Masks and respirators for prevention of respiratory infections: a state of the science review

Masks and respirators for prevention of respiratory infections: a state of the science review

SUMMARY This narrative review and meta-analysis summarizes a broad evidence base on the benefits—and also the practicalities, disbenefits, harms and personal, sociocultural and environmental impacts—of masks and masking. Our synthesis of evidence from over 100 published reviews and selected primary studies, including re-analyzing contested meta-analyses of key clinical trials, produced seven key findings. First, there is strong and consistent evidence for airborne transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and other respiratory pathogens. Second, masks are, if correctly and consistently worn, effective in reducing transmission of respiratory diseases and show a dose-response effect. Third, respirators are significantly more effective than medical or cloth masks. Fourth, mask mandates are, overall, effective in reducing community transmission of respiratory pathogens. Fifth, masks are important sociocultural symbols; non-adherence to masking is sometimes linked to political and ideological beliefs and to widely circulated mis- or disinformation. Sixth, while there is much evidence that masks are not generally harmful to the general population, masking may be relatively contraindicated in individuals with certain medical conditions, who may require exemption. Furthermore, certain groups (notably D/deaf people) are disadvantaged when others are masked. Finally, there are risks to the environment from single-use masks and respirators. We propose an agenda for future research, including improved characterization of the situations in which masking should be recommended or mandated; attention to comfort and acceptability; generalized and disability-focused communication support in settings where masks are worn; and development and testing of novel materials and designs for improved filtration, breathability, and environmental impact.

Low-cost measurement of face mask efficacy for filtering expelled droplets during speech

A simple method was developed for evaluating the efficacy of face masks to reduce respiratory droplet emission during speaking. , Mandates for mask use in public during the recent coronavirus disease 2019 (COVID-19) pandemic, worsened by global shortage of commercial supplies, have led to widespread use of homemade masks and mask alternatives. It is assumed that wearing such masks reduces the likelihood for an infected person to spread the disease, but many of these mask designs have not been tested in practice. We have demonstrated a simple optical measurement method to evaluate the efficacy of masks to reduce the transmission of respiratory droplets during regular speech. In proof-of-principle studies, we compared a variety of commonly available mask types and observed that some mask types approach the performance of standard surgical masks, while some mask alternatives, such as neck gaiters or bandanas, offer very little protection. Our measurement setup is inexpensive and can be built and operated by nonexperts, allowing for rapid evaluation of mask performance during speech, sneezing, or coughing.

Low-cost measurement of face mask efficacy for filtering expelled droplets during speech

A simple method was developed for evaluating the efficacy of face masks to reduce respiratory droplet emission during speaking. , Mandates for mask use in public during the recent coronavirus disease 2019 (COVID-19) pandemic, worsened by global shortage of commercial supplies, have led to widespread use of homemade masks and mask alternatives. It is assumed that wearing such masks reduces the likelihood for an infected person to spread the disease, but many of these mask designs have not been tested in practice. We have demonstrated a simple optical measurement method to evaluate the efficacy of masks to reduce the transmission of respiratory droplets during regular speech. In proof-of-principle studies, we compared a variety of commonly available mask types and observed that some mask types approach the performance of standard surgical masks, while some mask alternatives, such as neck gaiters or bandanas, offer very little protection. Our measurement setup is inexpensive and can be built and operated by nonexperts, allowing for rapid evaluation of mask performance during speech, sneezing, or coughing.

