National guidance on face masks from April 2020 was drawn up by a group of experts from across the United Kingdom known as the IP (Infection Protection) Cell.
Its membership included representatives from the NHS, government departments and health bodies, including Public Health England (PHE), the organisation replaced by UKHSA in 2021 in a shake-up ordered by then-Health Secretary Matt Hancock.
The inquiry was shown minutes from an IP Cell meeting on 22 December 2020, just after the new Alpha variant of Covid had been detected, which appeared to show disagreement about the use of higher-grade FFP3 masks.
The records quote Dr Colin Brown, now the deputy director of clinical and emerging infections at UKHSA but at the time with PHE, as saying: “Our understanding of aerosol transmission has changed. A precautionary approach to move to FFP3 masks [in all healthcare settings] whilst we are awaiting evidence should be advised.”
However, the wider IP Cell decided that no upgrading of the guidance was warranted at the time, and NHS trusts were told to continue to supply staff with standard surgical masks in almost all cases outside intensive care.
It was not until January 2022 that the advice changed, saying that FFP3 respirators “must be worn” by all staff if they are caring for patients with a virus such as Covid, and should be offered to other staff depending on a risk assessment.
By that point, the World Health Organization, and other health bodies, had recognised Covid could be spread in tiny airborne particles over distances longer than 6.5ft (2m), something officials said was impossible at the start of the pandemic.
