Blood Counts during Induction Chemo

My son (10 year old Stage 4 w Bone/Bone Marrow infilitration) is to start his 4th cycle of chemo (Induction phase of Rapid COJEC) on Friday. We did a blood test yesterday and found his platelets have come down to 53000 from 212000 (75% down) and WBC to 1200 from 12400 (90% down)! Have you seen such drastic changes?
His Haemoglobin has improved to 9.5 from 7.2 and RBC has marginally improved to 3.38 to 2.8.
He had received transfusion after 2nd and 3rd because of low haemoglobin.
I suppose this is probably normal. Any suggestions to sort of maintain levels and avoid infection and transfusion

I recommend consulting your oncologist, blood counts certainly plummet during chemo

This is perfectly normal and expected during chemo, especially rapid cojec. Keep in mind that platelets are always the last to take the hit, so it could take some time before you see them dropping and increasing again.
One word of advice: don’t pay much attention to his general blood work during any kind of chemo. All counts drop drastically, your medical team will intervene where needed with the necessary transfusions. Just make sure that when WBC is really low you keep an extra eye for infections/viruses (avoid going outside and contact people, eat well cooked food and wash everything), and when platelets are under 15-20k watch out for bruising or nosebleeds.

Good luck