<do you think it was 'good' for fauci to conflate science with politics, when persuading folks to
not use masks last year?.
I think Fauci was scientifically correct earlier and became politically correct later, at least for one side of the politics. Now if you want to anecdotally believe that masks for everyone reduces overall community spread, that is a decent hypothesis and a worthwhile experiment. But I have not spotted scientifically rigorous studies related to that. If you find any please post here.
I think the layperson has too much expectation of science. They want simple answers. And they want too much security. It is clear that masks do not prevent transmission fully. You are not going to be completely safe just with a mask, unless it is a super mask.
It was known from the previous SARs episodes that only extreme masking may significantly prevent infection.
ncbi.nlm.nih.gov
Extreme masking was not available in March 2020. It was barely available to a few doctors and nurses. And ordinary people would not use them perfectly anyway. As far as I remember, Fauci did qualify by saying that masks need to be left for medical staff.
In the absence of sufficient masks, other measures like social distancing, disinfecting, and hand washing are standard practices that slow down infection. And Fauci pointed that out.
Here is another face mask study from 2010 which was kind of inconclusive:
cambridge.org
In conclusion there remains a substantial gap in the scientific literature on the effectiveness of face masks to reduce transmission of influenza virus infection. While there is some experimental evidence that masks should be able to reduce infectiousness under controlled conditions [ 7], there is less evidence on whether this translates to effectiveness in natural settings. There is little evidence to support the effectiveness of face masks to reduce the risk of infection. Current research has several limitations including underpowered samples, limited generalizability, narrow intervention targeting and inconsistent testing protocols, different laboratory methods, and case definitions. Further in-vivo studies of face masks in infectious individuals are warranted to determine the proportion of exhaled virus that is trapped by the mask. More detailed volunteer challenge and volunteer transmission studies could be designed to include both infectious and susceptible participants, to evaluate the efficacy of face masks both in reducing infectiousness and reducing susceptibility. However, such studies would require substantial resources, and contrived experiments may have limited generalizability to the natural setting. Large intervention studies in healthcare and community settings are likely to provide the best evidence of the effectiveness of face masks in reducing transmission in pandemic and inter-pandemic periods and are an urgent priority to guide pandemic preparedness for second and subsequent waves of pandemic influenza A (H1N1) and future pandemics.
Here is another from NIH in 2012
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5779801/
In conclusion, there is a limited evidence base to support the use of masks and/or respirators in healthcare or community settings. Mask use is best undertaken as part of a package of personal protection, especially including hand hygiene in both home and healthcare settings. Early initiation and correct and consistent wearing of masks/respirators may improve their effectiveness. However, this remains a major challenge – both in the context of a formal study and in everyday practice.
Continued research on the effectiveness masks/respirators use and other closely associated considerations remains an urgent priority with emphasis being on carefully designed observational studies and trials best conducted outside a crisis situation. 35 However, examination of the literature has highlighted that well-designed studies in this field are challenging. 27 Studies need to be adequately powered to assess potentially small differences between interventions and the independent effect of mask/respirator wearing when a second intervention (e.g. hand hygiene) is employed; an appropriate control group must be identified (e.g. no use of masks/respirators). Most of the studies we examined were too small to reliably detect what would be anticipated to be moderate effects. Perhaps, one solution is to fund large multi-centre trials with similar protocols in different sites for multiple years to achieve sufficient power. Protocols should include the collection of detailed exposure data, objective monitoring of compliance and assessment of potential confounders. It may be difficult to design studies employing a control group that does not use any protective equipment (including masks/respirators), particularly in healthcare settings, as such precautions are routinely recommended. Finally, there is a striking paucity of published studies with microbiologically proven influenza infection as an outcome; inclusion of laboratory outcomes is essential in any future study of masks/respirators on transmission of influenza.
This study from 2019 says not much difference between N95 and regular. Both are equally good or bad.
sciencedaily.com
he new study was performed at multiple medical settings in seven cities around the country, including Houston, Denver, Washington, and New York, by researchers at the University of Texas, the CDC, Johns Hopkins University, the University of Colorado, Children's Hospital Colorado, the University of Massachusetts, the University of Florida, and several Department of Veterans Affairs hospitals. Researchers collected data during four flu seasons between 2011 and 2015, examining the incidence of flu and acute respiratory illnesses in the almost 2,400 health care workers who completed the study.
The project was funded by the CDC, the Veterans Health Administration, and the Biomedical Advanced Research and Development Authority (BARDA), which is part of the U.S. Health and Human Services Department and was founded in the years after Sept. 11, 2001, to help secure the nation against biological and other threats.
"It was a huge and important study -- the largest ever done on this issue in North America," Dr. Perl said.
In the end, 207 laboratory-confirmed influenza infections occurred in the N95 groups versus 193 among medical mask wearers, according to the report. In addition, there were 2,734 cases of influenza-like symptoms, laboratory-confirmed respiratory illnesses, and acute or laboratory-detected respiratory infections (where the worker may not have felt ill) in the N95 groups, compared with 3,039 such events among medical mask wearers.
"The takeaway is that this study shows one type of protective equipment is not superior to the other," she said. "Facilities have several options to provide protection to their staff -- which include surgical masks -- and can feel that staff are protected from seasonal influenza. Our study supports that in the outpatient setting there was no difference between the tested protections."
|
