There is only “weak evidence” that high-grade face masks protect healthcare workers better than surgical masks in the pandemic, a Covid investigation has found.

Professor Susan Hopkins, chief medical adviser to the UK Health Protection Agency (UKHSA), said respiratory masks – known as FFP3 – may perform no better than thinner surgical masks in real-life situations.

He said wearing tight-fitting FFP3 could cause “significant harms” including blisters and difficulty breathing.

“If the evidence were strong that FFP3 actually protected people, and we saw a definite reduction (in infections), then they would have been recommended,” she said.

Not all scientists agree on what has become controversial.

BBC have previously reported on research Which appears to show significant real-world benefits from wearing high-grade masks on hospital wards.

During the first two years of the pandemic, groups representing doctors, nurses, and other health workers repeatedly called for immediate improvements in personal protective equipment (PPE), including widespread use of respirators.

FFP3s are tight-fitting masks with a built-in air filter designed to block small aerosol particles that may carry the virus.

Before use, each wearer must undergo a fit test to ensure that the mask is properly fitted to the face.

For most of the pandemic, national guidance across the UK stated that healthcare workers should wear basic surgical masks rather than FFP3, except in intensive care or certain medical situations.

Some staff at the doctors’ union, the BMA, heavily criticized the decision, describing it as “a matter of life and death”.

National guidance on face masks from April 2020 was drawn up by a group of experts in the United Kingdom known as the IPC (Infection Prevention and Control) Cell.

Its membership included representatives from the NHS, government departments and health bodies, including Public Health England (PHE), the organization was replaced by the UKHSA in 2021 on the orders of the then Health Secretary Matt Hancock.

The investigation showed minutes of the IPC cell meeting on December 22, 2020, when the new Alpha variant of Covid was detected, showed disagreements about the use of high-grade FFP3 masks.

The Record quotes Dr Colin Brown, now deputy director of clinical and emerging infections at the UKHSA but who was at PHE at the time, as saying: “Our understanding of aerosol transmission has changed. FFP3 masks (all “A precautionary approach to healthcare settings) should be advised while we wait for evidence.”

However, the wider IPC cell decided that no upgrades to the guidance were needed at that time, and NHS trusts were told to continue supplying staff with standard surgical masks in almost all cases outside intensive care.

This advice was not changed until January 2022, stating that FFP3 respirators should be available to “all relevant staff” based on risk assessment.

Until then, the World Health Organization and other health bodies had believed COVID could spread in small airborne particles more than 6.5 feet (2 meters), something officials said was unlikely at the beginning of the pandemic.

Professor Hopkins, who served as PHE’s chief Covid adviser before moving to the UKHSA, told the inquiry that FFP3 masks provided a high level of protection in laboratory studies, but the real-world benefits were less clear.

“Where we’ve seen it, and seen it repeatedly and are still seeing it, the evidence is weak that FFP3 provided more protection than fluid-resistant surgical masks,” he said.

“Initially, in March 2020, the risk was that we never asked people to wear FFP3 masks for long periods of time.

“We saw blisters on his face and he started having trouble breathing and staying hydrated.”

Asked about IP Cell minutes from December 2020, which suggested that PHE was working behind the scenes to push for the widespread use of respirator masks in health care, Professor Hopkins said this was “really difficult” in the pandemic. “challenging times” into which the UK was about to enter. Third wave of virus.

“The fact that PHE was giving and broadcasting a different viewpoint is an example of (our) not joining group think,” he said.

The Covid inquiry is currently taking evidence about the impact on the NHS and health care systems in all four countries of the UK.

More than 50 witnesses are expected to appear in this third section or “module”, which will run until the end of November.