The killed vaccine used against polio virus has following features EXCEPT?

The killed vaccine used against polio virus has following features EXCEPT?

پولیو وائرس کے خلاف استعمال ہونے والی ویکسین میں درج ذیل خصوصیات ہیں سوائے کن چیزوں کے؟
Explanation

Salk vaccine IPV consists of inactivated (killed) poliovirus strains of all three poliovirus types