Cervical Cancer Series 07 Should You Worry About HPV Vaccine Side Effects?
One of the first concerns people have when considering HPV vaccination is the possibility of side effects.
Online, you may come across a wide range of personal stories—from arm pain after vaccination to dizziness, fainting, infertility, and autoimmune diseases. Reading these accounts can make people hesitant about vaccination, even when they know that the HPV vaccine can help prevent cervical cancer and several other cancers.
Like other vaccines and medicines, the HPV vaccine can cause side effects. Some reactions, such as pain or swelling at the injection site, headache, fatigue, and a mild fever, are relatively common. Severe allergic reactions can also occur, although they are very rare and require immediate treatment.
However, not every health problem that occurs after vaccination is caused by the HPV vaccine. Some symptoms may be related to the vaccine, while other illnesses or health problems may simply occur around the same time by coincidence.
For this reason, HPV vaccine safety should be evaluated by looking not only at individual reports but also at large studies comparing vaccinated and unvaccinated populations, along with ongoing safety-monitoring data.
In this article, we will distinguish between reactions that can occur after HPV vaccination and the safety concerns repeatedly raised online.
Are All Symptoms After HPV Vaccination Side Effects?
If you develop a fever or pain after receiving a vaccine, it is natural to assume that the vaccine caused it. Some symptoms that occur soon after vaccination may indeed be related to the immune response or the injection itself.
From a medical perspective, however, a health problem that occurs after vaccination is not necessarily the same as a side effect caused by the vaccine.
Suppose someone is diagnosed with a new condition several days or weeks after receiving an HPV vaccine. It is true that the diagnosis occurred after vaccination, but the timing alone does not prove that the vaccine caused the condition.
HPV vaccines are commonly given to adolescents and young adults. Infections, autoimmune diseases, neurological conditions, and other health problems can occur in this age group regardless of vaccination status.
To determine whether a vaccine is associated with a particular condition, researchers consider questions such as:
Does the condition occur more often than expected among vaccinated people?
Is its incidence higher among vaccinated people than among unvaccinated people?
Are similar findings repeated across different countries and studies?
Is there a medically plausible mechanism through which the vaccine could cause the condition?
Is there a consistent pattern between the timing of vaccination and the onset of symptoms?
It is important to report and investigate health problems that occur after vaccination. However, “it happened after vaccination” and “it was caused by vaccination” do not mean the same thing.
What Are the Most Common Reactions After HPV Vaccination?
The most common reaction after HPV vaccination is pain at the injection site.
The vaccinated arm may feel sore or tender when touched. The skin around the injection site may also become slightly red or swollen. These local reactions can result from the immune response to the vaccine and the injection process itself.
Other possible reactions include:
Headache
Fatigue
Mild fever
Muscle or joint pain
Nausea
Dizziness
A general feeling of being unwell
Most of these reactions are mild and temporary and improve without specific treatment. The type and severity of symptoms can vary from person to person, but the reactions most commonly reported after HPV vaccination are mild and temporary.
You should contact a healthcare professional if pain becomes severe, swelling or redness continues to increase, a fever persists, or the symptoms are serious enough to interfere with daily activities.
Is Dizziness or Fainting After Vaccination a Side Effect?
Dizziness and fainting have also been reported after HPV vaccination. Adolescents and young adults, in particular, may suddenly lose consciousness after receiving an injection.
However, fainting is not considered a reaction unique to a particular ingredient in the HPV vaccine. It is often a vasovagal reaction triggered by fear, anxiety, pain, or the injection process itself. These triggers can temporarily change blood pressure and heart rate.
Symptoms that may occur before vasovagal syncope include:
Sudden dizziness
Cold sweats
Nausea
Pale skin
Blurred or darkening vision
A feeling of weakness
People usually recover quickly from fainting, but they can be injured if they fall and hit their head or another part of the body.
To reduce this risk, vaccination should preferably be given while the person is sitting or lying down. Remaining seated for about 15 minutes after vaccination is also recommended. If you feel dizzy, begin sweating, or notice your vision becoming blurred, tell a healthcare professional immediately rather than trying to endure the symptoms.
