I have not heard about the COVID vaccine interfering with IFN efficacy.

Pegasys (peginterferon alpha 2a) can take quite some time to reach efficacy for some people with MPNs. It would make no sense to make big changes in the absence of giving the medication time to do its work. The MPN Specialist said to wait for at least 6 months for a reason. Some have taken longer to see the desired response but did ultimately achieve target.

I am not sure what medication they are talking about switching you to. Besremi (ropeginterferon alpha 2b) is the only interferon with an indication for MPNs. I am not sure why they would recommend switching the interferon type of at this point. I would ask for a clear explanation of the rationale.

It would make more sense to change the type of cytoreductive medication if the interferons are not going to work for you in the long-term. There are other options depending on your MPN profile. I would arrange to consult with the MPN Specialist before making any decisions.

Wishing you success moving forward.

I am not sure where "here" is, but it is a universal truth that assertive patients receive higher quality care. Passive patients do not. This is true everywhere. We have to be educated about our conditions and our own best advocates. We each have to set our own treatment goals, define our risk tolerance, and decide about our treatment preferences. If you wish to set the goal to reach hematologic targets in 6 - 12 months, with acceptable risk of adverse effects based on your definition, then that is the correct approach.

It is important to bear in mind that with ET, there is no particular value to keeping platelets levels below 450. The risk of thrombosis is more about how the platelets behave than their absolute number. It is also worth noting that people with the CALR mutation have a lower risk of thrombosis than with the JAK2 mutation. Unless you have a history of thrombosis or hemorrhage, there does not need to be a big rush to normalize the platelet levels.

Wishing you success moving forward.

I totally agree and think the same, i cannot really understand the rush the doctors have and i want to wait these famous months before escalating.
It's so frustrating do not trust your doctor and have to fight always for everything, unfortunately I do not have any other options here..