My baby will have her vaccine tomorrow. What can I do to prevent her from getting fever?

Breastmilk is the best prevention. I have been exclusively breastfeeding my baby since he is borned. He is 6 months old now and he has never developed fever after all his past vaccinations including 5-in-1, rotavirus and pneumococcal. Breastmilk is known to be able to increase baby's immune system.