your bb has fever now? maybe you can really consider having the 6-in-1 in private doctor's clinic 1 to 2 weeks later. no problem even your bb had previous vaccines in the public clinic. you can discuss with your doctor. i think it is ok. indeed, Hib vaccine can be given to child below 5 year old (even following our vaccination schedule, i.e. evenyou missed the previous 2 doses) and can be given separately.