Adding new chicks to chicks

[Sierrab]

I had 12 chicks that are a 1.5 weeks old and just picked up 6 chicks same age. The new chicks have not been vaccinated.

I have given the previous 12 chicks Corrid since they were not vaccinated either.

Can I give Corrid to all of them again or do I need to separate the new set for the required 5 days of the medicine?