Which one of the following best describes the Sabin polio vaccine?

The Sabin polio vaccine, also known as the oral polio vaccine (OPV), is a live attenuated vaccine that carries a small risk of causing disease. This characteristic is significant because, although the vaccine is effective in providing immunity, the live attenuated strain has the potential to revert to a more virulent form in rare cases, potentially leading to vaccine-derived poliovirus (VDPV).

The ability of the Sabin vaccine to replicate in the intestinal tract enhances the immune response, particularly in the gastrointestinal tract, where poliovirus typically infects. This results in both systemic immunity and mucosal immunity, which is effective for preventing transmission of the virus. While it is a key feature, this characteristic directly contrasts with the characterization that it provides little gastrointestinal immunity.

The vaccine is also not prepared with an inactive virus; that description pertains to the Salk vaccine, which uses inactivated virus. Additionally, the Sabin vaccine is administered orally rather than by injection, further distinguishing it from other forms of polio vaccination. Thus, identifying the small risk of disease associated with the Sabin vaccine accurately captures its unique profile and informs about the safety considerations in its use.