Prevent Coronavirus Disease Research Articles

American Association for the Study of Liver Diseases Expert Panel Consensus Statement: Vaccines to Prevent Coronavirus Disease 2019 Infection in Patients With Liver Disease.

The aim of this document is to provide a concise scientific review of the currently available COVID‐19 vaccines and those in development, including mRNA, adenoviral vectors, and recombinant protein approaches. The anticipated use of COVID‐19 vaccines in patients with chronic liver disease (CLD) and liver transplant (LT) recipients is reviewed and practical guidance is provided for health care providers involved in the care of patients with liver disease and LT about vaccine prioritization and administration. The Pfizer and Moderna mRNA COVID‐19 vaccines are associated with a 94%‐95% vaccine efficacy compared to placebo against COVID‐19. Local site reactions of pain and tenderness were reported in 70%‐90% of clinical trial participants, and systemic reactions of fever and fatigue were reported in 40%‐70% of participants, but these reactions were generally mild and self‐limited and occurred more frequently in younger persons. Severe hypersensitivity reactions related to the mRNA COVID‐19 vaccines are rare and more commonly observed in women and persons with a history of previous drug reactions for unclear reasons. Because patients with advanced liver disease and immunosuppressed patients were excluded from the vaccine licensing trials, additional data regarding the safety and efficacy of COVID‐19 vaccines are eagerly awaited in these and other subgroups. Remarkably safe and highly effective mRNA COVID‐19 vaccines are now available for widespread use and should be given to all adult patients with CLD and LT recipients. The online companion document located at https://www.aasld.org/about‐aasld/covid‐19‐resources will be updated as additional data become available regarding the safety and efficacy of other COVID‐19 vaccines in development.

Whole-Genome Sequencing of SARS-CoV-2 from Quarantine Hotel Outbreak

Hotel quarantine for international travelers has been used to prevent coronavirus disease spread into Australia. A quarantine hotel–associated community outbreak was detected in South Australia. Real-time genomic sequencing enabled rapid confirmation tracking the outbreak to a recently returned traveler and linked 2 cases of infection in travelers at the same facility.

Delayed cutaneous reactions after the administration of mRNA vaccines against COVID-19

Vaccination is an effective intervention to prevent coronavirus disease 2019 (COVID-19). Two mRNA vaccines, Comirnaty (BioNTech, Mainz, Germany; Pfizer, New York City, NY)1 and COVID-19 Vaccine Moderna (ModernaTX, Inc, Cambridge, Mass),2 are approved for mass administration.

Developing Acid-Responsive Glyco-Nanoplatform Based Vaccines for Enhanced Cytotoxic T-lymphocyte Responses Against Cancer and SARS-CoV-2.

Cytotoxic T‐lymphocytes (CTLs) are central for eliciting protective immunity against malignancies and infectious diseases. Here, for the first time, partially oxidized acetalated dextran nanoparticles (Ox‐AcDEX NPs) with an average diameter of 100 nm are fabricated as a general platform for vaccine delivery. To develop effective anticancer vaccines, Ox‐AcDEX NPs are conjugated with a representative CTL peptide epitope (CTLp) from human mucin‐1 (MUC1) with the sequence of TSAPDTRPAP (referred to as Mp1) and an immune‐enhancing adjuvant R837 (referred to as R) via imine bond formation affording AcDEX‐(imine)‐Mp1‐R NPs. Administration of AcDEX‐(imine)‐Mp1‐R NPs results in robust and long‐lasting anti‐MUC1 CTL immune responses, which provides mice with superior protection from the tumor. To verify its universality, this nanoplatform is also exploited to deliver epitopes from severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) to prevent coronavirus disease 2019 (COVID‐19). By conjugating Ox‐AcDEX NPs with the potential CTL epitope of SARS‐CoV‐2 (referred to as Sp) and R837, AcDEX‐(imine)‐Sp‐R NPs are fabricated for anti‐SARS‐CoV‐2 vaccine candidates. Several epitopes potentially contributing to the induction of potent and protective anti‐SARS‐CoV‐2 CTL responses are examined and discussed. Collectively, these findings shed light on the universal use of Ox‐AcDEX NPs to deliver both tumor‐associated and virus‐associated epitopes.

Impaired Antibody Response to the BNT162b2 Messenger RNA Coronavirus Disease 2019 Vaccine in Patients With Systemic Lupus Erythematosus and Rheumatoid Arthritis.

