Here is a bit of a longer explanatory thread on our recent paper on “Infectious viral load in unvaccinated and vaccinated patients infected with SARS-CoV-2 WT, Delta and Omicron”. You can read the full paper here: medrxiv.org/content/10.110… As the title says we are determining infectious viral load. So what is the difference to RNA or genome copies viral load. An infectious virus is rather easy to understand, it is a virus particle that can infect another cell/human being and produces progeny virus particle.

Short thread on this table which is shared widely and leads to the (false) conclusion that a heterologous boost with 2xPfizer/1xModerna is superior to a homologous boost with 3xPfizer. 1. The moderna booster given in this study was a 100ug dose whereas the approved moderna booster is only a 50ug dose, which would lead to somewhat lower antibody levels. Therefore the difference would be even smaller.

1. Since there was a huge discussion about T-cell mediated immunity following the Lancet comment on seroprevalence by @EckerleIsabella and me, I'd like to share my thoughts on this in the following thread: 2. There are 2 different points that are discussed at the moment:
First, there are some studies, i.e. tinyurl.com/y8zzf8tw, that show a cross-reactive T-cell response in sample taken before the pandemic, due to previous infection with common cold coronaviruses.