Why do you think the flu vaccine is recommended every year?

Flu vaccines cause antibodies to develop in the body about two weeks after vaccination. These antibodies provide protection against infection with the viruses that are in the vaccine. The seasonal flu vaccine protects against the influenza viruses that research indicates will be most common during the upcoming season. Please give me the brainliest answer?

:) Hoped this helped <3

answer; the tunica intima also called tunica interna, consists of elastic fibers,connective tissue and smooth muscle cells;