Talk to General Physician on Fever, Body Pain

Meri mother (63 year) ko 2nd shot lagi hai Sinopharm ki. 1st may ko isk 3 din bad unhe flue, fever or pain start howa flue to theek ho gaya lakin 7 din say fever or body pain hai. Pain istarah hota hai k jism ko hath lagane say bhi unhe takleef hoti hai mostly Back and arms muscles main?

Ky ye side effect hai vaccine ka ya kuch or? Need guidance