[koheripbal]

High fevers are not uncommon in babies receiving their first vaccines.

I'm not sure it indicates a problem. A fever is, itself, just an immune system response, not a "symptom" of disease.

You are correct that there is a threshold beyond which a fever becomes unsafe, but it's above 103. But fevers of 103 in the test group do not indicate that fevers of say 105 will occur in some patients.