Risk of transmission during primary infection in people on CAB-LA PrEP

[ValentinaCambiano]

Within the Synthesis model the risk of transmission during primary infection does not depend on VL.
There is evidence that people infected while on CAB-LA PrEP have a low VL during primary infection and so they are likely to have a reduced chance of transmission.
Considering having a reduced chance of tranmission if a person is on PrEP and on CAB-LA PrEP.
Not sure whether this should be considered as well for TDF/FTC oral PrEP

[andrew-phillips-1]

I think it's a good point that we should consider this (for CAB-LA). I'm just a bit nervous about making the changes as we will need to feed back in from the previous period the proportion of people in primary infection who are on CAB-LA.

More generally, I hope you agree that we should merge this branch into Core at some time soon. I think we will have to all go through it together slowly to resolve any conflicts.

[ValentinaCambiano]

You are right that the proportion of people in primary infection who are on CAB-LA is going to be very small. Maybe as 1st step (and you might have already done it) we should export how many new HIV infections are in people on CAB-LA or which proportions of new infections are on people on CAB-LA. If this is a very small % maybe it does not matter too much in terms of transmissions.
I'm just thinking that an increasing and substantial proportion of new HIV infections in the Synthesis model come from people in primary infection.

[andrew-phillips-1]

Thanks - yes I might try that. If I try to change the code I might send you a before and after to compare on notepad++ to check you agree.

[ValentinaCambiano]

sure