Public Accountability Unit
T 020 8327 6920
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London SE1 8UG
www.gov.uk/phe
By email
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Our ref: 28/02/hf/2927
25 March 2021
Dear Chris Moffett
Re: Asymptomatic Transmission of Sars Cov 2 and isolation
Thank you for your request received on 28 February 2021 addressed to Public
Health England (PHE). In accordance with Section 1(1)(a) of the Freedom of
Information Act 2000 (the Act), I can confirm that PHE partly holds the information
you have specified. I have answered your questions in turn.
Request
The attached article form the BMJ states "The transmission rates to contacts
within a specific group (secondary attack rate) may be 3-25 times lower for
people who are asymptomatic than for those with symptoms.1121415 A city-
wide prevalence study of almost 10 million people in Wuhan found no
evidence of asymptomatic transmission".
https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.bm
j.com%2Fcontent%2F371%2Fbmj.m4851%3Ffbclid%3DIwAR0OzG3rYtZYC9IJE
cJULGBTU6OGJcccHVIkhxAyqLn0d_IoAjqMJH-
7prc&data=04%7C01%7CFOI%40phe.gov.uk%7Ca2faa9983f8b493d8cac08
d8dbfc80fd%7Cee4e14994a354b2ead475f3cf9de8666%7C0%7C0%7C63750122
5588653221%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIj
oiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=%2FSq
%2BhV%2F%2FYPVPIeFrCG15uJcizMV499uEoGyKn8jTnX0%3D&reserve
d=0
1. What is the evidence -ie scientific papers/reports- being used by our
government to demonstrate that asymptomatic transmission of Sars Cov 2 is
at a dangerous level?
PHE can confirm that it does not hold the information in the way you have specified.
Under Section 16 of the Act, public authorities have a duty to provide advice and
assistance. Accordingly, I have provided the following link to scientific evidence
supporting the Government response to COVID-19, including that in relation to
asymptomatic transmission:
https://www.gov.uk/government/collections/scientific-evidence-supporting-the-
government-response-to-coronavirus-covid-19 Furthermore, you may wish to review the Scientific Advisory Group for Emergencies
(SAGE) meeting minutes and supporting papers available at the above link.
2. What evidence is there that the Sars Cov 2 virus has been isolated?
PHE can confirm it does hold information on the isolation of SARS-CoV-2, meaning
culture in a laboratory. The term “isolation” is used sometimes interchangeably to
mean isolation from a patient or clinical material – but usually implies that the
organism has been grown in culture. An organism is identified by looking for its
unique genetic material in a clinical sample and further identification is refined and
confirmed by whole genome sequencing.
The Virus Reference Laboratory at PHE, Colindale, London has grown the virus,
SARS-CoV-2. The virus culture method has been published in the following peer-
reviewed pape
r: https://www.eurosurveillance.org/content/10.2807/1560-
7917.ES.2020.25.32.2001483 If you have any queries regarding the information that has been supplied to you,
please refer your query to me in writing in the first instance. If you remain dissatisfied
and would like to request an internal review, then please contact us at the address
above or by emailing
xxx@xxx.xxx.xx. Please note that you have the right to an independent review by the Information
Commissioner’s Office if a complaint cannot be resolved through the PHE
complaints procedure. The Information Commissioner’s Office can be contacted by
calling the ICO’s helpline on 0303 123 1113, visiting the ICO’s website at
www.ico.org.uk or writing to the ICO at Wycliffe House, Water Lane, Wilmslow,
Cheshire, SK9 5AF.
Yours sincerely
FOI Team
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