There are already three clinical trials with the BCG vaccine for elderly/adults before the COVID-19 pandemic showing its efficacy against pneumonia, acute upper respiratory tract infection(AURTI), and H1N1 influenza
I have added a few related clinical trials done before the COVID-19 pandemic in the original article but I guess many people don't notice. Let me introduce them here. There many papers regarding trained immunity among children with BCG vaccination but I have been looking for clinical trials with adults, especially seniors since they are vulnerable with COVID-19. And I have found three papers so far. 1. A randomized clinical trial for bedridden elderly people in Japan in 2003. BCG re-vaccination significantly reduced the probability of pneumonia. Prevention of Elderly Pneumonia by Pneumococcal, Influenza and BCG Vaccinations https://pubmed.ncbi.nlm.nih.gov/15732353/ https://medical.nikkeibp.co.jp/inc/all/hotnews/archives/237265.html (A little detailed article in Japanese) No BCG strain info obtained but I guess this trial was done with the BCG Tokyo strain since it was done in Japan. Below is a machine translation of https://medical.nikkeibp.co.jp/inc/all/hotnews/arc...