Fever after taking jab

Assalamualaikum.

Hari ini saya ada something serious untuk diutarakan dan saya nak mintak u ols share experiences and also advises.

Begini ceritanya,
Pernah tak u ols perasan or alami or perhatikan, some of babies bila lepas jab/vaccinated je, mesti demam. Kalau tak teruk pun, mungkin akan ada slightly fever. True or not? And perasan tak the nurses pun akan bagi kita PCM syrup untuk kita bawa balik. Standby kot kot anak demam katanya.

Penah? Pernah?
Hmmm.. Persoalannya, why was that so eh?
Ada terfikir tak?

Memula dulu, I was thinking mungkin sebab babies terkejut tiba-tiba kena jab.
But then, I did some readings, I found pasal the effects of vaccines.

Tapi.. Tapi.. Tapi..

I was too late la sebab at that time my baby girl dah lepas her 6 mo jab and also 3rd dose of pneumococcal.

I do some discussions jugak dengan some friends yang juga merupakan emak-emak kepada babies ni kan. Some are taking vaccines, and some decided not to take vaccines.

Me? Masih ada around 2 months untuk decide betul-betul for the best untuk baby girl saya.

And currently, I feel like... hmmmm.. (biarlah rahsia dulu, nanti dah dapat petunjuk, saya reveal ok?)

My doter was suspected having bronchitis. I fed her with VCO (Virgin Coconut Oil) daily. Alhamdulillah, after few days, nampak perubahan. She's having cough like every month since her last jab since September 2012. Some are saying that it is because of the jab/vaccine.

Last week, I went to paed somewhere in Melawati and did a suction procedure. Alhamdulillah, she's getting better.

Tapi still, saya susah hati sebab mungkin perkara sama akan berulang lagi.

Hmmmm. Buntu mak, nak.

So now, the question is (after all the rumblings)
Fever after taking jab, why is that so? 
Kenapakah ini terjadi?
Can somebody explain to me? 
Medical people are most welcome... 
Non-medical people pun saya nak tahu jugak if you guys have any idea..
I don't mind if u wanna use medical terms since I can google the translations. 
Please.. I need somebody to clarify.
Mommies, please share your experiences.

Thank you so much.