Peginterferon alpha 2a or 2b for hep b?

[Jatashankar]

I have taken 18th shot of peg 2b and by every next injection feel like y m I taking it, it's not the right one. I have to pay a lot for interferon therapy and which is going vane as no significant response yet. Peg 2a is FDA approved but nowhere I can find 2b is EASL approved for hep b. Plain IFN 2b was FDA approved though but not peg 2b.
Many of u will say me to continue 2b (Atleast upto 24weeks) and not shift but I want some evidence or studies that changing won't benefit me.
There is a Chinese study in which peg 2b was beneficial only in geno c and age<25. I m 32.
I talked to pegasys customer care and they said not to change or if I want then I should give one month gap then start 2a. So will it be reasonable to stop for 1 month or continue by immediate shifting to peg 2a.
Kindly help me with logical explanations and if possible with some study reports of such shifts and that peg 2a is superior to 2b.
All of u r welcome to share ur views.

[Jatashankar]

Thanx Steff and studyforhope! 19th injection will be pegasys! It comes by the name of Exura by Roche in India. One thing I should say to myself that I should not expect some wonder to happen on changing but will it be safe in context to inmunological point of view. Though I'll be certainly changing to 2a next week.

[studyforhope]

the 40 kilodalton pegasys has a superior maintenance of plasma levels over one week. it is 40% compared to only 9% with peg 2b after one week, thus much more consistant suppression of viral activity is achieved.
You can change immediately, no need to wait for one month.

[stef2011]

pegasys is better, scientifically i am not sure, but most studies on hbv are done with 2a and that s what is used for treatment