Antigenic drift refers to the gradual mutation of viral antigens, allowing the influenza virus to evade the host's immune response.

Hepatitis B virus is primarily transmitted through blood and bodily fluids, making it a bloodborne pathogen.

T helper cells play a crucial role in the immune response by activating B cells to produce antibodies and cytotoxic T cells to kill infected cells.

The rapid antigen detection test is commonly used to quickly diagnose streptococcal pharyngitis by detecting Group A Streptococcus antigens.

Gram-negative bacteria have an outer membrane that contains lipopolysaccharides, which is a key characteristic distinguishing them from Gram-positive bacteria.

Norovirus is a leading cause of gastroenteritis outbreaks, especially in children, due to its high transmissibility and low infectious dose.

Live attenuated vaccines contain live pathogens that have been weakened so they cannot cause disease but still elicit a strong immune response.