Fainting can occur after HPV vaccination, but it is more closely associated with the injection process than with a side effect specific to an HPV vaccine ingredient.
Rare Reactions That Require Immediate Attention
Most reactions to HPV vaccination are mild. However, a severe allergic reaction known as anaphylaxis can occur in very rare cases.
Anaphylaxis is not unique to HPV vaccines. It can also occur in response to other vaccines, medicines, foods, or insect venom. It is a medical emergency that requires prompt treatment.
Seek emergency medical care immediately if any of the following symptoms occur after vaccination:
Difficulty breathing or a feeling that the throat is closing
Swelling of the face, lips, tongue, or throat
Hives that spread rapidly across the body
Sudden and severe dizziness
A rapid heartbeat
Sudden and profound weakness
Confusion, loss of consciousness, or reduced responsiveness
Mild injection-site pain or a low-grade fever should not be confused with these emergency symptoms.
Vaccination providers ask people to remain at the facility for a short period after vaccination so that they can prevent injuries related to fainting and respond quickly to the very rare possibility of an immediate allergic reaction.
Does the HPV Vaccine Cause Infertility?
One of the most common concerns about HPV vaccination is the claim that it may cause infertility or primary ovarian insufficiency.
Primary ovarian insufficiency, previously called premature ovarian failure, generally refers to reduced ovarian function before the age of 40. It can be associated with genetic factors, autoimmune diseases, and certain cancer treatments, although the cause cannot always be identified.
Questions about a possible connection arose after several cases of primary ovarian insufficiency were reported following HPV vaccination. Case reports can help identify health events that occur after vaccination, but they cannot establish that a vaccine caused those events.
To evaluate a possible association, researchers must examine large populations and determine whether primary ovarian insufficiency occurs more often than expected among people who received an HPV vaccine.
A U.S. study involving 199,078 female patients found no increased risk of primary ovarian insufficiency after HPV vaccination. A nationwide Danish study of 996,300 girls and women between the ages of 11 and 34 also found no increase in risk associated with HPV vaccination.
Ongoing safety reviews have found no evidence that HPV vaccination causes primary ovarian insufficiency. Current evidence also does not support claims that HPV vaccination causes infertility.
Medical claims that a risk is absolutely impossible should always be made cautiously. Nevertheless, current large-scale studies do not support the claim that HPV vaccination increases the risk of infertility or primary ovarian insufficiency.
By preventing cervical precancers and cervical cancer, HPV vaccination may also indirectly reduce the potential effects that future treatment for these conditions could have on reproductive health.
Is the HPV Vaccine Associated With Autoimmune or Neurological Conditions?
Online reports have also linked HPV vaccination to autoimmune and neurological conditions.
Conditions that have been discussed in relation to HPV vaccination include:
Postural orthostatic tachycardia syndrome, or POTS
Complex regional pain syndrome, or CRPS
Guillain-Barré syndrome
Bell’s palsy
Other autoimmune diseases
POTS is a condition in which the heart rate rises abnormally when a person stands up, potentially causing dizziness, palpitations, and fatigue. CRPS is a condition involving severe and persistent pain, sensory changes, and other symptoms, usually affecting an arm or leg.
When serious or persistent symptoms develop after vaccination, the person should receive an appropriate medical evaluation. The symptoms should not be dismissed as merely psychological or treated as insignificant.
However, the fact that the symptoms are real and the conclusion that the HPV vaccine caused them are separate matters.
Large studies conducted in Nordic countries and other regions, along with extensive safety reviews, have found no consistent evidence that HPV vaccination increases the overall risk of autoimmune disease.
Reviews by international and national health authorities have found no evidence supporting a causal association between HPV vaccination and POTS or CRPS. Safety monitoring has also not established that HPV vaccination causes Guillain-Barré syndrome or Bell’s palsy.
Possible safety signals have occasionally appeared in individual studies or safety-monitoring systems. However, the same findings were not consistently repeated in larger datasets and follow-up studies, or no meaningful difference was found between vaccinated and unvaccinated populations.
Current large-scale studies and safety reviews have found no consistent evidence that HPV vaccination increases the risk of these conditions.
