Some quick updates, as today is very busy at work:
(1) Intriguing preprint from Cambridge U., via Yves [not Cohen]:
http://doi.org/10.1101/2020.04.10.20053207https://www.medrxiv.org/content/10.1101/2020.04.10.20053207v1.full.pdf+html
Franklin, R.; Young, A.; Neumann, B.; Fernandez, R.; Joannides, A.; Reyahi, A.; Modis, Y. Homologous Protein Domains in SARS-CoV-2 and Measles, Mumps and Rubella Viruses: Preliminary Evidence That MMR Vaccine Might Provide Protection against COVID-19. medRxiv 2020, 2020.04.10.20053207.
The COVID-19 disease is one of worst pandemics to sweep the globe in recent times. It is noteworthy that the disease has its greatest impact on the elderly. Herein, we investigated the potential of childhood vaccination, specifically against measles, mumps and rubella (MMR), to identify if this could potentially confer acquired protection over SARS-CoV-2. We identified sequence homology between the fusion proteins of SARS-CoV-2 and measles and mumps viruses. Moreover, we also identified a 29% amino acid sequence homology between the Macro (ADP-ribose-1’’-phosphatase) domains of SARS-CoV-2 and rubella virus. The rubella Macro domain has surface-exposed conserved residues and is present in the attenuated rubella virus in MMR. Hence, we hypothesize that MMR could protect against poor outcome in COVID-19 infection. As an initial test of this hypothesis, we identified that 1) age groups that most likely lack of MMR vaccine-induced immunity had the poorest outcome in COVID-19, and 2) COVID-19 disease burden correlates with rubella antibody titres, potentially induced by SARS-CoV2 homologous sequences. We therefore propose that vaccination of ‘at risk’ age groups with an MMR vaccination merits further consideration as a time appropriate and safe intervention.
Excerpt from Figure 4 of the paper:
(2) John Campbell has more on strokes as a complication of excessive blood clotting in severe COVID19,
https://www.nejm.org/doi/full/10.1056/NEJMc200978
as well as on a preprint from Indonesia that appears to show a very strong link between vitamin D deficiency and COVID19 mortality:
(3) Good news for people who are on ACE inhibitors and ARBs (angiotensin release blockers):
Spin, strangeness, and charm 
The MMR one is very likely to be the effect of spurious correlation IMO. That cohort is also most likely to be poorly covered is also the cohort most likely to have exacerbating circumstances and pre-existing conditions.