I also think they are cottony camelia scales. They are too large for whiteflies and they are rod shaped vs the triangular shape of the whitle flies who should also be flitting around the plant when they are disturbed. I don't see the circular egg patterns and white flies should be less of a problem at this time of the year.
Scale can be hard to get rid of once they get past the crawler stage as their coating provides them with protection. Neem will work on the crawlers but I would use some physical scrubbing aswell. When scales die they remain on the plant so it is hard to tell if they are dead or not. It is possible to physically remove the scales if the plant is small and you want to be more organic. Otherwise, a systemic will work better at killing the scale. I would use systemic rose care because it lasts for about 6 weeks vs a year for Merit to limit the impact on beneficial insects. It will be better if the plant can be isolated.
https://oregonstate.edu/dept/nurspest/co ... 0scale.htm