COVID-19 vaccine and CLL patients: An analysis of the first published results

Today, the first results of a key study on vaccine responses in leukaemia patients has been published. In this blog, our Patient Advocacy Manager, Charlotte, outlines the first reaction to the news and what the takeaway messages are for patients and their loved ones.

Key points:

  • Initial results of a study from Birmingham on vaccine responses of CLL patients has been published.
  • 34% of CLL patients show antibody responses, rising to 75% after two doses, showing the importance of having both doses.
  • However, CLL patients produced a much smaller quantity of antibodies than healthy people.
  • Certain groups of patients were less likely to respond, including those on BTK inhibitors.
  • The study has a number of limitations to be aware of and you should be cautious in using this data to change your behaviour. Seek advice from your haematology care team as necessary.

Today, the first results of a key study on vaccine responses in leukaemia patients has been published in the Lancet journal. This work focused solely on chronic lymphocytic leukaemia patients; this is a type of incurable blood cancer that affects B-lymphocytes. There had been concerns about this particular group of patients and how they would respond to the vaccine, as CLL patients are known to not respond as well to other vaccines, such as the flu, as healthy people do.

This work was led by researchers at the University of Birmingham, including Dr Helen Parry, who has spoken at previous webinars for Leukaemia Care about the COVID-19 and blood cancer patients. The study included both those who had received the Pfizer-BioNTech vaccine and some people who had received the Oxford-AstraZeneca vaccine. It is important to note that this work is a pre-print; this means that the work has not been fully peer-reviewed by scientists outside of the team that conducted the trial. Therefore, the results should be interpreted with some caution.

The headline result brings some welcome news to CLL patients. Only 34% of patients showed an antibody response after their first vaccine (94% of healthy people of the same age have antibodies after the first dose). However, this improved markedly after the second dose, where 75% of CLL patients showed an antibody response (compared to 100% of healthy, age matched people).

However, CLL patients were shown to have over 100 times lower amounts of antibodies. This means that they have produced antibodies, but much smaller amounts than in healthy people. We don’t fully understand the impact of how many antibodies you produce, but this is a concern.

Additionally, it’s important to note that not many people had had a second dose in these early results. 75% responding after a second dose shows potentially positive news, but we need as much data as possible about more people after a second dose to be sure of the responses.

The study also looked to see whether subgroups of CLL populations were less likely to respond than other CLL patients. Unfortunately, patients who were being treated with BTK inhibitors (e.g., ibrutinib, acalabrutinib) were less likely to make antibodies after vaccination. Those patients with less IgA antibodies in their blood in general (meaning they struggle to make antibodies to many diseases) were also less likely to form antibodies after vaccination. Therefore, it seems that more work is needed to support these patients; the researchers suggest further vaccination programmes and better COVID treatments will be needed into the future.

Finally, this study used different ways of sampling patient’s blood. Some patients had their blood taken as if they were having a blood test, submitting a vial of blood. Others conducted a finger prick test and submitted the test as a dried spot of blood. Whilst this enabled more people to participate with an easier option, the finger prick test is less reliable than a full blood test, so this may have impacted upon results. For more information about finger prick antibody tests, please see our blog on the topic here.

In summary, this study has shed some light on those most at risk in the CLL population and gives others cause for hope. However, we would advise that you interpret results with caution and remain vigilant against the risk of catching, as the limitations of the study prevented the researchers from being able to give further advice to patients. If you wish to discuss these results and their relevance to you, we recommend you discuss at your next routine appointment.

You can read the original paper here.

Need advice or support about anything discussed in this article?

After a blood cancer diagnosis, it’s understandable that you or your loved ones will have questions. Our Nurse Advisors are available across a range of services to give you the expert advice you need, from diagnosis, to treatment and beyond. However, our nurses cannot diagnose or treat you over the phone. In case of an emergency, please contact your medical team or call 999.

You can speak to a nurse on the following services:


Our Nurse Advisors are available every weekday on our free helpline. You can speak to a nurse at the following times:

  • Monday – 9am – 5pm (excluding Bank Holidays in England)
  • Tuesday – 9:15am – 2:15pm
  • Wednesday – 9:15am – 2:15pm
  • Thursday – 9:15am – 2:15pm and 7pm – 10pm
  • Friday – 7pm – 10pm

Simply call our helpline on 08088 010 444, or email to book a time slot to speak with a nurse.



You can speak to our support team via WhatsApp on 07500068065.


They are available at the following times:

  • Monday – 9:00am – 5pm (excluding Bank Holidays in England)
  • Tuesday – 9:00am – 5pm
  • Wednesday – 9:00am – 5pm
  • Thursday – 9:00am – 5pm
  • Friday – 9:00am – 5pm

After 5pm on weekdays and throughout the weekend, our WhatsApp chats will not be monitored. We will strive to answer the messages received during these times on the next working day. The service will also be closed on England’s Bank Holidays.

If you require urgent advice, please call your medical team or ring 111. In an emergency, always ring 999.


You can also contact our Nurse Advisors via email at the following address: If outside of working hours, a nurse will aim to respond to your query the next working day, but this may take longer.


You can chat to one of our Nurse Advisors on our HealthUnlocked forum. Simply head to the forum website, register or sign in, and post your question in the forum. A nurse will then get back to you during working hours, or a member of our Patient Services team will answer your query when a nurse is unavailable. We also have a private Facebook group where those who have been affected by a blood cancer can chat. You can find this on Facebook by searching for “Leukaemia Care online support group”.

When our nurses are not available, we’re still here for you. Our Patient Services team and volunteers can provide a listening ear and answer your questions. You can contact them on the following services:


Our Patient Services team are also available on the helpline when our nurse is busy. You can talk to them at the following times:

  • Monday – Nurse available from 9am – 5pm
  • Tuesday – 2:15pm – 5:00pm
  • Wednesday – 2:15pm – 5:00pm
  • Thursday – 2:15pm – 5:00pm
  • Friday – 9am – 5:00pm

If you would like to speak to a nurse but one is not available, we will endeavour to book you a time slot for the nurse to call you back.


Our Patient Services team are available to answer your questions via WhatsApp, you can contact them on 07500068065.

They are available from 9am – 5pm. More information can be found here.

Blog post published on: 28th May 2021

Blog post last updated on: 12th August 2021

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