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Why am I being invited for another Covid vaccine? - Third doses and boosters

30th Nov 2021 - Rachel Kahn

On the 29th November 2021, the JCVI announced that all people who are immunocompromised, which includes those with blood cancer, are now eligible for a booster (fourth dose) of the Covid vaccine, to be given three months after their third primary dose. In this blog, we explain more.

This blog was published on 30 November 2021. Read our more recent information about booking your third dose and booster (fourth dose) of the covid vaccine.

While we welcome this news, we understand that this announcement has caused a lot of confusion. The vaccine roll-out over the last few months has been far from ideal for people with blood cancer, and many have struggled to access their third primary dose. This has understandably caused frustration and this new announcement has added to the confusion. We hope this blog clears up some of this confusion, and for anything we don’t yet know, we want to reassure you that we are seeking clarification.

Are the third dose and the booster the same thing?

No. It was announced on the 29th November that people with blood cancer are eligible to receive both a third primary dose of the Covid vaccine and a booster dose three months after the third dose. Blood cancer affects how our immune systems work and so is likely to reduce the effectiveness of vaccines. This is why back in September, the JCVI said that people with blood cancer should have a third primary dose, as they were less likely to get a strong immune response to just two doses. A booster dose (a fourth dose) on top of this aims to boost the response even further.

What does this mean for me?

For those who have already had the first three primary doses of the Covid vaccine, this means you will now be eligible for a booster vaccine, three months after your third dose. This will be a half dose of the Moderna vaccine or a full dose of the Pfizer vaccine. We are currently seeking clarification from the NHS on how you can book your booster and will update you as and when we know more.

For those who have not yet been able to access their third primary dose, if you live in England you should now be able to book your third primary vaccine dose via the NHS website (but you'll need a letter from your doctor to take to your vaccine appointment). For instructions on how to get this letter from your doctor, and for information about getting your third dose in Scotland, Wales or Northern Ireland, see our information about how to book your third dose. If you receive the Moderna vaccine as your third vaccine, this should be given as a full dose.

Why am now being asked to have another vaccine so soon after the third?

For people without blood cancer, the JCVI had said that they should receive a booster vaccine 6 months after their previous dose. However, this has now been brought forward for everyone to 3 months. Part of this is due to the emergence of the new variant of concern Omicron. There are several unanswered questions about this variant. We don’t yet know if it’s more infectious and we don’t know how it might affect vaccine effectiveness. What we do know is that vaccination is the best way to try and protect ourselves if Omicron does prove to be more infectious. This is why the JCVI have bought the booster doses forward for everyone.

As well as this, you want to have an optimum immune response to Covid during the upcoming cold winter months, when rates of infection are likely to be highest, rather than in the Summer when the weather is likely to mean rates are lower. We know antibody response to vaccination can start to wane fairly quickly and therefore we want people to have as much protection as possible at a time when the rates are likely to be highest.

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My third dose was put on the system as a booster, does this still mean I can get a booster?

Yes. You can get a booster but we’re unsure at the moment exactly how this will work and we are seeking clarification on this from the NHS. We were previously told that if your third dose had been recorded as a booster, it would be retrospectively re-coded as a third dose, but we don’t know where the NHS are with this at the moment. We also don’t yet know how people will book their booster but we will update you as and when we know more.

I wasn’t able to book a third dose, so I had a booster. Can I still get another vaccine?

Yes. If you have blood cancer you are still eligible for a booster even if your third vaccine was technically booked as a “booster”. We have seen an increase in awareness among healthcare professionals around which of their patients are eligible for three primary doses and a booster, and so hope some of the previous challenges with booking vaccines will be reduced. However, we are unsure on the logistics of the roll-out at this stage and will update you when we know more.

I have no antibodies after three vaccine doses. Why should I get another?

It’s really important you get your booster when you’re eligible. Antibodies are only one measure of vaccine effectiveness. It’s the cheapest and easiest way to look at whether someone has had an immune response, which is why we do these tests, but we have a whole armour of immune cells which respond to the vaccine and provide protection from Covid. If you have no antibodies after three doses, you may still have T cells, and a booster dose could increase the number of these valuable cells. In addition to this, we know from research that the number of people developing antibodies increases as they have more doses. One study found that while a majority of people with blood cancer had no antibody response after two vaccine doses, over half of these people developed antibodies after a third dose. There is good reason to believe that antibody response will be improved even more after a booster. But remember - antibodies aren't the only measure of protection from Covid.

We hope this has cleared up some of the questions you have on the booster vaccines. We will keep you updated as and when we know more, and you can contact our support service if you have any questions or concerns.

For more information see these other important pages:

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