Noun
English Wikipedia has an article on:hemagglutininWikipedia
hemagglutinin (countable and uncountable, plural hemagglutinins)
(biochemistry) An antigenic glycoprotein that causes agglutination of red blood cells
Flublok is made using recombinant DNA technology and contains hemagglutinin produced in an insect cell line. Source: Internet
There is also a vaccine recombinant hemagglutinin influenza vaccine (RIV) that contains no egg protein because it is not manufactured with eggs. Source: Internet