2023-05-25 10:02:13
Dubai, United Arab Emirates (CNN) — Health leaders from nearly 100 countries took part in the 76th World Health Assembly of the World Health Organization, with thousands more signing up to a global initiative to end cervical cancer.
Globally, cervical cancer is the fourth most common type of cancer among women, according to the World Health Organization, but many cases can be prevented through the use of the human papillomavirus (HPV) vaccine.
HPV consists of a group of more than 200 related viruses. Many of them cause no symptoms at all. Some strains cause warts and some cause cancer. The HPV vaccine protects against the strains that cause most of the cancers associated with HPV.
“Vaccines make the dream of eliminating cervical cancer a reality,” WHO Director-General Tedros Adhanom Ghebreyesus told the World Health Assembly on Monday.
The vaccine is recommended for children because it works best before someone is exposed to the virus. HPV is often spread through sexual contact.
The US Centers for Disease Control and Control states that every sexually active person who has not been vaccinated will be infected with HPV at some point.
For its part, the American Society of Clinical Oncology indicated that the introduction of the vaccine to the United States in 2006, in conjunction with more regular examinations, led to a significant decrease in cervical cancer cases and deaths in the United States.
Cervical cancer rates among the first generation of Americans to be vaccinated have fallen dramatically. Among women ages 20 to 24, rates of cervical cancer fell 65% between 2012 and 2019, according to the American Cancer Society.
But the option to get vaccinated isn’t available in all of these countries, which is part of the reason the World Health Organization is pushing to change the way doctors give the HPV vaccine.
The World Health Organization hopes that by 2030, 90% of girls around the world will be fully vaccinated against HPV by the time they reach the age of 15. Currently, coverage of these vaccines is only 13%, according to WHO.
Currently, in most countries, including the United States, the vaccine consists of a series of two or three doses. The US Centers for Disease Control and Control (CDC) suggests girls get vaccinated when they are 11 or 12 years old, but the process can start as early as 9 years old.
In 2022, the WHO Strategic Advisory Group of Experts on Immunization decided, based on the latest science, that one dose gives sufficient protection, and countries should offer a schedule of one or two doses for girls and women between the ages of 9 and 20, and two doses With an interval of six months between the first and second for women over 21 years old.
The World Health Organization reports that this single-dose approach could be a game-changer for cancer prevention. Logistically, a single dose is much easier to administer and will be much cheaper than multiple doses. Studies also show that when people need a series of doses over time, they are unlikely to get them all.
A recent study provided further evidence that a single dose of the vaccine is highly effective over three years, if not longer. The researchers found that a single dose had an efficacy of up to 97.5% after a year and a half, comparable to multiple-dose regimens at 24 or 30 months.
The study, which has not been fully published, focused on a randomized, double-blind, controlled trial to see if a single injection would protect vaccinated healthy young women at three study sites in Kenya. 2275 participants participated in it, where a third received a vaccine that protects against two types of human papilloma virus, the second got an unbalanced vaccine that protects against nine types, and the third got a vaccine against meningococcus.
The scientists collected cervical swabs every six months and tested them for HPV DNA. They also looked at the effectiveness of the vaccine in each young woman after three years.
“These findings add to the growing body of evidence to support single-dose use, particularly to facilitate access and coverage of HPV vaccines, which are among our most effective vaccines,” said Dr. “It works well, and we know it prevents cancer. So this is another tool that we can use to reduce cervical cancer.”
Another part of this study, published last year in the journal NEJM, had similar results.
An official from the Gates Foundation, which funded the research, explained that if the HPV vaccine was a single dose, twice as many people could be protected ideally.
“This data really builds confidence about the durability of that protection,” said Peter Doll, who leads the foundation’s work to support HPV vaccine development.
Dr. Kathleen Schmeler, associate professor in the division of gynecological oncology and reproductive medicine at MD Anderson, agreed that the study found “really good evidence” that a single dose would work.
Schmeler, who was not involved in the new research, commented that observational studies between 2014 and 2020 also showed that immunity with a single dose lasts.
It might be useful for researchers to check after a decade to see if protection is declining, and if people need to get vaccinated again.
“The United States has the luxury of having a lot of resources, but this is not available everywhere,” Schimler noted. “If you can only take one dose, it simplifies things a lot and brings the cost down dramatically.”
But Dr. Ted Technos, an ENT, head and neck specialist at University Hospitals in Cleveland, was more cautious.
Teknos, a clinical professor also in the department of otolaryngology at Case Western Reserve University School of Medicine, who was not involved in the research, said the study results are “encouraging,” but he wants to see long-term results.
Dr. Quentin Pan, who works on HPV research at the Seidman University Hospitals Cancer Center, was also reluctant to change the current protocol. His concern is that a single dose may not protect against all strains of HPV.
Experts believe that a single-dose approach to the HPV vaccine could be of great help worldwide. Dole noted that a large number of countries have not even provided a vaccine, in part because of the cost and challenges of implementing multiple doses.
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