s right shoulder forty eight hours later the wheal reaction at the vaccination had attained a diameter of eight centimeters two weeks after the second vaccination the patient 39 s headache had disappeared his facial and left tongue swelling were dramatically diminished and the enlarged cervical lymph node had reduced in size for the first time since his admission the patient 39 s weight had increased by 4 0 kg four weeks post vaccination the boy was considered clinically cured one year after the first vaccination a mri performed 6 weeks after the first vaccination showed a decrease in the thickening of the soft tissue and less soft tissue enhancement of the left side of his tongue a mra of the neck released significant improvement of the stenosis of the proximal left internal carotid artery the mri and mra twelve months post vaccination showed no infiltrations in the soft tissue and a normal left internal carotid artery a serum sample collected during the initial weeks post admission gave a negative results in an id for pythiosis although the id test in equine pythiosis is a reliable test some negative results have been reported in humans and dogs with proven pythiosis chetchotisakd p et al j med assoc thailand 75 248 254 1992 and wanachiwanawin w et al trans royal soc trop med hyg 87 296 298 1993 when this serum was tested before vaccination in a new pythium insidiosum elisa positive titers of 1 6 400 were recorded to monitor the vaccination 39 s.