Researchers conclude that there is a hierarchy of HIV subtype fitness

In a recent public lecture, investigator at the KwaZulu-Natal Research for Tuberculosis and HIV and Victor Daitz Chair in HIV/TB Research, Professor Thumbi Ndung’u, presented a summary of a series of studies in which his team investigated biological differences between HIV-1 subtypes, focusing on the Gag and Nef genes that are important for HIV replication. 

The researchers concluded that there is a hierarchy of HIV subtype fitness with subtypes B, D and recombinants the most fit viruses whereas A and C are the least fit viruses. They say this is consistent with subtypes B and D being associated with faster disease progression whereas A and C are less pathogenic (or more attenuated) and may therefore be associated with slower disease progression. 

Interestingly, Ndung’u proposed that decreased pathogenicity may be advantageous for the epidemic spread of subtypes A and C since individuals infected with these viruses may live longer and transmit more.  He also proposed that there may be other viral factors that enhance the transmission efficiency of subtypes A and C that will require further investigation.

Read the full article here.

Publication Date: Sep 2015