Salk polio vaccine is ?

Ans. is 'a' i.e., Killed Inactivated polio (Salk) vaccine IPV is usually made from selected wild polio virus (WPV) strains-namely, Mahoney (Salk type 1), MEF-1 (Salk type 2) and Saukett (Salk types) - that are grown in vero cell culture or in human diploid cells. Vaccine contains all the three types of poliovirus, inactivated by formalin, i.e. killed vaccine. It contains 40, 8 and 32 D antigen units of type 1, 2 and 3 virus respectively (Previous vaccine had 20, 2 and 4 D antigens, according to 20th/e of Park). The primary or initial course of immunization consists of 4 inoculation (4 doses). The first 3 doses are given at intervals of 1-2 months and 4' dose 6-12 months after the third dose. First dose usually given when the infant is 6 weeks old. Additional doses are recommended prior to school entry and then every 5 years until the age of 18. Being an inactivated vaccine, it can be given to immunosuppressed individuals, e.g. AIDS patients. IPV is administered by IM injection (preferred) or subcutaneous injection. It can be combined with DPT, Hepatitis, and/or H. influenzae type B vaccine. In the combination vaccines, the alum or the peussis vaccine, or both have an adjuvant effect.