Client found deceased approximately 53 hours after administration of vaccine.  She had no fevers or other apparent systemic effects.  She had congenital developmental delay, epilepsy, spastic quadriplegia, dysphagia, thyroid cancer. This report is submitted for the unexpected death of a patient 2 days later receiving 2006 Influenza vaccination.  Client  was a 43-year-old female with profound mental retardation and severe developmental disability from unknown prenatal factors.  She had been a resident of a residential long term care facility since she was age 2 years.  She was born at full term after an uncomplicated pregnancy except for very little fetal movement.  She had an uncomplicated delivery, breathed spontaneously, weighted 8 pounds, 7 ounces but demonstrated poor tone and flaccidity during the neonatal period with no improvement.  She subsequently demonstrated further profound developmental disabilities, a generalized tonic/clonic seizure disorder, spastic quadriplegia, severe lumbar scoliosis, osteoporosis, osteoarthritis, dysmenorrhea, dysphagia and episodes of aspiration pneumonitis.  She had been diagnosed with a thyroid tumor in 2005, most consistent with thyroid carcinoma but her guardians had elected to not submit her for treatment of this condition.  She had a diffuse, chronic pain syndrome, possibly related to neuromuscular disorders.  She was legally blind and non-verbal.  She was NPO and had a G-tube for all nutrition and medications.  She was severely disabled, dependent on others for all ADL and had no effective means of communication.  She had an Advance Directive and a DNR order.  Her guardians are her parents.  Client had been in a general decline in health for several years and was being treated for her acute and chronic conditions but with an emphasis on comfort measures and measures to maximize her quality of life.  She received influenza vaccinations annually due to being a high risk individual resident of a long term care facility with no recorded adverse reactions.  On 10-17-06 she had a routine medical evaluation and was found to be in her usual state of compromised health, with no change in treatment recommended.  She was given an influenza vaccine on 10-21-06 at her residence by a facility nurse and appeared to be in stable health at that time.  On daily follow up by nursing she did not appear to be in ill health or have any adverse reaction to the vaccine, with no fever, apparent pain or other discomfort, no abnormal vital signs or rash.  She was last observed during a bed check by her residential staff at 3:30 am on 10-24-06, about 53 hours after the vaccination was given and was observed to be sleeping comfortably in prone position and in no distress.  The staff neither heard nor witnessed anything unusual but when they checked her one hour later at 4:30 am she was found to be unresponsive, cyanotic, with no respiratory effort and no pulse.  Since she had a legal DNR in effect no resuscitation effort was made.  She was pronounced dead at 4:50 am on 10-24-2006 by doctor name given.  The Coroner was contacted, the death was determined to be of natural causes and the body was released to Mortuary. 11/13/06 Received Death Certificate which revealed COD as cardiopulmonary arrest; generalized tonic/clonic seizure disorder; with contributing factors of congenital developmental disability.