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Cheap ways to starve a virus: Masks reduce spread by 70%, Distance by 80%

Posted By Jo Nova On July 1, 2020 @ 1:40 am In Global Warming | Comments Disabled

One good thing about Coronavirus is that people are suddenly paying attention to all the cheap easy ways to slow viruses. Hopefully we will get a bit better at preventing other respiratory infections too. 

As I’ve mentioned before, masks stop as much as 75% of influenza, and now we know the number is similar with Coronavirus. If any drug was this effective, it would be hailed as a Gamechanging Breakthrough (!).

Indeed, just yesterday Anthony Fauci said he’d settle for 70%, 75% effective vaccine, but masks are here already. And we don’t have to wear them forever, just til we starve the virus, set up border checks, and get the cases to zero. Then we wait for a long term solution. 2020 is going to be the year of the mask.

With Coronavirus cases ramping up again all over the world, people like Mike Pence, and Australia’s Health Minister are talking about them. If we add Vitamin D at 5c a dose (which can reduce the spread of influenza by 40%) perhaps some states could avoid a repeat mass lockdown?

Given the cost in deaths and dollars of the spread of this virus, it would be cheaper to give out free masks, free glasses and a years supply of Vitamin D for whole nations than to lockdown for one week. Even if a lockdown is necessary, masks and social distancing would shorten it. What’s not to like?

As with all counter-virus measures, there are no guarantees, but masks protect both the wearer and protect those around them. In regions with free-range viruses, the sooner masks and distancing are started, the better.


 Metastudy shows masks and distance helps

A review study pooled 172 studies with 25,697 participants. They looked at whether distancing or masks reduce the spread of Coronavirus, or SARS or MERS. Most were in healthcare settings, unfortunately none were randomized.

Remarkably, surgical masks reduced the odds of getting infected from 17% down to 3%. N95 “respirator” masks were even more effective. The lower grade surgical masks reduced the odds by 78%, but the N95 masks reduced that to 95%. Distancing was also useful. Even being more than 1 meter apart reduced the odds from 12.8% down to 2.6%.

Eye protection may also prevent 60% of infections.

Masks, distancing, eye protection, effectiveness, covid-19

Best available evidence supports physical distancing and wearing face masks

Medical News Today

The authors found good evidence that both face masks and eye masks significantly reduced transmission of the virus for health care workers and people working in the community, such as care home workers.

The odds of developing an infection with a coronavirus were reduced by 78% when wearing any mask, compared with the odds of infection when not wearing a mask. When using masks that conform to the N95 standard, this figure increased to 96%.

According to co-lead study author Dr. Holger Schünemann, who, like Dr. Chu, works at McMaster University, in Ontario, Canada, “Although the direct evidence is limited, the use of masks in the community provides protection, and possibly N95 or similar respirators worn by healthcare workers suggest greater protection than other face masks.”

 Some of the error bars are wide, but the message is consistent. Masks = lower spread.

People who are not trained won’t find them as useful. (So let’s train people).

Chu, Masks, Coronavirus.

We are so lucky Coronavirus is not measles. Even I am surprised that a 1 meter distance was useful.

If you really want to avoid it a three meter distance is probably much better.

The authors conclude that there is good evidence that maintaining a minimum distance of 1 meter, or about 3.3 feet, from other people is likely to have a significant effect on reducing the spread of the virus.

Across 38 studies that included information about distancing, infection rates overall were reduced to 2.6% when maintaining a distance of more than 1 meter from a person with the infection. By comparison, among studies in which distancing was less than 1 meter, the infection rate was 12.8%.

Furthermore, the authors found evidence that increasing the distance to 2 meters was likely to have an even greater effect.

 In the graph below distancing helps reduce the spread.

Masks, Effectiveness, Graph, Lancet, Coronavirua, metastudy, review

Review | Click to enlarge

Eye protection may prevent 60% of infections, hard to say:

Thirteen studies (across all three viruses, including 3,713 participants) focusing on eye protection found that face shields, goggles, and glasses were associated with lower risk of infection, compared with no eye covering (risk of infection or transmission when wearing eye protection was 6% vs 16% when not wearing eye protection). The authors note that the certainty of the evidence for eye coverings is low [1].

Still no non-randomized study, nor big study outside the hospital setting?

Amazing what we don’t know. Here we are with 10 million cases, and half a million deaths, and one hundred years of influenza, and yet we still don’t have top notch, mass randomized and solid studies.

That said, spare a thought for researchers — just yesterday Medpage discussed why so many single point studies in coronavirus had failed – they barely got time to raise funds and start enrolling patients when the wave moved to another hospital.

Handy things to know about masks:



Chu et al (2020) Physical distancing, face masks, and eye protection to prevent person-to-person transmission of SARS-CoV-2 and COVID-19: a systematic review and meta-analysis, www.thelancet.com Vol 395 June 27, 2020, http://dx.doi.org/10.1016/S0140-6736(20)31142-9 

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