Myth: After getting influenza A, the body will also develop immunity to influenza B in the short term, because they are all flu.
Truth: Influenza A and influenza B are two different subtypes of influenza that do not have a cross-immune mechanism. Specific antibodies produced after infection with influenza A viruses do not provide effective protection against influenza B infection, and vice versa. In other words, after having been infected with influenza A, if the patient is relatively weak, he or she may still be infected with influenza B.
In general, there is a small chance of infection with the same subtype of influenza virus within a year. For example, if the A(H3N2) subtype of influenza A virus is currently circulating, and the patient will have immunity to this type of virus after infection, the probability of reinfection with the same type of virus within one year is small. However, because influenza A viruses mutate easily, people who have not been vaccinated against influenza may be reinfected with other subtypes of influenza A viruses. In recent years, because the influenza B virus has not mutated much, the spread is relatively small, and the probability of reinfection with influenza B within a year is also small.
With the Spring Festival approaching and the increase in social mobility, those who have not been infected with the influenza virus can seize the opportunity to get vaccinated against the flu. In addition, schools and residences should pay attention to regular ventilation, especially if there are flu patients at home, they must be kept ventilated to reduce the concentration of viruses in a closed environment; Reduce going to densely populated places, and be sure to wear a mask when going to public, especially when going to the hospital; Daily nose washing with saline can help reduce the probability of viral infection.
*: From the January 2024 edition of Science's Myth List.