This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Virology, Subject name: Microbiology
Influenza vacccines is administrered - 
Select and explain. 
A. Intranasal instillation, B. Intradermal, C. Nasal drops, D. Intrathecal
A: Intranasal instillation
Answer: A: Intranasal instillation 
Explanation: The earliest vaccine was the virus attenuated by repeated egg passage. These administered by intranasal instillation REF:ANANTHANARYANAN TEXTBOOK OF MICROBIOLOGY 9EDITION PGNO.504