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Behind the headlines: COVID-19 vaccine effectiveness in cancer patients

12th March 2021 // Caroline Donoghue

This week, results from a study measuring the effectiveness of the Pfizer-BioNTech COVID-19 vaccine in cancer patients has been in the news. The news reports discussing the study have claimed that cancer patients get ‘less protection’ from the vaccine than non-cancer patients.

However, as we often find with research, especially with early results, the conclusions that can be drawn from the data are less definitive than the news reports.

What does this study mean for myeloma patients?

Whilst this study supports our concerns about how well myeloma patients respond to the vaccine it doesn’t change our advice for patients.

Patients should get BOTH doses of the vaccine when they are offered. This is because the study didn’t raise any safety concerns and it showed that the vaccine could give some protection against COVID-19, particularly after the second dose.

Patients should take the vaccine they are offered whether it is the Pfizer-BioNTech or the Oxford-AstraZeneca vaccine. There is no evidence to confirm if one vaccine is better than the other for any specific group of people. Both provide protection against COVID-19.

Everyone, even non-myeloma patients, should continue to follow infection prevention measures, such as frequent hand washing and social distancing after vaccination to minimise their risk of infection. No vaccine is 100% effective and the data around transmission is limited so there is still a risk of developing or spreading COVID-19 after vaccination.

Nevertheless, the study does give us more information about how cancer patients respond to the Pfizer-BioNTech vaccine and highlights the need for more research in this space.

What the study tells us about response to the first dose

To understand exactly what the study tells us we need to look at the study design – who joined the study and what was being measured.

The study included a small, mixed group of people. There were 54 healthy people without cancer- the control group – and 151 people with cancer. The cancer group included patients with different types of cancer and people taking various cancer treatments as well as people off treatment. Only 56 participants had a type of blood cancer and the number of myeloma patients was not reported. Therefore, whilst this study gives us an indication of how cancer patients respond to the vaccine it can’t confirm how myeloma patients respond.

The study didn’t measure protection against COVID-19, it measured immune response to the first and second doses of the vaccine. Immune response was measured in two main ways – the presence of vaccine specific antibodies (antibody response) and the presence of activated T-cells, a type of immune cell (T-cell response). This is because antibody production and T-cell activation are key ways we know our bodies fight viral infections.

After one dose of the vaccine, antibody response was seen in 97% of the control group, 39% of the non-blood cancer group, and 13% in the blood cancer group. T cell response was not measured in every participant. Of those tested, T-cell response was seen in 82% of the control group, 71% in the non-blood cancer group, and 50% in the blood cancer group. This shows that at least 50%, maybe more, had some sort of immune response to vaccination. This suggests that cancer patients are less likely to produce an antibody or T-cell response to the first dose of the vaccine and therefore may not be as well protected against COVID-19.

The data did not include information about the number of COVID-19 cases, so it can’t tell us if the vaccine reduces the risk of infection or the risk of severe infection. This is why it tells us about the response to the vaccine, not about protection against COVID-19 infection.

Pfizer-BioNTech vs Oxford-AstraZeneca

Because this study started at the beginning of the vaccination programme it only includes patients who received the Pfizer-BioNTech vaccine, so the results only refer to the Pfizer-BioNTech vaccine. No data about the immune response to the Oxford-AstraZeneca vaccine has been released so there is no way to tell if immune responses in cancer patients would be the same, worse, or better. Therefore, this data doesn’t mean cancer patients should not get the Pfizer-BioNTech vaccine.

What the study tells us about response to the second dose

Although, limited study participants received the second dose three weeks after the first dose the data shows that immune responses increased in both the control and cancer patient groups. This further highlights the importance of the second dose.

As a result, this study has raised some questions about the timing of the second Pfizer-BioNTech dose. It didn’t measure if there was a difference in the immune response to the second dose if it was given at three weeks or 12 weeks. So, the best timing for the second dose is still unknown.

However, the Joint Committee on Vaccination and Immunisation’s (JCVI) recommendation to increase the dosing schedule for the Pfizer-BioNTech dose for three to 12 weeks was partly based on the immune response data in the clinical trials. This immune response data helped provide reassurance that the first dose of vaccine gave enough protection to justify prioritisation of first doses in all priority groups rather than prioritising the second doses in vulnerable patient groups. Because this study raises concerns about how well the clinical trial data represents cancer patients there is an argument for further assessment of the patient data to ensure that cancer patients get the second dose at the most appropriate time.

If you are concerned about the length of time between doses speak to your healthcare team. There is some flexibility in the dosing schedule for both vaccines to allow doses to be given closer together, especially where there is a clear patient benefit.

Overall, this study does tell us more about how cancer patients respond to the Pfizer-BioNTech vaccine, but it doesn’t answer all our questions and doesn’t really provide the information the myeloma community needs. We will continue to push for more data in the space to ensure myeloma patients get the right protection against COVID-19. One of the ways we are doing this is by partnering with leading blood cancer researchers and other leading blood cancer charities as part of the Blood Cancer Vaccine Taskforce.

Try not to be disheartened by this news. We are making progress as with every study we learn more, and with every vaccination the UK becomes further protected against COVID-19.

 

If you are worried about this news or have any questions, please get in touch with our Myeloma Infoline Specialists on 0800 980 3332 or askthenurse@myeloma.org.uk