Respuesta :
Answer: The infuenza Virus mutates often so a new vaccine will be needed to fight the stronger, more adapted version of the virus.
Answer:
the virus is constantly mutating each year requiring there to be different vaccines
Answer: The infuenza Virus mutates often so a new vaccine will be needed to fight the stronger, more adapted version of the virus.
Answer:
the virus is constantly mutating each year requiring there to be different vaccines