Question

I am doing a virology report. It says to distinguish between INTRAsubtype reassortment of a virus and INTERsubtype reassortment of a virus. I'm just confused what this means? specifically talking about influenza A virus. Thankyou :)

Answer 1

Intra subtype Reassortment	Inter subtype reassortment
This is the process of segment reassortment between different lineages of the same sub type of influenza A virus.	This is the process of segment reassortment that occurs between different influenza A virus subtypes. Influenza A has 18 HA subtypes and 11 NA glycoprotein subtypes.
Intra subtype reassortment is required for evolution of all types of influenza viruses, spread of infection, severity of disease and also efficacy of vaccines. For example, the reassortment in H3N2 influenza virus caused resistance to adamantine drugs (effective against influenza A virus) worldwide. This is because of increased rate of amino acid replacements. Thus, intra subtype reassortment leads to increased virulence.	It causes changes in antigenic properties so that there is minimal or no immunity generated against the virus in the general population. This will affect the immunity to all subtypes of the virus. In some cases, the reassorted virus can increase host defense mechanism or host adaptations. This reassortment can cause subtypes to infect different host species. Equine influenza virus has now been able to infect dogs in addition to horses due to complete transfer of EIV H3N8 to Canine influenza virus.
High genetic relatedness and functional compatibility between the lineages allows increased reassortment.	This reassortment is restricted. This is because there is increased segment incompatibility and mismatch.
Viral evolution is majorly affected by intra subtype reassortment, even overcoming the adaptive antigenic drift changes. There is high viral fitness.	Segment incompatibility causes low viral fitness. There is also less spread to the population of the reassorted viruses and cause infection.
Intra subtype reassortments cause larger variation that inter subtype reassortments.	Inter subtype reassortments cause smaller variation that intra subtype reassortments.