Will a COVID (or flu) vaccination affect my blood results?

[mantana]

If I have a blood test 3 or 7 days after a COVID (or flu) vaccination - will it affect my blood results? Should I perhaps make the vaccination after the blood test, so that there is no potential issue interpreting my blood results? If the vaccination affects blood results - how many days after the vaccination should I wait before doing a "regular blood cancer blood test"? 7 days? 14? 30? That's assuming I'm flexible with setting up appointments and I'm not skipping any tests/consultations.

[LeoPa]

It could but it's not a given. However if you have some flexibility I would do the vax after the blood draw.

[Skyshark]

I'm on treatment with Venetoclax + Obinutuzumab. They like me to have vaccinations in the middle of the cycle, 14 days after and 14 days before blood tests. Since being on V+O I run a high temperature >37.5°C while asleep for 2 nights after the vaccination and feel terrible for the 2 days after.

[MovingForward4423]

it’s likely to push up your lymphocytes count, and others as you react to the vaccine. I was asked to wait a week after a vaccine before having my blood work for a review.

[RSilver]

It did affect my results pre treatment for CLL. It increased my lymphocytes. My blood work was done a week late after the vaccine. Thankfully my Specialist is a bit of a Sherlock Holmes and figured out the reason for the increase.

[Teddo]

I had my last covid booster on 9/22/23, followed by blood work on 9/27/23. ALC was 91,520, a big drop from111,857 on 6/21/23. On 10/27/23 it was back up to102,100 and on 12/28/23 it was 126, 745, my all time high. As we know ALC does jump around. The covid shot did not increase the ALC and likely had no bearing on the count.