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Behind the headlines: COVID-19 vaccine – an update

1st February 2021 // Caroline Donoghue

Since my last blog about the COVID-19 vaccine in November 2020, a lot has changed. Vaccine clinical trial results have been published in academic journals, and three vaccines have been approved for use in the UK.

It is clear from the approvals that the Pfizer/BioNTech vaccine, the Oxford/AstraZeneca vaccine and the Moderna vaccine are considered safe and effective for adults aged 16 and over.

The clinical trials have shown that the people who got a vaccine were less likely to get COVID-19 than the people who got a placebo. They have also shown that most of the side effects observed during the trials were mild and similar to other vaccines. They included a sore arm where the needle went in, feeling tired, a headache, feeling achy, feeling or being sick. More serious side effects like allergic reactions were very rare.

However, some myeloma patients are still unsure whether the vaccines are suitable for them. This is in part because there was a limited number of people with weakened immune systems (immunosuppressed or immunocompromised) in the trials.

So, how do we know the vaccines are suitable for myeloma patients?

Let’s start with effectiveness – how do we know the vaccines will be effective in myeloma patients?

To know this, we need to think about what vaccines do that protects people from infection.

The vaccines mimic COVID-19 and trick the immune system into making an immune response against COVID-19. This lets the body learn how to defend itself against COVID-19 which reduces the risk of infection. Therefore, to be effective the vaccine needs to trigger an immune response.

We know myeloma patients can trigger immune responses and fight infections. You may have your own data to support this if you have had a cold since your diagnosis. However, we also know the speed and level of immune response differ between patients depending on how well their immune system is functioning. For example, patients taking drugs which reduce the levels of immune cells (e.g. lymphocytes, neutrophils and leucocytes) will have reduced immune function and as a result lower immune responses. Therefore, the COVID-19 vaccine may not be fully effective in immunocompromised patients or people having immunosuppressing treatment.

We also know from previous research that other vaccines are effective in myeloma patients providing some protection against infection. However, the overall effectiveness of vaccines was less for myeloma patients.

So, the current science tells that the vaccines will work for myeloma patients and will provide some protection against COVID-19 – we just don’t know just how effective they will be.

Although the vaccine might not be fully effective in some myeloma patients, it is still important to be vaccinated as it will provide some protection against severe illness due to COVID-19.

Now, what about safety: how do we know that the vaccines are considered safe for myeloma patients? Again, this comes down to the science and how the vaccines work to trigger the immune response against COVID-19.

The Pfizer/BioNTech vaccine and the Moderna vaccines are mRNA vaccines and they use genetic material from COVID-19 to trigger an immune response. The genetic material is packaged into very small fat droplets. These droplets are absorbed by the body’s cells and trigger an immune response. The genetic material cannot make copies of itself or COVID-19. It doesn’t hang around in the body for long, as with other medicines, it is gradually broken down and removed from the body.

The Oxford-AstraZeneca vaccine is a viral vector vaccine and it also uses the genetic material from COVID-19 to trigger an immune response. However, in a viral vector vaccine, the genetic material is packaged in a harmless, weakened adenovirus (a type of cold virus). The modified adenovirus is absorbed by the body’s cells and triggers an immune response. It cannot make copies of itself or COVID-19. It doesn’t stay in your body indefinitely; it is gradually broken down and removed from the body.

Therefore, none of the approved vaccines contain ‘live’ COVID-19 virus, and so you can’t get COVID-19 from them – this means that they are don’t pose a greater risk to people with lower immune systems. As a result, the side effects for myeloma patients should be comparable to the side effect profile observed in clinical trials.

Naturally, people also want to know which of the vaccines is safest or most effective. At the moment, there are no comparative clinical trials so there is no data to assess which is more effective or which vaccine will last longest. Therefore, there is no evidence to suggest that one vaccine is better than other. They all give very high protection against severe illness due to COVID-19 and are considered safe for adults.

This why the current advice is that everyone, including myeloma patients, who is offered a vaccine, no matter which one is offered, should get it.

I mentioned earlier that some drugs lower the immune system and could affect how well the vaccine works. Therefore, myeloma patients who are on or awaiting treatment should speak to their haematologist when they receive their vaccination letter to check that the timing of their vaccination fits with their treatment schedule.

It is also important to note that no vaccine is 100% effective. As a result, everyone should continue to follow infection prevention measures, such as frequent hand washing and social distancing after vaccination to minimise their risk of infection.

Although the level of effectiveness in myeloma patients is not fully established, the evidence shows that it will offer some protection and has the potential to reduce the risk of severe illness due to COVID-19. To me, any protection against severe illness is amazing news and a much better option than no protection at all. Hopefully, myeloma patients across the UK will get their vaccination letters any day now if they haven’t already.