Which immune response is primarily induced by both the oral Sabin and the parenteral Salk vaccines against poliomyelitis?

The correct answer reflects the primary immune response elicited by both the oral Sabin and parenteral Salk vaccines against poliomyelitis, which is the production of neutralizing antibodies in the circulation.

The Salk vaccine, an inactivated vaccine, induces a humoral immune response by stimulating the production of IgG antibodies in the bloodstream. These antibodies are specifically developed to target the poliovirus, preventing it from entering cells and causing disease. The oral Sabin vaccine, being a live attenuated vaccine, also promotes a strong humoral response, leading to the synthesis of both IgM and IgG antibodies.

This production of neutralizing antibodies is a crucial aspect of vaccine-induced immunity as these antibodies can neutralize the virus effectively, providing systemic protection against poliomyelitis. The presence of circulating neutralizing antibodies indicates an effective immune response capable of preventing infection upon exposure to the wild poliovirus.

In the context of the immune responses listed in the other options, while CD8+ T cell activation can be part of the immune response to viral infections, it is not the primary mechanism elicited by these specific vaccines. The main goal of both the Sabin and Salk vaccines is to elicit a robust antibody response, thus ensuring that