DPT vaccine (Triple vaccine) is a combination vaccine against three diseases – Diptheria, Tetanus and Pertusis. Currently, DPT is also Commercially available as combination vaccines with HBV and/or HIB vaccine. Two other related vaccines are – DT (devoid of pertusis component), and DTaP (containing only acellular component of pertusis bacilli).
Contents: DPT contains diphtheria toxoid (25 Lf) tetanus toxoid (5 LI) and killed whole cell pertusis bacilli (20,000 million). Due to the presence of whole cell pertusis bacilli, it is also written as DTPw.
Supply & storage: It is available as single dose or multi- dose vials, which should be stored in middle compartment of refrigerator (2-8°C). DPT vaccine should never be frozen.
Dosage & administration of DPT vaccine: 0.5 ml of vaccine is given IM over lateral aspect of thigh. It should not give over gluteal region in infants, due to the risk of sciatic nerve injury and erratic absorption.
Schedule of administration: Primary doses are given at 6th, 10th and l4El week of life, followed by two boosters – at 15-18 months and 5 years. Under national immunization schedule, 5th year booster is given as DT.
Protective value is 100% for diphtheria and tetanus and 80% for pertusis. Efficacy of DTPw and DTaP is comparable.
Dpt vaccine side effects
They are mainly due to its pertusis fraction and may be minimized with use of DT or DTaP vaccine. These include Local pain, swelling and tenderness, which may be relieved with cold compresses. It also includes Transient fever in first 24 hours, which may be prevented or treated with a simple antipyretic e.g. paracetamol. Occasionally, it may lead to febrile seizures. Moreover, it also includes Neurological events e.g. screaming episodes, seizures and very rarely, encephalopathy.
Contraindications of Dpt vaccine side effects include Progressive neurological disease, and History of serious adverse events with previous dose.
In these cases, DT or DTaP should be used for subsequent doses. Other important issues:
• Although Dpt vaccine side effects are less common with acellular vaccine DTaP than regular DTPw, lAP recommends use of DTPw instead of DTaP for universal immunization due to comparable protective efficacy and less cost. DTaP may be used in affording children.
• DT is used for 5 year booster in National immunization program or primary immunization in children beyond 5 years, due to less side-effects and relative rarity of pertusis beyond this age. However, lAP recommends use of DTPw, rather than DT as 5thi year booster.
• TAP recommends DTaP instead of TTITd as 10 years booster, due to continued risk of pertusis beyond this age.