Will a High Vaccination Rate Affect Contact Tracing?

[bhobba]

I heard an immunologist say the other day that once a high vaccination rate is achieved, contact tracing will likely not be effective. I can sort of understand why. Does anyone from places with a high vaccination rate know if contact tracing is still an effective measure? It is very widely used in Australia. If it no longer has value, it could hamper our efforts to contain it. Of course, vaccination itself helps greatly in controlling the pandemic.

Thanks
Bill

 

[BillTre]

I don't understand why this would be.

I would think that contract tracing would be less effective in populations with high rates of infection.
Too many infected people to make a reasonable attempt at figuring out all of their contacts impossible.
This seems to be the case in much of the US, maybe not now though as infection rates are going down.

As the infection rate lowers, there would be a better ratio of infected to trackers.
This should make it more feasible to track all infected people.
In addition, the infected will be fewer and could receive better treatment.
It really annoys (exceedingly much!) me that when this was first getting started here in the US, whoever was in charge, were not resolute enough to try hard to indentify, isolate, and treat all the infected people, early on.

Your question about high vaccination rates, to me implies low rates of infection, and thus a more feasible possibility of tracking infections in the population.

Maybe "they" think its not effective because they expect infections to continue dropping, or perhaps antibodies in the blood confound an antigen test.
However, there are other diagnostic methods, and I prefer a more cautious approach.

 

[atyy]

With vaccination, we expect the proportion of asymptomatic cases to increase. So contact tracing must take that into account, eg. by testing close contacts even if they are not symptomatic, and by testing them at several intervals to take the incubation period into account. Some contact tracing systems are already doing this, but if they aren't, then they might need to change tactics.