ObjectiveWith a vaccine effectiveness of 95% for preventing coronavirus disease 2019 (COVID‐19), Pfizer‐BioNTech BNT162b2 (BNT162b2) was the first vaccine against severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) to be approved. However, immunosuppressive therapy was an exclusion criterion in the phase 3 trial that led to approval. Thus, extrapolation of the trial results to patients with rheumatic diseases treated with immunosuppressive drugs warrants caution.MethodsPatients with systemic lupus erythematosus (SLE; n = 61) and rheumatoid arthritis (RA; n = 73) were included from the COPANARD (Corona Pandemic Autoimmune Rheumatic Disease) cohort, followed since the beginning of the COVID‐19 pandemic. Patients received the BNT162b2 vaccine between December 2020 and April 2021. All patients had total antibodies against SARS‐CoV‐2 measured before vaccination and 1 week after the second vaccination (VITROS Immunodiagnostic Products).ResultsOf 134 patients (median age, 70 years), 77% were able to mount a detectable serological response to the vaccine. Among patients treated with rituximab, only 24% had detectable anti–SARS‐CoV‐2 antibodies in their serum after vaccination. The time since the last rituximab treatment did not seem to influence the vaccine response. No significant difference was observed between patients with RA or SLE when adjusting for treatment, and no correlation between antibody levels and age was detected (r = −0.12; P = 0.18).ConclusionAntibody measurements against SARS‐CoV‐2 in patients with RA and SLE after two doses of the BNT162b2 vaccine demonstrated that 23% of patients could not mount a detectable serological response to the vaccine. B cell–depleting therapy (BCDT) is of specific concern, and our findings call for particular attention to the patients receiving BCDT.

Effectiveness of an Inactivated SARS-CoV-2 Vaccine in Chile

BackgroundMass vaccination campaigns to prevent coronavirus disease 2019 (Covid-19) are occurring in many countries; estimates of vaccine effectiveness are urgently needed to support decision making. A countrywide mass vaccination campaign with the use of an inactivated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine (CoronaVac) was conducted in Chile starting on February 2, 2021.MethodsWe used a prospective national cohort, including participants 16 years of age or older who were affiliated with the public national health care system, to assess the effectiveness of the inactivated SARS-CoV-2 vaccine with regard to preventing Covid-19 and related hospitalization, admission to the intensive care unit (ICU), and death. We estimated hazard ratios using the extension of the Cox proportional-hazards model, accounting for time-varying vaccination status. We estimated the change in the hazard ratio associated with partial immunization (≥14 days after receipt of the first dose and before receipt of the second dose) and full immunization (≥14 days after receipt of the second dose). Vaccine effectiveness was estimated with adjustment for individual demographic and clinical characteristics.ResultsThe study was conducted from February 2 through May 1, 2021, and the cohort included approximately 10.2 million persons. Among persons who were fully immunized, the adjusted vaccine effectiveness was 65.9% (95% confidence interval [CI], 65.2 to 66.6) for the prevention of Covid-19 and 87.5% (95% CI, 86.7 to 88.2) for the prevention of hospitalization, 90.3% (95% CI, 89.1 to 91.4) for the prevention of ICU admission, and 86.3% (95% CI, 84.5 to 87.9) for the prevention of Covid-19–related death.ConclusionsOur results suggest that the inactivated SARS-CoV-2 vaccine effectively prevented Covid-19, including severe disease and death, a finding that is consistent with results of phase 2 trials of the vaccine. (Funded by Agencia Nacional de Investigación y Desarrollo and others.)

Knowledge and Practice Regarding Coronavirus Disease Prevention (COVID-19) Among Internally Displaced Persons in Camps in Central Darfur Region, Sudan

