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________________________________________ From: Kenneth MacArthur
<[FOI #802905 email]> Sent: Thursday, October 28,
2021 9:04:50 PM To: MHRA Customer Services Subject: Freedom of Information
request - Antigenic imprinting following vaccination with Pfizer-BioNTech
COVID-19 vaccine (Comirnaty/tozinameran) Dear Medicines and Healthcare
products Regulatory Agency (MHRA), I am writing to make a request for
information under section 1 of the Freedom of Information Act 2000. Please
can you confirm whether the MHRA has considered the matter of the immune
system's response to infection with SARS-CoV-2 variants as a result of the
phenomenon of antigenic imprinting (AIM; also known as original antigenic
sin/antigenic sin/the Hoskins effect) following vaccination with the
Pfizer-BioNTech COVID-19 vaccine (Comirnaty/tozinameran). Further, if the
MHRA has considered the aforementioned matter, please can you provide any
information which the MHRA holds on this matter. I draw your attention to
the fact that, in your response to my request for internal review of the
FOI request 'Immune system's response to pathogens following COVID-19
vaccination'
(https://eur01.safelinks.protection.outlo...),
you stated that you would likely be able to handle a request framed as
above "expeditiously". Yours faithfully, Kenneth MacArthur
------------------------------------------------------------------- Please
use this email address for all replies to this request:
[FOI #802905 email] Is [MHRA request email] the wrong
address for Freedom of Information requests to Medicines and Healthcare
Products Regulatory Agency? If so, please contact us using this form:
https://eur01.safelinks.protection.outlo...
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show quoted sections

Our Ref: FOI 21/1183

Dear Kenneth MacArthur,

RE: REQUEST UNDER THE FREEDOM OF INFORMATION ACT 2000

Thank you for your enquiry which we received on 29th October 2021.

I confirm that your request is now being handled under the Freedom of Information Act and you should receive a reply within 20 working days from our date of receipt.

If you need to contact us again about this request, please quote the reference number above.

Please be aware that we publish FOIs replies and these are redacted and are located on our website at the following link below.
https://www.gov.uk/government/collection...

Kind Regards,

MHRA Customer Service Centre

Medicines and Healthcare products Regulatory Agency
10 South Colonnade, Canary Wharf, London E14 4PU
Telephone 0203 080 6000

show quoted sections

Dear Mr MacArthur

Regarding your email of 28 October 2021, where you asked whether MHRA can
confirm whether we have “considered the matter of the immune system's
response to infection with SARS-CoV-2 variants as a result of the
phenomenon of antigenic imprinting (AIM; also known as original antigenic
sin/antigenic sin/the Hoskins effect) following vaccination with the
Pfizer-BioNTech COVID-19 vaccine (Comirnaty/tozinameran).”

MHRA rigorously checks all data received for the Pfizer/BioNTech vaccine
for any adverse effects that could be related to that vaccine. To date,
MHRA have received no data that show that the phenomenon of antigenic
imprinting (also know as antigenic sin/Hoskin’s effect) exists following
administration of the Pfizer/BioNTech vaccine. As there is no evidence of
antigenic imprinting for MHRA to consider, we hold no further information
on this matter.

Best regards,

MHRA Customer Service Centre

Medicines and Healthcare products Regulatory Agency

10 South Colonnade, Canary Wharf, London E14 4PU

Telephone 0203 080 6000

[1]gov.uk/mhra

[2]Stay connected

For information on how the Agency uses your personal data and your data
protection rights, please see our three centres’ Privacy Notices: [3]MHRA,
[4]CPRD and [5]NIBSC.

show quoted sections