COVID-19 Vaccine Effectiveness and Safety for the 2026-2027 Respiratory Season

Importance SARS-CoV-2 remains a substantial cause of respiratory illness, morbidity, and mortality. Evidence to date has demonstrated that COVID-19 vaccines reduce the risk of severe disease, including hospitalization and death. Objective This systematic review identifies and summarizes newly published studies reporting on the effectiveness and safety of COVID-19 vaccines and COVID-19 epidemiology in the US. Evidence Review Cochrane Central Register of Controlled Trials, PubMed/MEDLINE, Embase, and Scopus were searched from August 1, 2025, through June 29, 2026. Studies were eligible if they reported on the effectiveness, efficacy, or safety of a US-licensed COVID-19 vaccine or SARS-CoV-2 epidemiology in the US. Findings From 11 829 identified references, 155 publications were eligible (15 randomized clinical trials, 84 observational studies with a comparator group, 38 product safety studies without a comparator group [single group], and 18 descriptive studies of disease burden). Consistent with prior evidence, studies reported that updated COVID-19 vaccines were associated with a reduction in the risk of hospitalization among both older adults (≥65 years; vaccine effectiveness [VE], 53.0%; 95% CI, 37.0%-65.0%; 2025-2026 season) and adults (18-64 years; VE, 54.0%; 95% CI, 1.0%-78.0%; 2024-2025 season). Maternal vaccination was associated with reduced risk of COVID-19–associated emergency department/urgent care encounters among individuals vaccinated (VE, 58.0%; 95% CI, 24.0%-77.0%) and with fewer COVID-19–related hospital contacts in the first 2 months of life among infants born subsequently (VE range, 50.0%-54.0%), regardless of trimester of vaccination. Vaccination was also associated with a significant reduction in COVID-19–related pediatric emergency department visits (9 months to 4 years; VE, 76.0%; 95% CI, 58.0%-87.0%). Vaccination was associated with a reduced risk of critical COVID-19 illness (intensive care unit admission or death) in immunocompromised adults (VE range, 32.0%-53.0%, depending on condition and other factors). Health care personnel who received 3 to 5 vaccine doses were less likely to develop laboratory-confirmed COVID-19 illness (VE, 41.0%; 95% CI, 34.0%-47.0%) and postacute COVID-19 symptoms (VE, 57.0%; 95% CI, 46.0%-66.0%) compared with those who received only 2 doses. Across adverse events of special interest (eg, stroke, thrombosis, myocarditis), safety profiles were consistent with those of previous reviews. No identified studies conducted under the updated guidance on extended dosing intervals for the primary series reported an increased risk of myocarditis or pericarditis. No new safety signals were reported in the recently published studies eligible for this updated review of US-licensed COVID-19 vaccines. Conclusions and Relevance COVID-19 vaccines were consistently associated with a reduction in the risk of hospitalization and other outcomes, including among individuals at high risk of severe COVID-19, such as infants, and those who were pregnant. No new safety concerns were identified.

COVID-19 Vaccine Effectiveness and Safety for the 2026-2027 Respiratory Season

This Special Communication aims to identify and summarize the most recently published evidence evaluating the effectiveness and safety of US-licensed COVID-19 vaccines and report on the epidemiology of SARS-CoV-2 in the US.

Inexpensive, Accessible Device Provides Visual Proof that Masks Block Droplets

DURHAM, N.C. – Duke physician Eric Westman was one of the first champions of masking as a means to curtail the spread of coronavirus, working with a local non-profit to provide free masks to at-risk and under-served populations in the greater Durham community.

Air Pollution Mask

Reusable urban air pollution mask with certified 99.99% PM2.5 filtration against traffic fumes, road dust and smog. Breathable, washable, built for daily city wear.

Environmental epidemiology in a crossfire

Two tendencies have emerged in environmental epidemiology that hamper the translation of research findings into prevention of environmental hazards. One is the increased focus on highlighting weaknesses of epidemiology research that is clearly meant to explain away the research conclusions and weaken their possible implications for interventions to control environmental hazards. Another is the voluminous amount of information sharing that involves a substantial amount of misinformation, as part of the ongoing infodemic. In this light, the appearance of the catalogue of doubt-raising strategies, indeed the worst practices of scientific inference, is good news. Collected under the auspices of the International Network for Epidemiology in Policy, it serves to illustrate the range of possible (and impossible) forms of critique that may be raised on behalf of vested interests or other groups who for some reason disagree with the epidemiological conclusions. We believe that this systematic list will be useful in our field and help to identify critiques of policy options that are hidden and sometimes suppressed in weighing the epidemiological evidence.

