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Encephalitis is inflammation of the brain. Encephalitis can cause flu-like symptoms, such as fever or severe headache. It can also cause confusion, seizures, or problems with senses or movement. However, many cases of encephalitis result in mild flu-like symptoms or even no symptoms.

Encephalitis is the medical term used to describe inflammation of the brain.  Encephalitis can be caused by a number of pathogens, including mumps and measles. When a pathogen directly infects the brain and causes inflammation, it is called primary encephalitis.  When inflammation in the brain results from an overactive immune system, it is called secondary encephalitis.  Most cases of vaccine-related encephalitis fall into this second category.  In some people, a vaccine may cause the immune system to turn against the body’s own tissues, resulting in brain inflammation. Encephalitis in children has been associated in rare cases with the development of autistic symptoms.  If certain timing conditions are met, encephalitis is considered a table injury for MMR and DTaP vaccines.

Symptoms of encephalitis include:

  • Headache

  • Fever

  • Muscle aches and weakness

  • Fatigue and weakness

  • Confusion or hallucinations

  • Seizures

  • Loss of feeling or paralysis

  • Difficulty speaking or hearing

  • Loss of consciousness

Seek medical attention if you or a loved one experience any of the symptoms listed above following the administration of a vaccine, and give us a call to help you evaluate whether you can be compensated for a vaccine injury. 


  • Diphtheria, Tetanus, acellular Pertussis (“DTaP”) Vaccine

  • Hepatitis A (“Hep A”) Vaccine

  • Hepatitis B (“Hep B”) Vaccine

  • Human Papillomavirus (“HPV”) Vaccine

  • Influenza (“Flu”) Vaccine

  • Measles, Mumps and Rubella (“MMR”) Vaccine

  • Meningococcal Vaccine

  • Polio (“IPV”) Vaccine

  • Tetanus, Diphtheria, Acellular Pertussis (“Tdap”) Vaccine

  • Varicella (“Chickenpox”) Vaccine

Vaccines save millions of lives each year and protect against the development of, and natural infection with, harmful diseases, such as chickenpox, meningococcus, pneumococcus, and measles, mumps, and rubella (MMR). However, while anti-vaccine folks insist that vaccines cause neurological diseases, like meningitis and encephalitis, the truth of the matter is that the benefit of vaccination in preventing such diseases greatly outweighs the very minimal risk of vaccine complications.

While the varicella (“chickenpox”) and MMR vaccines in routine use in the United States can very rarely cause viral meningitis and measles inclusion body encephalitis (MIBE), respectively, natural infections can and do cause encephalitis and meningitis. Thus, the vaccines for MMR and chickenpox protect against encephalitis and meningitis caused by natural agents. The vaccines are made from attenuated versions of the natural/wild-type viruses, and generally do not cause central nervous system infections in normal hosts. Persons with certain immune deficiencies, however, can suffer from certain neurological diseases as a result of the attenuated vaccine viruses, and is therefore contraindicated in those populations.

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