Acute diarrheal disease.
Infants(Child under 1 year) who are under formula feeds are prone to develop diarrhea.
Past week of cold
indicates that the diarrhea is due to viral infection.
The most feared things are dehydration(water loss from the body) and secondary bacterial infection.
In this situation my advice would be to continue oral feeds to compensate the water loss.
Consult a pediatrician
. He will help with the treatment and alway advise you on vaccination
Hope the answer helps you.
Let me know if there is any clarification.