How Should Reports of Side Effects Online Be Interpreted?
Online, you may see claims that HPV vaccines are dangerous based on the number of adverse events reported after vaccination.
It is important to understand what these reports actually mean.
Spontaneous adverse-event reporting systems do not contain only side effects that have been confirmed as being caused by a vaccine. Patients, caregivers, and healthcare professionals can report health problems that first appeared or were diagnosed after vaccination even when a causal connection has not been established.
This does not mean that the reports are false or have no value. It means that, at the reporting stage, it has not yet been determined whether the vaccine caused the event.
These reporting systems play an important role in identifying rare or unexpected safety concerns quickly. If reports of a particular condition increase above the expected level, health authorities can review medical records, examine other monitoring systems, and use large datasets to investigate whether the risk has actually increased.
Therefore, an adverse-event report is a safety signal that may require further investigation, not proof that the vaccine caused the reported condition.
Individual experiences should not be ignored. At the same time, the number of reports alone should not be used to reach conclusions about vaccine safety.
How Do the WHO and CDC Monitor HPV Vaccine Safety?
Safety evaluation does not end when an HPV vaccine is approved.
Before approval, clinical trials compare symptoms and serious health problems in vaccinated participants with those in comparison groups. However, because clinical trials include a limited number of people, they may not identify every extremely rare adverse event.
Safety monitoring therefore continues after the vaccine is introduced into routine use.
Methods include:
Collecting spontaneous reports of health problems after vaccination
Analyzing medical records and health insurance data
Monitoring whether particular conditions occur more often than expected
Comparing rates of disease among vaccinated and unvaccinated people
Conducting large studies using data from multiple countries
Performing follow-up studies when a possible safety signal is identified
The CDC states that extensive research and findings from multiple safety-monitoring systems continue to support the favorable safety profile of HPV vaccines. The 9-valent HPV vaccine is also continuously evaluated through both pre-licensure clinical trials and post-licensure data from real-world vaccination.
The WHO also regularly reviews safety data and research findings from different countries. When a new suspected event is reported, investigators do not simply count the reports. They examine whether the event occurs more often than expected among vaccinated people, whether its incidence differs from that among unvaccinated people, and whether similar findings appear in other studies.
The purpose of this process is not to declare that a vaccine has no possible risks. It is an ongoing process of weighing the risks identified to date against the vaccine’s cancer-prevention benefits while continuing to monitor for new safety concerns.
When Should HPV Vaccination Be Avoided or Postponed?
Many people can receive an HPV vaccine, but vaccination may not be appropriate immediately in every situation.
A person who experienced a severe allergic reaction, such as anaphylaxis, after a previous HPV vaccine dose should not receive another dose of that vaccine. Vaccination is also contraindicated in anyone who has had a severe allergic reaction to a vaccine component.
Gardasil 9, the 9-valent HPV vaccine used in the United States and many other countries, is produced using yeast. Anyone who has had a severe allergic reaction to yeast or another component of Gardasil 9 should not receive that vaccine and must inform the healthcare professional before vaccination.
People with a moderate or severe acute illness may postpone vaccination until their condition improves. However, a mild cold, minor upper respiratory infection, or mild diarrhea does not necessarily require vaccination to be delayed.
HPV vaccination is not recommended during pregnancy. If someone discovers that they are pregnant after beginning the vaccination series, the remaining doses should be postponed until the pregnancy is over.
However, receiving an HPV vaccine before realizing that you are pregnant is not considered a reason for pregnancy termination or other special intervention. In this situation, inform your healthcare professional and ask for guidance about the remaining doses.
Before vaccination, tell the healthcare professional:
Whether you have previously had a severe allergic reaction to a vaccine
Whether you have a severe allergy to yeast or another vaccine component
Whether you currently have a fever or an acute illness
Whether you are pregnant or may be pregnant
Whether you experienced severe or unexpected symptoms after a previous dose
Giving the healthcare professional accurate information about your allergy history and current health is an important first step toward safe vaccination.
What Should You Do After HPV Vaccination?
