protect young healthy women who were vaccinated. It took place at three study locations in Kenya. The study involved 2,275 participants. A third received a vaccine to protect against two HPV-types, another third received a nonavalent vaccination that protected against nine types and the third was given a meningococcal vaccine as a control.

Scientists collected cervical swabs each six months and tested them for HPV DNA. The scientists also examined the effectiveness of each vaccine after three years.

Ruanne Barnabas is the co-principal researcher on the study, as well as the chief of infectious disease at Massachusetts General Hospital. She said that the efficacy of the vaccine remained high at three years and was also durable. These results are a great addition to the evidence that supports the use of one dose of HPV vaccines. They are some of the most effective vaccines we have. We know they work well and that they can prevent cancer. This is another way to reduce cervical cancer.

A similar study published in the journal NEJM last year had similar results.

A Gates Foundation official, who funded the research, stated that in an ideal scenario, two times as many people would be protected if the HPV vaccination was a single-dose vaccine.

Peter Dull who heads the Foundation's efforts to support HPV vaccine research said, "These data really cement confidence in the durability of this protection."

Dr. Kathleen Schmeler is a professor at MD Anderson's Department of Gynecologic Oncology and Reproductive Medicine. She agreed that this study provided'really strong evidence' that a single shot could be effective.

Schmeler said that observational studies conducted in 2014 and 2020 showed that the immunity from a single dose was also lasting.

Some might argue that WHO's decision to only recommend one drug was premature, and that we should wait until years and years' worth of data are available. But, she added, "sometimes the enemy of the good is perfect."

Researchers may find it useful to check back after 10 years to determine if protection has decreased and if people should be revaccinated.

The US is fortunate to have a lot resources. But not everyone has that luxury. Schmeler stated that if you only had to administer one dose it would simplify things and reduce costs.

Dr. Ted Teknos is a specialist in otolaryngology, head and neck surgery at University Hospitals, Cleveland. He is cautious.

He called the results of the study 'encouraging', but wanted to see more long-term effects.

Teknos is a clinical professor at the Department of Otolaryngology of Case Western Reserve University School of Medicine. He was not involved with the research.

Quintin Pan who works on HPV research in University Hospitals Seidman Cancer Center is also reluctant about changing the current protocol. He is concerned that one shot might not be enough to protect against all strains of HPV.

This is also true for HPV. Pan, an Otolaryngology professor at Case Western who was not involved in this study, said that it is also the case for HPV.

Experts say that a one-shot approach to the HPV vaccination could be of great help in many countries. Dull noted that a number of countries still have not introduced the HPV vaccine due to the high cost and difficulties of administering multiple doses.

In many of these regions, it is difficult to give two doses one year apart. This will help countries who want to use the vaccine, but are facing logistical or financial challenges. It is a great way to reduce the barriers for countries.

Teknos expressed his hope that more people – girls, boys, and men – would get the vaccine. The CDC recommends that everyone get vaccinated, but WHO views older women and boys as'secondary' targets who should only be vaccinated if it is affordable and feasible.

The number of boys receiving the vaccine has been falling. In a 2 019 study, it was found that only 4% of boys received the entire course of vaccination, while 15% of girls did.

HPV is not just a cause of cervical cancer. HPV can cause cancer of the throat, anus, penis or vagina as well.

Teknos stated that despite the reduction in cervical cancer rates, the US had seen a massive increase in HPV related head and neck tumors. He said that throat cancers have increased by 300% since 1988. Other HPV-related penile and anal cancers have also increased.

Teknos stated that head and neck cancers caused by HPV are on the rise in the United States.

Dr. Anisha Abraham, Chief of the Division of Adolescent Medicine and Young Adult medicine at Children's National, Washington, also said that she would like to have more long-term information before changing to a new vaccine schedule. She would also like to see more people get the HPV vaccination.

Early vaccination can protect children from HPV-caused cancers and diseases, and could even save their lives. Abraham stated that he thought it was important to start the vaccination series early.