Just in time for Cervical Health Awareness Month, a new study published in the journal JAMA concludes that the HPV vaccine does not increase the risk of multiple sclerosis or any other similar central nervous system conditions.
Human papillomavirus (HPV) is a virus that affects the skin and the moist membranes of the body such as the cervix, anus, mouth, and throat. Although most HPV infections clear without any harmful effects, the virus also causes genital warts and cancers of the cervix, vagina, vulva, anus, penis, and throat.
Two vaccines for the human papillomavirus virus (HPV) exist: Cervarix and Gardasil. Gardasil is a quadrivalent vaccine, protecting against four types of HPV. Cervaris is a bivalent vaccine, protecting against two types of HPV. The Centers for Disease Control and Prevention (CDC) in the United States currently recommends that the HPV vaccine be given as a series of three shots over six months starting at age 9 for both girls and boys.
The most common side effects of the HPV vaccine include minor reactions such as injection site pain, swelling, redness, and headaches. However, case studies had suggested a link between the vaccine and the development of multiple sclerosis and other related diseases. Multiple sclerosis (MS) is an autoimmune disease that affects the brain and spinal cord (central nervous system). Although the disease manifests different from person to person, early symptoms of MS include blurred or double vision, thinking problems, clumsiness or a lack of coordination, loss of balance, numbness, tingling, and weakness in an arm or leg.
Thus, for the present study, researchers in Denmark and Sweden sought to examine whether the quadrivalent HPV (qHPV) vaccination increased the risk of multiple sclerosis and other demyelinating diseases.
Using nationwide registers, the researchers examined the medical records of all Danish and Swedish girls and women between the ages of 10 and 44 between October 2006 and December 2012 (plus another seven months available for the Danish women). The researchers specifically looked at information on qHPV vaccination and diagnoses of multiple sclerosis and other demyelinating diseases.
During the course of the study, 4,322 women developed multiple sclerosis and 3,300 developed other demyelinating diseases related to MS including optic neuritis, neuromyelitis optica, transverse myelitis, and acute disseminated encephalomyelitis. Although the initial numbers appear high, the researchers do note that MS is the most common disabling neurological disease of young adults. Additionally, less than 100 women in each category developed MS or a related condition within the “risk period” or two years following HPV vaccination.
After comparing rates of multiple sclerosis and related diseases among women vaccinated against HPV and unvaccinated women, the researchers did not find an increased risk of developing either multiple sclerosis or any other demyelinating disease among the vaccinated women.
In fact, within the study, multiple sclerosis occurred in 6 of every 100,000 vaccinated individuals per year compared to 21.5 of every 100,000 unvaccinated individuals per year. Other demyelinating diseases occurred in 7.5 of every 100,000 vaccinated indvidiuals per year compared to 16 per 100,000 unvaccinated individuals per year. Despite the lower rates of MS and related diseases among vaccinated individuals, the researchers do caution against linking the HPV vaccine to a decreased risk of developing a demyelinating disease due to a variety of factors including the age of onset of the diseases.
Conclude the study authors on the findings:
“Our study adds to the body of data that support a favorable overall safety profile of the HPV vaccine and expands on this knowledge by providing comprehensive analyses of multiple sclerosis and other demyelinating diseases.”
In December, the Food and Drug Administration (FDA) approved Gardasil 9 (Human Papillomavirus 9-valent Vaccine, Recombinant), which provides protection against five more strains of HPV than the previous Gardasil.
References
Gardasil HPV Vaccine Not Linked To Multiple Sclerosis Or Related Diseases: http://www.forbes.com/sites/tarahaelle/2015/01/06/gardasil-hpv-vaccine-not-linked-to-multiple-sclerosis-or-related-diseases/
HPV Vaccine Is Not Associated With A Greater MS Risk: Study: http://www.medicaldaily.com/hpv-vaccine-not-associated-greater-ms-risk-study-316596
Quadrivalent HPV Vaccination and Risk of Multiple Sclerosis and Other Demyelinating Diseases of the Central Nervous System: http://jama.jamanetwork.com/article.aspx?articleid=2088853
Image Credits
Gardasil HPV Vaccine: http://commons.wikimedia.org/wiki/File:Gardasil_vaccine_and_box.jpg