After receiving an HPV vaccine, remain seated at the vaccination facility for about 15 minutes, following the provider’s instructions.
Common reactions such as pain or mild swelling at the injection site, a low-grade fever, headache, and fatigue usually improve with time. You can rest and monitor whether the symptoms gradually resolve.
If you feel dizzy, begin sweating, or notice blurred or darkening vision, sit or lie down immediately to prevent a fall. Do not try to walk alone, and inform a healthcare professional right away.
Contact the vaccination provider or another healthcare professional if pain or swelling continues to worsen, a fever persists, symptoms last longer than expected, or you feel too unwell to carry out normal daily activities.
If you develop difficulty breathing, swelling of the face or throat, widespread hives, or reduced consciousness—symptoms that may indicate a severe allergic reaction—do not wait. Seek emergency medical care immediately.
Key Takeaways
The HPV vaccine can cause side effects. The most common reactions are mild and temporary, including pain and swelling at the injection site, headache, fatigue, and a low-grade fever.
Fainting can occur after vaccination, but it is more closely associated with anxiety, pain, or the injection process than with a specific HPV vaccine ingredient. Anaphylaxis is very rare, but suspected symptoms require immediate treatment.
Concerns have also been raised about infertility, primary ovarian insufficiency, autoimmune diseases, and neurological conditions. However, current large-scale studies and safety reviews have found no consistent evidence or confirmed causal relationship showing that HPV vaccination increases the risk of these conditions.
Individual experiences reported online should not be ignored. However, the occurrence of a symptom after vaccination does not by itself establish that the vaccine caused it.
HPV vaccine safety is continuously monitored through large datasets collected not only during pre-licensure clinical trials but also after the vaccine is introduced into routine use.
When deciding whether to receive the vaccine, do not rely solely on individual stories online. Inform your healthcare professional about your allergy history and current health, and consider both the vaccine’s benefits in preventing HPV-related cancers and the side effects and rare risks identified to date.
References
Centers for Disease Control and Prevention. Human Papillomavirus (HPV) Vaccine Safety. Updated March 6, 2025.
https://www.cdc.gov/vaccine-safety/vaccines/hpv.htmlCenters for Disease Control and Prevention. HPV Vaccine Recommendations: Contraindications, Precautions, and Vaccination During Pregnancy. Updated July 9, 2024.
https://www.cdc.gov/hpv/hcp/vaccination-considerations/index.htmlWorld Health Organization. Questions and Answers About Human Papillomavirus (HPV). 2024.
https://iris.who.int/bitstreams/aab05f45-2eb4-4a41-bbec-75c365fab15d/downloadWorld Health Organization. Considerations for Human Papillomavirus (HPV) Vaccine Product Choice. 2024.
https://iris.who.int/server/api/core/bitstreams/0b654f9d-2fd3-4261-94de-f88acb402ae9/contentNaleway AL, Mittendorf KF, Irving SA, et al. Primary Ovarian Insufficiency and Adolescent Vaccination. Pediatrics. 2018;142(3):e20180943.
https://pubmed.ncbi.nlm.nih.gov/30131438/Hviid A, Thorsen NM, Valentiner-Branth P, Frisch M, Mølbak K. Association Between Human Papillomavirus Vaccination and Primary Ovarian Insufficiency in a Nationwide Cohort. JAMA Network Open. 2021;4(8):e2120391.
https://pubmed.ncbi.nlm.nih.gov/34436612/Arnheim-Dahlström L, Pasternak B, Svanström H, Sparén P, Hviid A. Autoimmune, Neurological, and Venous Thromboembolic Adverse Events After Immunisation of Adolescent Girls With Quadrivalent Human Papillomavirus Vaccine in Denmark and Sweden: Cohort Study. BMJ. 2013;347:f5906.
https://pubmed.ncbi.nlm.nih.gov/24108159/European Medicines Agency. HPV Vaccines: EMA Confirms Evidence Does Not Support That They Cause CRPS or POTS. November 20, 2015.
https://www.ema.europa.eu/en/news/hpv-vaccines-ema-confirms-evidence-does-not-support-they-cause-crps-or-pots
Comments
Post a Comment