hypersensitivity reaction , hypotensive  hyporesponsive shock and postvaccination encephalopathy are the most dreaded complications associated with diphtheria , pertussis ( whooping cough ) , and tetanus ( dpt ) vaccine . occurrence of postvaccination encephalopathy and hypotensive  hyporesponsive shock is a contraindication of further doses of the pertussis component . manifestations that indicate occurrence of encephalopathy include the following : seizures with or without fever occurring within 3 days of immunization and persistent , severe , inconsolable screaming , or crying for 3 or more hours within 48 h of immunization . neurological complications are thought to be primary due to the pertussis component of the vaccine and the estimated risk is 1 per 1,70,000 doses administered . here , we report a case of dpt - induced recurrent seizures and acute encephalopathy in a child possibly due to pertussis fraction . a 5-month - old male patient weighing 6.78 kg was admitted with a complaint of generalized tonic clonic seizure for 45 times per day for 5 days in pediatric ward of sir takhtsinhji general hospital , bhavnagar , gujarat . after 3 days of vaccination , the child developed seizures and admitted to the nearby community health center ( chc ) for 9 days . the patient was discharged after the control of seizures and was at home for 3 days without any treatment . after that the patient was admitted and treated with phenytoin , methyl prednisolone , and levetiracetam in private hospital at bhavnagar . afterward the patient was transferred to our center for further management . there was no history of head injury , trauma , tuberculosis , febrile convulsion , and ear discharge . investigations , such as total leukocyte count , differential leukocyte count , red blood cell ( rbc ) count , packed cell volume , rbc indices , platelet count , erythrocyte sedimentation rate , peripheral smear examination , random blood sugar , liver function tests , renal function tests , and cerebrospinal fluid examination were normal except hemoglobin ( 10.5 g / dl ; reference value : 12.018.0 g / dl ) , ldh ( 439 iu / l ) , and ionized calcium ( 1.06 mmol / l ; reference value : 1.161.32 mmol / l ) . the patient was treated with midazolam , phenytoin , levetiracetam , phenobarbitone , and clobazam . after omitting clobazam , acyclovir and methyl prednisolone were started as empirical therapy on the 2nd day of admission . from 7th day naranjo 's scale showed that the relationship between dpt and acute encephalopathy was probable . according to brighton criteria for vaccine - induced encephalopathy , the present adverse event was of level 3 . according to modified schumock and thornton 's criteria , this reaction was definitely preventable and modified hartwig and siegel 's scale showed that the reaction was moderately severe . evaluation of vaccination programs requires continuous monitoring of the vaccination coverage , equity of access , incidence and severity of the diseases targeted in the program and also the safety of the vaccination . adverse event following immunization ( aefi ) is defined as a medical incident that takes place after an immunization , causes concern , and is believed to be caused by the immunization . it is important to note that the benefits of protection afforded by a vaccine always far exceed the small risk of a serious and life - threatening reactions . a few cases of dpt - induced serious neurologic adverse effects were reported from india . it causes neurologic damage : by affecting cellular signaling , catecholaminergic and gabaergic systems and defect in blood whole cell pertussis vaccine induces the il-1 production in the hippocampus and hypothalamus of vaccinated animals . this leads to decrease in release of the inhibitory neurotransmitters gaba and adenosine in the hippocampus and induce convulsive activity . association of such severe reactions made the whole - cell pertussis vaccine highly unpopular and withdrawal of it from many countries . occurrence of neurologic complications is a contraindication for subsequent doses of the whole - cell dpt vaccine and its replacement by the acellular type . whole - cell pertussis vaccines contain 3000 different proteins , whereas acellular pertussis vaccine ( dtap ) contains 25 proteins . this may be the reason for less chances of seizures , encephalopathy , and hypotensive episodes with dtap as compared to whole - cell vaccine . an acellular pertussis vaccine ( designated as ap ) is now available in several countries , including india . the price of dpt vaccine ( triple antigen of glaxosmithkline ) and dtap vaccine ( boostrix of glaxosmithkline ) are rs . 3 and rs . 699 per dose , respectively . the higher cost may be the reason for inclusion of dpt vaccine instead of dtap vaccine in indian national immunization schedule . according to who , local and nonserious systemic reactogenicity are more commonly associated with whole - cell pertussis containing vaccines . however , acellular pertussis containing vaccines are unlikely to be currently affordable in most developing countries and there is insufficient marginal benefit to consider changing from whole - cell pertussis - containing vaccine to acellular pertussis - containing vaccine . by 2009 , 1 of the 49 least developed countries and 13 of 88 developing countries have adopted acellular pertussis vaccine into their national immunization programs . indian academy of pediatrics ( iap ) also endorses the continued use of whole - cell pertussis vaccine . it is suggested that dtap vaccine can be preferred over dpt vaccine for those who can afford it . this case highlights the importance of the continuous monitoring of vaccine - related adverse events of whole - cell dpt vaccine in countries where it is preferred because of the economic reason .
a 5-month - old male patient developed recurrent seizures and acute encephalopathy possibly due to first dose of diphtheria , pertussis ( whooping cough ) , and tetanus ( dpt ) vaccine used for routine immunization . 
 postreaction computed tomography ( ct ) scan of brain , magnetic resonance imaging ( mri ) of brain , and electroencephalogram were normal . 
 pertussis fraction of dpt vaccine is responsible for this reaction . 
 it is suggested that acellular pertussis vaccine should be used instead of whole cell vaccine because it is associated with lower frequency of neurological complications , such as seizures , encephalopathy , and hypotensive episodes 
 . however , acellular pertussis - containing vaccines are currently not affordable in most developing countries .