[sdenton4]

There's a well established alternative for flu already? It's like asking why electric engine cars have taken so long to overtake petrol cars; there's a giant existing infrastructure and well known protocols for flu already, so the risk/reward balances aren't great for the newcomer.

[dhdhhdd]

Otoh having an established baseline can help understand the efficacy and cost comparison (and time to market), and with new technologies you might want to play it safe?

[anonporridge]

An emergency like Covid is the ideal environment to dismiss all concerns about efficacy and cost. The risk to losing some money on a failed vaccine is negligible compared to the cost dragging out the restrictions even just a little bit longer than necessary.