No, I meant that the reverse transcriptase process is an extra step that adds time. I agree that this amount of time may be short, but certainly not trivial. Compared to a DNA virus extra steps, and therefore time, is still required when generating the initial expression vector for an RNA virus. Since we are considering the amount of time it takes to generate a new vaccine for a new strain of flu (and not the generation of additional VLPs from cassettes already incorporated into an expression vector), any extra steps could potentially end up being giant time sinks in the event a key step in the process goes awry. This is why I feel you should not discount the reverse transcriptase event, or really any single step along the way, as trivial.

Agreed, but there are some barriers in the way of ever getting this type of vaccine approved. Most likely these virus-like particles are being expressed by some sort of transformed (cancerous) cell line. Given that this is so, there are some safety issues involved with injecting test subjects with potentially carcinogenic material. They will likely need to find a new way of expressing these particles if they ever hope to use them clinically.

This actually could affect the speed of how quickly the vaccine is made, as more work would be need to done to get the viral genomic information from an RNA virus into a form that could be stably transfected into a cell. Most expression vectors would require a complementary DNA expression cassette for the genome of RNA viruses, which would need to be generated in a lab. Admittedly this would not add on a large amount of time, but still more time would be needed to make a vaccine from an RNA virus versus a DNA virus.