There have been some reports that it’s not necessarily just the R value that is changing for the delta lineage, but also maybe a faster serial interval. Both of these would result in faster spread, but only the R change would affect the immunity you need to damp spread, the interval just means everything happens faster.
Thanks! Somehow I missed that, and I’ll look for next week. Would make all the math much more forgiving, obviously, and make things much less scary. Also makes what happened in India make a lot more sense.
The first thing about this pandemic that’s really confused me is: India is going full hockey-stick → the death rate is suddenly falling in India. Do you know why that was?
Interesting! Do you (or anyone else) have info on what this means about the incubation period? It would be useful to know if it got shorter! Not only for meeting friends or relatives, but also because it means contact tracing becomes easier and lockdowns more effective.
it means contact tracing becomes easier and lockdowns more effective.
I read that oppositely. If the serial interval is shorter, contact tracers need to work faster to inform those exposed, lest those exposed become infected and transmitting. Likewise, lockdowns would only become more effective if the time each person is contagious is reduced. IIRC the delta variant, according to Indian accounts, is significantly contagious for three weeks from the date of infection as opposed to the usual two.
IIRC the delta variant, according to Indian accounts, is significantly contagious for three weeks from the date of infection as opposed to the usual two.
That would clearly make it harder, yeah. And good point about contact tracing. I guess the only thing that would be easier with a shorter incubation period is isolation after flights and getting down case numbers with a very tight lockdown. Everything else gets harder.
There have been some reports that it’s not necessarily just the R value that is changing for the delta lineage, but also maybe a faster serial interval. Both of these would result in faster spread, but only the R change would affect the immunity you need to damp spread, the interval just means everything happens faster.
https://www.researchgate.net/publication/352931648_Transmission_Dynamics_of_an_Outbreak_of_the_COVID-19_Delta_Variant_B16172_-_Guangdong_Province_China_May_-_June_202
Thanks! Somehow I missed that, and I’ll look for next week. Would make all the math much more forgiving, obviously, and make things much less scary. Also makes what happened in India make a lot more sense.
The first thing about this pandemic that’s really confused me is: India is going full hockey-stick → the death rate is suddenly falling in India. Do you know why that was?
Interesting! Do you (or anyone else) have info on what this means about the incubation period? It would be useful to know if it got shorter! Not only for meeting friends or relatives, but also because it means contact tracing becomes easier and lockdowns more effective.
I read that oppositely. If the serial interval is shorter, contact tracers need to work faster to inform those exposed, lest those exposed become infected and transmitting. Likewise, lockdowns would only become more effective if the time each person is contagious is reduced. IIRC the delta variant, according to Indian accounts, is significantly contagious for three weeks from the date of infection as opposed to the usual two.
That would clearly make it harder, yeah. And good point about contact tracing. I guess the only thing that would be easier with a shorter incubation period is isolation after flights and getting down case numbers with a very tight lockdown. Everything else gets harder.