The mRMA vaccines are so different in their operation from traditional vaccines that your claim they are similar is spurious. The fact that they’ve been under study for 20 years and never approved till now isn’t an encouraging data point. And contrary to your assertion, it IS possible to have evidence on the impact on transmission. The press report on the Oxford/AstraZeneca said the data pointed to a reduction in transmission, when we’ve seen nothing of the kind with respect to the mRNA vaccines. We also have the issue of the super cold storage requirement for the Pfizer vaccine, and that it can be held at refrigerator temps only for 5 days. And readers have suggested that there aren’t loggers (temperature monitors) on the market that go cold enough to validate that the vaccine has been kept cold enough during shipment. There also aren’t many of the super cold fridges around, whose prior use was storing embryos and they are super expensive, and they are unreliable, so you need redundancy So outside major hospitals, you aren’t likely to find them. That means we will have a largely improvised supply chain with a lot of just in time deliveries to end points. And that also means places that are rural or far from major medical centers will have more supply chain risk.