Final answer:
Viral neutralization and hemagglutination are both antibody-virus interactions. In neutralization, antibodies prevent infection, while in hemagglutination, antibodies cause agglutination of red blood cells.
Step-by-step explanation:
Viral neutralization and hemagglutination are similar in that they both involve the interaction between antibodies and a virus. In viral neutralization, antibodies bind to the virus and prevent it from infecting host cells, neutralizing its ability to cause infection. In hemagglutination, antibodies bind to the virus and cause clumping of red blood cells, which is visible as agglutination.
For example, in the case of influenza viruses, the hemagglutinin (H) spike is responsible for binding to host cells, while the neuraminidase (N) spike helps the virus release from infected cells. In a hemagglutination assay, the red blood cells are used to detect the presence of influenza virus by visible agglutination. In a viral neutralization assay, the decrease in hemagglutination is measured after mixing patient serum with a standardized amount of virus, quantifying the level of virus-specific antibody.