Studies on a single-dose capsule preparation of Poliomyelitis vaccine.

In view of certain difficulties involved in the administration of poliomyelitis vaccine in liquid form on sugar or in syrup in mass campaigns, trials have been conducted with a new single-dose preparation of live attenuated poliovaccine (Sabin strain) in an emulsion in a gelatin capsule. Each capsule contained a standard dose of vaccine which was shown to be stable in this form. It has been demonstrated that the capsule vaccine was as effective as liquid vaccine both in children and in adults. The capsules were acceptable to adults and children over the age of 5 years, but between 6% and 7% of 4-5-year-old children refused the vaccine in this form owing to difficulty in swallowing the capsules.The authors consider that the capsule may be recommended for the routine immunization of older children and adults and for mass vaccination campaigns. It is suggested that the vaccine could be administered to young children and babies in the course of such campaigns by opening the capsule and mixing the contents with water or sweetened liquid in a spoon.