Primary ovarian insufficiency (POI), previously known as premature ovarian failure, is one of those tropes pushed by the anti-vaccine religion – HPV vaccines cause POF. Although there is no robust epidemiological or clinical evidence of a link between the vaccine and primary ovarian insufficiency, the myth persists.
The overall safety of the HPV vaccine has been shown over and over again in multiple huge epidemiological studies published in top-tier, peer-reviewed journals. And in those studies, which include millions of patients, there have been no safety signals regarding primary ovarian insufficiency. Yet, the myth persists.
We’ve got a new large study, published in a top-ranked journal, that, once again, refutes this myth. Let’s take a look.
All about HPV vaccines
Genital and oral human papillomavirus (HPV) infections are the most common sexually transmitted infections (STI) in the USA. HPV is generally transmitted from personal contact during vaginal, anal or oral sex.
It’s important to note that there are more than 150 strains or subtypes of HPV that can infect humans – however, only 40 of these strains are linked to one or more different cancers. Of those 40 strain, most are fairly rare.
Although the early symptoms of HPV infections aren’t serious and many HPV infections resolve themselves without long-term harm, HPV infections are causally linked to many types of cancers in men and women. According to current medical research, here are some of the cancers that are linked to HPV:
In addition, there is some evidence that HPV infections are causally linked to skin and prostate cancers. The link to skin cancer is still preliminary, but there is much stronger evidence that HPV is linked to many prostate cancers.
HPV is believed to cause nearly 5% of all new cancers across the world, making it almost as dangerous as tobacco in that respect. According to the CDC, roughly 79 million Americans are infected with HPV – approximately 14 million Americans contract a new HPV every year. Most individuals don’t even know they have the infection until the onset of cancer. The CDC also states that over 31,500 HPV-related cancers are diagnosed in the USA every year. It may be several times that amount worldwide.
There were two HPV vaccines on the world market before 2014. GSK, also known as GlaxoSmithKline, produced Cervarix, a bivalent (protects against two HPV strains) vaccine. It has been withdrawn from the US market (although available in many other markets), because of the competition from the quadrivalent (immunizes against four different HPV strains) and 9-valent (against nine HPV strains) Gardasil vaccines.
Merck manufactures Gardasil, probably the most popular HPV vaccine in the world. The first version of the vaccine, quadrivalent Gardasil, targets the two HPV genotypes known to cause about 70% of cervical cancer and two other HPV genotypes that cause genital warts. In Europe and other markets, Gardasil is known as Silgard.
The newer Gardasil 9, approved by the FDA in 2014, is a 9-valent vaccine, protecting against HPV Types 6, 11, 16, 18, 31, 33, 45, 52, and 58. It targets the four HPV strains found in the quadrivalent version, along with five additional ones that are linked to cervical and other HPV-related cancers. Both versions of Gardasil are prophylactic, meant to be given to females or males before they become exposed to possible HPV infection through intimate contact.
Gardasil is one of the easiest and best ways to prevent a few dangerous and, to abuse the definition slightly, common cancers that afflict men and women. Without a doubt, the HPV vaccine prevents cancer.
Currently, in the United States, the Advisory Committee on Immunization Practices (ACIP) recommends that preteen girls and boys aged 11 or 12 are vaccinated against HPV. The immunization is also recommended for teenage girls and young women up to the age of 26 who did not receive it when they were younger, and teenage boys and young men up to the age of 21.
Let me sum this all up so that if you come away from this section with nothing else, you get this summary. HPV is a sexually transmitted disease. HPV causes 31,500 cancers a year in the USA alone. The HPV vaccine prevents becoming infected by HPV, which means you are protected from these cancers.
What is primary ovarian insufficiency?
Primary ovarian insufficiency describes a condition when a woman’s ovaries stop working normally before she is 40. Many women naturally have reduced fertility starting at about 40 years old, experiencing irregular menstrual periods as they transition to menopause. Women with POI have those symptoms before the age of 40 – sometimes, these symptoms can begin as early as a teenager.
The cause of most cases of POI is unknown. However, there are known risk factors:
- Family history. Women who have close female relatives with POI are more likely to have it.
- Genes. Some changes to genes and genetic conditions put women at higher risk for POI.
- Certain diseases. Autoimmune diseases and viral infections can increase the risk of primary ovarian insufficiency.
- Cancer treatments. Chemotherapy and radiation therapy may increase the risk of POI.
- Age. Younger women can get POI, but it becomes more common between the ages of 35-40.
POI is fairly rare – about 1% of women have been diagnosed with the condition. There is no known treatment.
Primary ovarian insufficiency unrelated to HPV vaccine
In a paper published in Pediatrics, Allison Naleway et al. identified 199,078 females, aged 11-34 years, who were members of Kaiser Permanente Northwest from August 2006 (when Gardasil was first available to Kaiser Permanente members) through the end of 2014, when the study was ended. The researchers used such a large group of females to maximize the number of primary ovarian insufficiency cases.
The cohort study followed each of these nearly 200,000 female members until they either disenrolled from Kaiser, their 35th birthday (when natural changes in menstrual periods or infertility may start), or the end of the study period, whichever came first. During this study period, 119,078 of the females received the Tdap vaccine (for tetanus, diphtheria, and pertussis), 84,783 received the flu vaccine, 58,871 received the HPV vaccine, and 46,231 received the meningococcal conjugate vaccine for meningococcal disease (see Note 1).
In the population of nearly 59,000 females who received the HPV vaccine, they found one case of an individual who may have had symptoms of POI after receiving the vaccine. If there were a higher risk of primary ovarian insufficiency in the vaccinated group, we would expect numbers as high as the non-HPV vaccine “control” group, which had 45 cases. In fact, the hazard ratio shows that there is a 70% lower risk in the HPV vaccinated group compared to the unvaccinated group (although we probably shouldn’t make a claim that the HPV vaccine lowers the risk of POI).
The authors concluded that there was no “statistically significant elevated risk” of primary ovarian insufficiency after receiving the HPV, Tdap, flu, or meningococcal vaccines. The authors stated that “these findings should lessen concern about POI risk after adolescent vaccination.”
This is a powerful, robust, and high-quality study that shows us that there simply is no risk of primary ovarian insufficiency after the HPV vaccination. That myth, based on anecdotes and anti-vaccine beliefs, not evidence, has been debunked.
Every single negative claim about the HPV vaccine has been refuted by huge uncontroversial studies. But the anti-vaccine zealots love moving the goal posts, so tomorrow they will invent some other easily refuted claim about the vaccine. When will it stop?
Notes
- I don’t write many articles about the meningococcal vaccine, but that doesn’t mean it’s unimportant. Meningococcal infections are dangerous and deadly – 10-15% of individuals who contract the disease will die. And 11-19% of those who survive will have lifetime disabilities like loss of limbs or limb function, deafness, nervous system dysfunctions, and brain damage. It spreads among people in close contact. The vaccine prevents this disease, and it should be one given to any child and teen.
Citations
- Bione S, Toniolo D. X chromosome genes and premature ovarian failure. Semin Reprod Med. 2000;18(1):51-7. Review. PubMed PMID: 11299520.
- Naleway AL, Mittendorf KF, Irving SA, Henninger ML, Crane B, Smith N, Daley MF, Gee J. Primary Ovarian Insufficiency and Adolescent Vaccination. Pediatrics. 2018 Aug 21. pii: e20180943. doi: 10.1542/peds.2018-0943. [Epub ahead of print] PubMed PMID: 30131438.
