Final answer:
The Sabin polio vaccine is taken orally and contains an attenuated virus, whereas the Salk vaccine involves an inactivated virus administered by intramuscular injection. Due to a risk of transmission from the live virus in the Sabin vaccine, countries with low polio rates prefer using the Salk vaccine.
Step-by-step explanation:
The Sabin polio vaccine differs from the Salk vaccine in several ways. The key distinction mentioned in the student's question is that the Sabin vaccine is administered orally, which means it is taken by mouth. This method is in contrast to the Salk vaccine, which contains an inactivated virus and is delivered through intramuscular injection. The Sabin vaccine features an attenuated virus and mimics the normal route of infection, which offers the advantage of inducing both a systemic and a local gut immune response, thereby lowering the likelihood of spread within communities. Furthermore, the utilization of the Sabin vaccine can, unfortunately, lead to the shedding of attenuated viruses in the feces of immunized individuals, which carries the potential for transmission, especially in areas of low sanitation. Thus, countries with very low rates of polio infection, like the United States, have opted to use the Salk vaccine to avoid the potential risk of vaccine-derived poliovirus transmission.