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Vaccine Injuries

Explore conditions associated with vaccines and how they are defined.

Anaphylaxis

A severe, potentially life-threatening allergic reaction that can occur shortly after vaccination.

Brachial neuritis

A nerve condition affecting the shoulder and arm, causing sudden pain followed by weakness or loss of muscle control.

Disseminated varicella vaccine-strain viral disease (strain testing not done or inconclusive)

Disseminated varicella vaccine-strain viral disease happens when the weakened chickenpox virus used in the vaccine spreads beyond the area where the shot was given and causes illness. This can include a widespread chickenpox-like rash or disease affecting another part of the body, such as an internal organ. If an organ other than the skin is affected, doctors must show that the virus is actually causing disease in that organ, not just that a lab test is slightly abnormal. If the virus is not found in the affected organ, all symptoms must be part of the same illness occurring at the same time. If testing shows that the illness was caused by the normal (wild-type) chickenpox virus or another virus, it does not qualify as a vaccine-strain viral disease. If testing cannot determine which strain caused the illness, symptoms must begin between 7 and 42 days after vaccination to qualify.

Disseminated varicella vaccine-strain viral disease (vaccine-strain virus identified)

Disseminated varicella vaccine-strain viral disease happens when the weakened chickenpox virus used in the vaccine spreads beyond the area where the shot was given and causes illness. This can include a widespread chickenpox-like rash or disease affecting another part of the body, such as an internal organ. If an organ other than the skin is affected, doctors must show that the virus is actually causing disease in that organ, not just that a lab test is slightly abnormal. If the virus is not found in the affected organ, all symptoms must be part of the same illness occurring at the same time. If testing shows that the illness was caused by the normal (wild-type) chickenpox virus or another virus, it does not qualify as a vaccine-strain viral disease. If testing cannot determine which strain caused the illness, symptoms must begin between 7 and 42 days after vaccination to qualify.

Encephalitis

Inflammation of the brain that can cause fever, seizures, confusion, neurological symptoms, or autism.

Encephalopathy

A serious brain condition involving altered consciousness, confusion, or reduced responsiveness shortly after vaccination.

Guillain-Barre Syndrome

A rare neurological disorder in which the immune system attacks peripheral nerves, causing weakness, tingling, and in severe cases paralysis.

Intussusception

A condition where part of the intestine slides into an adjacent section, which can cause a blockage.

SIRVA

Shoulder Injury Related to Vaccine Administration (SIRVA), typically involving shoulder pain and reduced range of motion after injection.

Thrombocytopenic purpura

Thrombocytopenic purpura is a condition in which the body has an unusually low number of platelets, the blood cells that help stop bleeding. People with this condition may bruise easily, develop tiny red or purple spots on the skin (called petechiae), or experience bleeding from the nose, gums, or other moist tissues.

Varicella vaccine-strain viral reactivation disease

Varicella vaccine-strain viral reactivation disease happens when the weakened chickenpox virus used in the vaccine becomes active again later in life and causes shingles. Shingles is a painful, itchy rash that usually appears on one side of the body and follows the path of a nerve. In some cases, the virus can affect parts of the body other than the skin. If that happens, doctors must show that the virus is actually causing disease in that organ, not just that a lab test is slightly abnormal. To qualify, laboratory testing must confirm that the illness was caused by the vaccine strain of the chickenpox virus. Tests such as PCR can be used to identify the virus. If testing shows that the illness was caused by the normal (wild-type) chickenpox virus or by another virus, it is not considered a vaccine-strain viral reactivation disease.

Vasovagal syncope

A brief fainting episode caused by a drop in heart rate and blood pressure, often triggered by stress or pain around vaccination.