In the United States, human papillomavirus (HPV) is the most common sexually transmitted infection, according to the US Centers for Disease Control and Prevention (CDC). These infections are so common, it's thought that almost all men and women will eventually get an infection with some kind of HPV. March 4 is International HPV Awareness Day.
Some of these HPV infections may persist and lead to cancer in both women and men. It's estimated that about 37,000 cases of HPV develop into cancer every year. But there is a vaccine that can prevent these infections. The HPV vaccine, which is known as Gardasil, has been shown to prevent six types of cancer: anal, back of the throat, cervical, vaginal, vulvar, and penile. There is nearly 20 years of research showing that after more than 135 million doses of HPV vaccines were given in the US, the vaccine is safe and effective.
New research reported by the CDC in the Morbidity and Mortality Weekly Report has provided even more evidence that the HPV vaccine is a safe and effective way to prevent cancer. This work determined that from 2008 to 2022, the rate of precancerous lesions in women aged 20 to 24 who had been screened for cervical cancer dropped by 80%.
In women aged 25 to 29, there was also a 37% drop. The vaccine is still effective in older individuals, but the efficacy drops, so this was not unexpected. It shows that making a 'catch up' effort with the HPV vaccine can still help prevent cancer.
The HPV vaccine was approved in 2006 by the US Food and Drug Administration (FDA), and it is recommended that children get the vaccine when they are 11 or 12 years old. (The vaccine has been approved for anyone under the age of 26, so a person can still get it if they missed the shot at that age). While vaccination rates have been increasing overall, only 59% of American kids aged 13 to 17 had been fully vaccinated for HPV in 2020.
Unfortunately, research has also shown that some parents think this vaccine may be unsafe. Research reported in JAMA Network Open in 2021 showed that the proportion of parents who had safety concerns about Gardasil was rising. And now, Robert F. Kennedy, Jr. has been made the new US Health and Human Services Secretary. He has repeatedly attacked the vaccine and has a financial stake in lawsuits against the maker of the vaccine, Merck. (He has claimed that stake would be given to a family member since his appointment as Secretary.) One of Kennedy's sons is a lawyer at the law firm handling the lawsuit.
Kennedy has stated, without evidence, that Gardasil is, "the most dangerous vaccine ever invented."
However, adverse events from the HPV vaccine are rare. These can include pain or swelling at the injection site, dizziness, fainting, nausea, or headache. In extremely unusual cases (about 3 cases for every million doses given), an allergic reaction known as anaphylaxis may occur.
Cancer researcher Jane Montealegre of MD Anderson Cancer Center in Houston told the Associated Press that this latest CDC study, "should reassure parents that they're doing the right thing in getting their children vaccinated against HPV."
Sources: CDC, Medical Express via AP
