CLL Support Association
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Idealisib and flu

Hi everyone

Just another query-thanks for your answers before it is so so helpful to find support in a place like this where there are others who have Come through similar scenarios.

On idealisib have any of you had the flu injection? I ask as my dad has had idealisib-treatment went very well at start really lowered the wbc and then it tapered off-he then got the flu jab and we have just found that it is going back up again-By 20. It's very disheartening but wondering now if it could be the fact he was given the 'flu' vaccine when he already had such a weak immune system.

Anyone else??

Thanks so much for sharing


5 Replies

I'm no medic but if you think about it having the flu jab will make antibodies to fight the flu if you get it.

Stands to reason that wbc may rise initially whilst this is happening however speak to your specialist nurse if you have concerns.



I agree with Cammie and also am not a medical professional, but:

The purpose of a vaccine is to cause the immune system - especially the memory B cells to react and make specific Lymphocytes that recognize the flu virus. So getting a temporary rise in WBC means that the flu vaccine and his immune system worked and he likely will have immunity to the flu.

In general the WBC will bounce around from test to test, so look at or average at least 3 results to see the real trends

Plus you should track the ALC (aka Lymph # or just Lymph) not WBC or Lymph%. That will reduce the "noise" and distortions from other immune functions not related to CLL.

1 like

As I understand it, an 'antigen', i.e. a pathogen or bits of a pathogen (dead virus particles or fragments of bacteria in a vaccine), triggers helper T cells to work together with naive B-Lymphocytes/cells to mutate the B cell receptors into keys that fit the antigen. That's followed by lots of B-cell divisions i.e. clonal expansion, to create B-cell clones producing identical antibodies. That process takes a week or two and is why following an infection or vaccination, your lymphocyte count should increase

Most B-Lymphocytes mature into plasma cells which are antibody factories, but a few become memory B-cells that can survive decades. If a memory B cell later encounters the keyed antigen - e.g. from exposure to the same flu strain covered by the flu vaccine, that triggers the memory B cell to again generate B-Lymphocyte clones that become plasma cells and pour out antibodies.

(All a vaccine does is fool our immune system into thinking it is fighting an infection. When a memory B-cell sees the antigen again for which it is keyed, it doesn't matter whether that memory B-cell arose from a previous infection or a vaccination.)

This memory B-cell activation is much faster than the original process of forming keyed B-cells to the new form of flu, so our body is able to quickly respond to a flu exposure. That's why if we have a flu vaccine and successfully make memory B-cells, we are likely to have a milder form of the flu if we do succumb - our bodies are able to churn out B-lymphocytes to generate antibodies against the flu before the flu gets too much of a hold.

When we have CLL, our CLL cells protect themselves from T-cells which would otherwise recognise them as cancerous and wipe them out. Hence our T-cells don't work very effectively in responding to vaccines...



Thank you all


Not on idealisib but I've been on ibrutinib for 4 years and get my flu vaccine every year. My oncologists (MD Anderson) recommend it.

The flu vaccine, those they use in the US anyway, is a "killed" virus. Here what they caution you against getting are things containing live vaccines like the one for shingles (which I ignored and got anyway once all my blood parameters were back close to normal). Having an impaired immunde system makes you more vulnerable to live ones.

Btw -- as mentioned above, getting any vaccination will generally kick up your WBC a little. That's your immune system signalling that it has found an unwanted intruder. Normally should not last long.

Btw/FWIW - back before I started treatment, and for quite a while after, my general plan for avoiding infection was to have as little contact with other human beings as possible. That's easier for me to do than most people since I'm retired and live in the country but the general approached is the same - avoid crowds. Crowded sporting events, crowded restaurants, crowded stores. Carry lots of hand sanitizer with you and use it. In UK/Europe you are probably more dependent on public transport than we in the car-centric US, but still try to avoid the crowded ones if you can; shift travel times where possible. {Amazon is the disease avoiders friend!}


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