Thank you for your query on Healthcare Magic.
is a painless vaccine
as it is associated with minimal reactions like mild fever, less pain after vaccination
The fever after pentaxim may be due to some infection which is a coincident with vaccination.
As the child was having cold, this might be the cause for fever in your child.
Nothing to worry and complete the three dose primary scheduled vaccination with pentaxim as advised by your Pediatrician
Hope I have answered your query.