RE: Is it my imagination19 Dec 2021 23:36
Kickthepuss- my response to that video. First off, guy is great at explaining things clearly, however I am a bit annoyed as what he is summarising here is a press release, not the original data (below) or paper online (not available). He noted its not peer reviewed yet, which means all results have big tentative on them. That said, a lot of Omicron data is hitting headlines before per review, so not much option and that's not his fault. So, let's go.
I'm looking at the video and raw data as I would if i was reviewing it : so really probing to see how robust it is. This is therefore a bit of an aggressive response, but that's a good peer review litmus. It's also a bit technical and assumes u watched the video u linked me. Skip next paragraph for headline conclusions.
The work appears to be both interesting and relevant, though the ex vivo study has several limitations. Some of which were mentioned, but an important one missed is that in the patient the bronchi cillia form part of the Mucosal elevator to clear the lungs, so a severe infection that disabled the elevator (common in respiratory infections) could lead to poor drainage and so build up of fluids in alveoli, even if viral replication there is lower. This would also allow viral particles to be carried down from bronchi to alveoli, meaning different replication rates may not be as important at implied to disease course. In particular, I note from the actual data the work is based on (link below) that delta also showed less replication in the lung tissue than the original strain, yet we saw no drop off in severity with delta compared with original. Statistical significance is only calculated for original vs Omicron, not delta vs original or delta vs Omicron, which seems like an oversight here.
In conclusion, the work presented (that is currently available to see) appears to reliably show an increased transmissiblity, but does not lead to a conclusion of reduced severity. If Omicron severity is lower, the proposed mechanism of reduced viral replication in alveoli is questionable given the similar change seen in delta that did not lead to lower severity. The paper purposes a mechanism for lower disease severity, but does not establish this here.