Screening for Vaccine Reactions

10 Risk Factors Every Parent Should Know

Concerns about the risk of vaccine reactions are what lead some parents to needlessly skip or delay some of their children's recommended vaccines. Doing so doesn't reduce the risk of harm; rather, it places a child at a high risk of getting a potentially serious vaccine-preventable disease.

Nurse giving child a vaccine

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This is not to suggest that all vaccines are safe for all children. While the benefits of vaccination invariably outweigh the risks, there are certain conditions that can increase the risk of adverse reactions and may even contraindicate the use of a vaccine in some kids.

There is a plethora of myths and misinformation about vaccines circulating on social media. The information on risk factors for vaccine reactions presented here is backed by authoritative sources and can help you sort fact from fiction so you make informed decisions about vaccinating your child.

Risk Factors for Vaccine Reactions

Having a risk factor for an adverse vaccine reaction does not mean your child will necessarily experience one. It just means that their personal risk will need to be assessed by an experienced pediatrician or immunologist.

In some cases, a vaccine may be outright contraindicated for use. In others, a vaccine may be used with caution.

Risk factors for vaccine reactions include:

  • History of allergies: If your child has a history of severe allergic reactions to latex, yeast, gelatin, eggs, neomycin, polymyxin B, or streptomycin, advise your healthcare provider beforehand. Although the risk of a severe allergic reaction to a vaccine is extremely rare, the child would need to be monitored afterward to ensure there are no signs of a dangerous, whole-body allergic reaction known as anaphylaxis.
  • Prior vaccine reactions: Generally speaking, if your child has had a reaction to a particular vaccine in the past, that vaccine should not be given again. This includes an allergic reaction (which involves antibodies called immunoglobulin E) or a hypersensitive reaction (which does not).
  • Recent vaccination: Some vaccines can be given together; others cannot. If your child is due for a live vaccine, they should not get another live vaccine within four weeks.
  • Current illness: Symptoms of a mild illness (such as mild diarrhea, low-grade fever, nasal congestion, cough, or mild ear infection) are usually not a reason to delay a vaccine even if antibiotics are used. On the other hand, a severe illness often is.
  • Pre-existing conditions: Children with asthma, lung disease, heart disease, kidney disease, diabetes, or asplenia (the absence of a spleen) should never get the live nasal spray flu vaccine (FluMist); a flu shot should be administered instead. A host of other vaccines may also be contraindicated, particularly in people with liver disease, kidney disease, or asplenia.
  • Immunodeficiency: Children whose immune systems are compromised (including those with cancer, HIV, or primary immunodeficiency, as well as organ transplant recipients) are generally advised to avoid live vaccines.
  • Immunosuppressive therapy: Children prescribed immunosuppressant drugs like high-dose cortisone, prednisone, or chemotherapy are typically advised to avoid live vaccines until their immune system has recovered. The same applies to children who have undergone radiation therapy. Short-course immunosuppressants (such as a cortisone shot used to treat a joint injury) pose few concerns, however.
  • Blood transfusion: Children who have received a transfusion of blood or blood products, or have been given immunoglobulins from human plasma, also need to avoid live vaccines for a period of time. If a transfusion is needed, the live vaccine should be given at least two weeks before the transfusion or three to 11 months after it, depending on the vaccine.
  • Neurological disorders: If your child had a recent seizure, coma, or other severe neurological symptoms, the DTaP vaccine would likely be deferred until the child's condition has stabilized. Children with stable neurological disorders, such as cerebral palsy or epilepsy, can usually get the DTaP shot safely.
  • Pregnancy: If your teen is pregnant, she should not receive a live virus vaccine, especially during the first trimester. Live vaccines pose a theoretical risk of harm to the fetus and are generally avoided as a precautionary measure.

Vaccines Doctor Discussion Guide

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When Adverse Events Occur

While anti-vaccination proponents ("anti-vaxxers") often claim that vaccines cause everything from autism, sudden infant death syndrome (SIDS), and multiple sclerosis to Crohn's disease, type 1 diabetes, and asthma, there has yet to be any credible evidence to support these claims.

Oftentimes, coincidental events get blamed on vaccines, and these reports are later spun as "proof" of a vaccine's harm.