Severity of COVID-19 at elevated exposure to perfluorinated alkylates

Background The course of coronavirus disease 2019 (COVID-19) seems to be aggravated by air pollution, and some industrial chemicals, such as the perfluorinated alkylate substances (PFASs), are immunotoxic and may contribute to an association with disease severity. Methods From Danish biobanks, we obtained plasma samples from 323 subjects aged 30–70 years with known SARS-CoV-2 infection. The PFAS concentrations measured at the background exposures included five PFASs known to be immunotoxic. Register data was obtained to classify disease status, other health information, and demographic variables. We used ordered logistic regression analyses to determine associations between PFAS concentrations and disease outcome. Results Plasma-PFAS concentrations were higher in males, in subjects with Western European background, and tended to increase with age, but were not associated with the presence of chronic disease. Of the study population, 108 (33%) had not been hospitalized, and of those hospitalized, 53 (16%) had been in intensive care or were deceased. Among the five PFASs considered, perfluorobutanoic acid (PFBA) showed an unadjusted odds ratio (OR) of 2.19 (95% confidence interval, CI, 1.39–3.46) for increasing severities of the disease. Among those hospitalized, the fully adjusted OR for getting into intensive care or expiring was 5.18 (1.29, 20.72) when based on plasma samples obtained at the time of diagnosis or up to one week before. Conclusions Measures of individual exposures to immunotoxic PFASs included short-chain PFBA known to accumulate in the lungs. Elevated plasma-PFBA concentrations were associated with an increased risk of a more severe course of COVID-19. Given the low background exposure levels in this study, the role of exposure to PFASs in COVID-19 needs to be ascertained in populations with elevated exposures.

Airport air sampling captures COVID, influenza viruses

Researchers say air monitoring complements wastewater testing in detecting respiratory pathogens from diverse populations, including asymptomatic or pre-symptomatic people.

Neck Gaiters for COVID-19 Worse Than No Face Covering At All | Infection Control Today

Neck gaiters weren’t the only face coverings tested: in all 14 were analyzed, from N95s (unsurprisingly judged to be the most effective in containing COVID-19 spread) to bandanas (not much more effective then neck gaiters, according to the study).

Opposition in Japan to the Olympics during the COVID-19 pandemic

Little is known about the responses of citizens toward sporting mega-events held during a period of extended disasters, such as the 2020 Olympics held during the COVID-19 pandemic. This study aims to clarify the factors affecting citizens’ attitudes by testing the following hypotheses: the perception of high cost, the burden on medical institutions, and high risk of infectious disease spread negatively affect attitudes, while the perception of pandemic countermeasures, economic benefits, and athletes positively affect attitudes. Based on an online survey of 800 citizens before the 2020 Olympics, the hypotheses were tested using logistic regression models with the extracted factors as the explanatory variables and the attitude toward the Olympics as the objective variable. The test results confirm the factors lineated by the hypotheses, except for the perception of high cost. The fear of a healthcare system collapse from the medical burden of dealing with an outbreak has an especially strong negative effect on the attitude toward the Olympics. These results have important implications for city governments and municipalities and suggest that they should not underestimate citizens’ perceptions and attitudes when organizing mega-events and formulating proper communication. Further, the results may offer insights for the smooth strategic planning of large-scale events during unprecedented disasters.

Opposition in Japan to the Olympics during the COVID-19 pandemic

Little is known about the responses of citizens toward sporting mega-events held during a period of extended disasters, such as the 2020 Olympics held during the COVID-19 pandemic. This study aims to clarify the factors affecting citizens’ attitudes by testing the following hypotheses: the perception of high cost, the burden on medical institutions, and high risk of infectious disease spread negatively affect attitudes, while the perception of pandemic countermeasures, economic benefits, and athletes positively affect attitudes. Based on an online survey of 800 citizens before the 2020 Olympics, the hypotheses were tested using logistic regression models with the extracted factors as the explanatory variables and the attitude toward the Olympics as the objective variable. The test results confirm the factors lineated by the hypotheses, except for the perception of high cost. The fear of a healthcare system collapse from the medical burden of dealing with an outbreak has an especially strong negative effect on the attitude toward the Olympics. These results have important implications for city governments and municipalities and suggest that they should not underestimate citizens’ perceptions and attitudes when organizing mega-events and formulating proper communication. Further, the results may offer insights for the smooth strategic planning of large-scale events during unprecedented disasters.

The Mysterious Vaping Illness That’s ‘Becoming an Epidemic’ (Published 2019)

A surge of severe lung ailments has baffled doctors and public health experts.