> Flu and corona are both “common cold type” viruses No. Flu, COVID, and the common cold are caused by different viruses that all lead to respiratory illnesses; influenzaviruses, coronaviruses and rhinoviruses respectively. These viruses target their own set of receptors and have their own mechanisms for multiplying. One technique used against one of them may not work on the other. > The immense speed at which mRNA vaccines can be developed might improve that in the future In theory, I agree that mrna could be faster; if there's some change in part of the virus, you can just edit the mrna sequence to reflect that change and ship it back to production instead of starting again from scratch. Will the logistics and the economics follow the theory? I guess we'll see.