The truth is, true vaccine injuries are extremely rare.

If an adverse event occurs soon after a vaccination, it is important to get it evaluated and not assume that the vaccine is the cause. These may include things like a skin reaction, fever, or dizziness that may or may not have anything to do with the vaccine.

Some pediatricians use what is called a Clinical Immunization Safety Assessment (CISA) algorithm tool to help determine if the reaction is consistent with the vaccine.

To assess the likely cause, the healthcare provider needs to know:

  • Which vaccine was received
  • All of the symptoms your child developed
  • When the symptoms occurred in relation to the vaccination
  • What other things your child may have been doing or exposed to prior to the onset of symptoms
  • Your child's pre-existing health condition(s), if any
  • If your child ever had any previous reaction to a vaccine or drug

Among other things, the algorithm can help determine if an allergic reaction is vaccine-related and if further skin testing is needed to pinpoint the allergen (such as egg protein or latex).

If a vaccine is found to pose a serious health risk, you can seek a medical exemption for your child's school or to show local customs and immigration officials when traveling abroad.

According to a 2016 study published in the Journal of Allergy and Clinical Immunology, there were only 33 cases of a severe anaphylactic reaction out of 25,173,965 doses of childhood vaccines delivered to American schoolkids between January 2009 and December 2011.

If your healthcare provider is not sure if a reaction is vaccine-related, they can request a (CISA) consultation with an expert at the Centers for Disease Control and Prevention (CDC) by calling 800-CDC-INFO (800-232-4636).

Reporting and Compensation

If you think that your child has had a vaccine injury, ask your pediatrician to lodge an incident report with the Vaccine Adverse Event Reporting System (VAERS).

If a vaccine is confirmed to be the cause of an injury, you can seek compensation from the National Vaccine Injury Compensation Program (VICP). This federal "no-fault" system compensates for medical and legal expenses, loss of future earnings, up to $250,000 for pain and suffering, and up to $250,000 if death occurred due to administration of a vaccine covered by VICP.

Compensation is only available to U.S. citizens and if the claim is made within three years of the reported incident.

A Word From Verywell

It is reasonable to have pangs of anxiety about vaccinations; nobody enjoys getting shots. But the overwhelming body of evidence has shown the benefits of vaccines outweigh the risks. Not only does vaccination reduce the risk of illness on an individual basis, but it also reduces the spread of infection within a community.

If you have any of the risk factors for an adverse vaccine reaction, speak with your healthcare provider. In most cases, the likelihood of a reaction will be low. Even so, by advising your practitioner or clinic in advance, they can monitor for any concerning signs or symptoms and be prepared to respond if needed.

9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Chung EH. Vaccine allergies. Clin Exp Vaccine Res. 2014 Jan;3(1):50-7. doi:10.7774/cevr.2014.3.1.50

  2. Centers for Disease Control and Prevention. Preventing and managing adverse reactions: general best practice guidelines for immunization: best practices guidance of the Advisory Committee on Immunization Practices (ACIP).

  3. Centers for Disease Control and Prevention. Vaccines when your child is sick.

  4. Department of Health & Human Services. Vaccines for people with health conditions.

  5. Zabeida A, Lebel MH, Renaud C, Cloutier M, Robitaille N. Reevaluating immunization delays after red blood cell transfusion. Transfusion. 2019 Sep;59(9):2806-11. doi:10.1111/trf.15433

  6. Centers for Disease Control and Prevention. Diphtheria, tetanus, and pertussis vaccines.

  7. Centers for Disease Control and Prevention. Guidelines for vaccinating pregnant women.

  8. McNeil MM, Weintraub ES, Duffy J, et al. Risk of anaphylaxis after vaccination in children and adults. J Allergy Clin Immunol. 2016 Mar;137(3):868-78. doi:10.1016/j.jaci.2015.07.048

  9. Health Resources and Services Administration. What you need to know about the National Vaccine Injury Compensation Program (VICP).

By Vincent Iannelli, MD
 Vincent Iannelli, MD, is a board-certified pediatrician and fellow of the American Academy of Pediatrics. Dr. Iannelli has cared for children for more than 20 years.