I have just finished a meeting I had with Pfizer (with several other patient groups) on the topic of their / BioNTech’s COVID vaccine and I am pleased to say that they gave us plenty of time for questions.
It was a fascinating session, and I hope to share some of the materials with you all soon. I need to get permission from Pfizer first, but they shared some great information about how the vaccine works.
Here's their response to my questions:
The vaccine is not a live vaccine. This was crucial to the MHRAs decision that the vaccine is safe for use in immunocompromised people or people taking immune suppressants. It is possible that it might not be fully effective in people with a low functioning immune system, but there is no safety concern.
Lots of people with stable autoimmune diseases were included in the trial, and also patients with stable HIV, and there has been no signal of any safety concerns in those groups.
Should bone marrow transplant patients, or patients with a splenectomy be treated any differently? Can they, or stem call transplant patients take this vaccine?
Similar to above – there is no safety concern for people with a bone marrow transplant, but the vaccine might not be fully effective.
Is there any way to determine if the vaccine has produced an immune response, maybe by way of a follow-up antibody test? Could immunocompromised people need a different dose?
The regime is for two doses – that is what is authorised, so larger or more doses for some patients will not be done as it hasn’t been studied.
Real-world observation studies will look at different patient groups, and compare things like rate of infection following vaccination. Basically this means that if over time it becomes clear that people taking a particular drug seem to catch COVID more, then it would be looked at in more detail.
Since pregnant women are advised not to take the vaccines, is there any longer term potential impact on fertility?
The vaccine is contraindicated in pregnant women because there were not enough of them in the trial – so this is being extremely cautious. It’s not that pregnant women had adverse effects.
Women should do their best to avoid getting pregnant within 2 months of vaccination. Studies are planned in pregnant women so they can ascertain if it is safe. Lastly there is no evidence whatsoever that there is any ongoing impact of fertility.
Other interesting topics that came up:
• They have strong mitigation plans in place in case of supply chain disruption caused by Brexit
• There are no egg or animal products in the vaccine
• Several reasons why they were able to run trials faster than usual, but still fully safe: Overlapping phase 1, 2, and 3 trials bought some time. The regulator (MHRA) took data on a rolling basis, as the trials went on rather than the usual method of waiting until the very end, and then start to analyse the data. Finally, a $2bn investment of producing the vaccine at scale and at commercial risk is unprecedented and allows much faster roll-out.