antiserum vs blood serum

antiserum and blood serum both are nouns.

Word	Noun	Adjective	Verb	Adverb
antiserum	Yes	No	No	No
blood serum	Yes	No	No	No

As nouns, blood serum is a hypernym of antiserum; that is, blood serum is a word with a broader meaning than antiserum:

antiserum: blood serum containing antibodies against specific antigens; provides immunity to a disease
blood serum: an amber, watery fluid, rich in proteins, that separates out when blood coagulates

Other hypernyms of antiserum include serum.

antiserum (noun)	blood serum (noun)
blood serum containing antibodies against specific antigens; provides immunity to a disease	an amber, watery fluid, rich in proteins, that separates out when blood coagulates