Masks make ‘little or no difference’ in covid infections, massive study finds

Masks made ‘little or no difference’ in Covid infection or death rates, according to one of the most comprehensive meta-analyses of face coverings.

The investigation – carried out by the Cochrane Institutethe “gold standard” of evidence-based reviews, it looked at 78 global studies involving more than a million people.

The results indicated that surgical masks reduced the risk of contracting ‘Covid or a flu-like illness’ by only five per cent, a figure so low that it may not be statistically significant.

The researchers said the harms caused by masks, including hindering children’s schooling, were poorly measured in studies, meaning any small benefit in infection rates may be outweighed.

Professor Francois Balloux, professor of computational biology at University College London, who was not part of the analysis, said it showed that the benefit of wearing masks is “small at best”.

While initially considered a virus prevention measure, masks have become a prominent symbol of the Covid culture wars in the US.

Officials issued mixed messages about its effectiveness at the start of the pandemic. Studies that came later could not definitively prove that masks prevented Covid, yet millions of Americans were forced to comply with the mandates.

Some of the researchers involved in the Cochrane review previously reviewed the evidence on face masks in November 2020.

That review was criticized because it did not include any studies of the Covid pandemic due to limited research at the time.

A separate Danish study in spring 2020 with more than 6,000 participants found that wearing a mask made no statistical difference in whether or not people contracted Covid. But its researchers struggled to find a prominent journal willing to publish the results.

Cochrane researchers updated their review with an additional 11 studies involving more than 600,000 people, bringing the total number of studies to 78. The analysis was published this week in the journal Cochrane Database of Systematic Reviews daily.

Some of the additional studies looked at covid, while others were done before the pandemic and looked at flu and other respiratory illnesses.

They included covid pandemic trials: two from Mexico and one each from England, Norway and Bangladesh, in addition to the Danish study.

The researchers only added randomized controlled trials ( RCTs ) that looked at the effect of physical interventions to protect against disease, including the use of masks.

RCTs are the optimal method to avoid systematic differences between participants affecting the results. In RCT studies, the mask and control groups are randomly chosen from the same eligible population.

The main outcomes that the Cochrane researchers measured were the number of cases of influenza-like illness and covid-19 and any adverse events arising from the intervention.

Cochrane researchers calculated risk ratios related to mask use.

A value less than one indicates that the intervention improved the outcome and a value greater than one indicates that it worsened it. The closer the risk ratio value is to one, the smaller the effect it has.

The researchers noted a high risk of bias in the studies and “relatively low adherence to interventions”, making it difficult to draw firm conclusions.

But Professor Balloux tweeted: ‘Cochrane reviews are the ‘gold standard’ in evidence-based medicine.

“They follow a rigorous methodology and only consider high-quality evidence. As such, the review included a limited number of studies and is moderately powered to detect small effects.

“Regardless of the limitations of the study, their results indicate that the true impact of medical/surgical masks and N95/P2 respirators on the transmission of respiratory viruses is small at best.”

To compare the effect of masks in preventing the spread of covid and flu, Cochrane researchers analyzed 12 trials: two in healthcare workers and 10 in the community.

They found that in the community, wearing a face mask reduced the risk of contracting the flu or a covid-like illness by five percent.

The study suggested that there is actually a one per cent increased risk of testing positive if you wear a mask, but the margins are too small to say for sure.

The team said both results were “moderate-certainty evidence.”

They also looked at the effect of higher-quality masks, such as N95s, compared to standard surgical masks, but were less certain of its impact.

The CDC only recommended that people wear N95s two years into the pandemic.

This part of the analysis looked at five studies, four in health workers and one in households, with a total of 16,000 participants.

They found that wearing a mask reduced the chances of clinical respiratory illness by 30 percent.

But Professor Carl Heneghan of Oxford University, who was not listed as the paper’s authors, recognized that “harms were rarely measured and poorly reported”, meaning it was “very low-certainty evidence”.

N95 masks are even more uncomfortable than surgical masks due to their thick material and tight fit.

Nurses who wore them for long periods of time during the pandemic have reported cuts and scars on their faces as a result.

But this also makes them better at preventing infection than regular surgical masks, which are too porous to block the passage of microscopic viral particles.

The debate over masks first soured in 2020 when health officials changed their effectiveness.

Then-NIAID director Dr. Anthony Fauci said in 2020 that masks “didn’t provide the perfect protection that people think it is.”

He later suggested that people should wear masks as a sign of “respect” for others, admitting to lying to the public about the effectiveness of masks in order to prevent panic buying and preserve masks for healthcare workers.

The CDC website currently states that masks can help protect the wearer and others from Covid.

The agency continues to recommend that Americans wear masks in places with high levels of transmission, such as on public transportation.

Critics of the masks claim they have hampered communication and children’s development and progress at school.

The increases in RSV and flu this winter were partly attributed to face covering mandates because they prevented children from gaining natural immunity against other diseases.