Background: The lacking healthcare system services in conflict areas and the emergence of infection with a pandemic of coronavirus disease may exacerbate the humanitarian crisis among the camp residents in the central Dafur region of Sudan. Adequate knowledge and practices are vital to prevent coronavirus disease 2019 (COVID-19). Therefore, this study aimed to investigate the knowledge and practice regarding COVID-19 among internally displaced persons in Sudan.
 Methods: In this cross-sectional study, data were collected through an online survey using a self-administered questionnaire. Convenience sampling method was used for the internally displaced persons in two camps of Zalingei town, central Darfur region, Sudan.
 Results: In total, 143 participants responded; 75 (52.4%) of them were female, while 68 (47.6%) were male; 49 (34.3%) were between the age of 50 and 60 years; 78 (54.5%) were formally uneducated; 126 (88.1%) did not have a chronic disease; and 56 (39.2%) knew about COVID-19 from their relatives and friends. The overall mean of participants’ knowledge toward COVID-19 was 3.68 (SD ± 0.60(, denoting good with a rate of 73.6% and that of the practice was 2.65 (SD ±1.08), denoting moderate with a rate of 53%. A positive correlation was seen between knowledge and practice (r = 0.700, p < 0.000). Statistically significant differences were observed between the mean score of knowledge and practice with age, education, and information sources (p < 0.0001). While graduates showed a higher knowledge (116.29, p = 0.000), secondary respondents showed a higher practice (115.04, p = 0.000) than others.
 Conclusion: This study suggests educational intervention and awareness programs for uneducated and older people.

The Relationship of a Balanced Nutrition Lifestyle in the Prevention of Corona Virus Disease 2019 (Covid-19) in Watotika Ile Village, Demon Pagong District, East Flores Regency, Nusa Tenggara Timur Province

Introduction: Coronavirus is a virus that can cause illness or health problems with either mild symptoms or severe symptoms even to death, this virus can pass from one person to another through small droplets or splashes. when someone coughs or sneezes, these droplets can be directly exposed to people around or through objects touched by others which then touch the nose, eyes, mouth and finally until the person is infected with the virus. This study aims to determine the relationship between a balanced nutritional lifestyle in the prevention of Corona Virus Disease 2019 (COVID-19) in Watotika Ile Village, Demon Pagong District, East Flores Regency, Nusa Tenggara Timur (NTT) Province. Methods: This research was conducted using analytic survey, quantitative method with cross sectional study approach. The sample of this study was taken by purposive sampling with a total sample of 107 respondents. The research instrument used a questionnaire, the Food Frequency Questionnaire (FFQ) form and the International Physical Activity Questionnaire (IPAQ) guide. Analysis of quantitative data using the chi-square test. Result: The results of the study from 107 respondents based on the chi-square test of significance, there was a relationship between the habit of consuming various foods with the prevention of Corona Virus Disease 2019 (COVID-19) with a Value of 0.008 (ρ<0.05), there was a relationship between a clean lifestyle and prevention efforts. Corona Virus Disease 2019 (COVID-19) with value 0.030 (ρ<0.05), there is a relationship between physical activity and efforts to prevent Corona Virus Disease 2019 (COVID-19) with value 0.020 (ρ<0.05). Conclusion: There is a relationship between the habit of consuming a variety of foods, a clean lifestyle and physical activity with efforts to prevent COVID-19. There is a relationship between a clean lifestyle and efforts to prevent COVID-19. Keywords: Habits of eating diverse foods, clean lifestyle, physical activity, Corona Virus Disease (COVID 19).

Nutraceutical Approach to Preventing Coronavirus Disease 2019 and Related Complications.

IntroductionSeveral months ago, Chinese authorities identified an atypical pneumonia in Wuhan city, province of Hubei (China) caused by a novel coronavirus (2019-nCoV or SARS-CoV-2). The WHO announced this new disease was to be known as “COVID-19”.Evidence AcquisitionSeveral approaches are currently underway for the treatment of this disease, but a specific cure remains to be established.Evidence SynthesisThis review will describe how the use of selected nutraceuticals could be helpful, in addition to pharmacological therapy, in preventing some COVID-19-related complications in infected patients.ConclusionsEven if a specific and effective cure for COVID-19 still has some way to go, selected nutraceuticals could be helpful, in addition to pharmacological therapy, in preventing some COVID-19-related complications in infected patients.

SARS-CoV-2 Variants and Vaccines

SummaryViral variants of concern may emerge with dangerous resistance to the immunity generated by the current vaccines to prevent coronavirus disease 2019 (Covid-19). Moreover, if some variants of concern have increased transmissibility or virulence, the importance of efficient public health measures and vaccination programs will increase. The global response must be both timely and science based.

Clinical study evaluating the efficacy of ivermectin in COVID-19 treatment: A randomized controlled study.

Researchers around the world are working at record speed to find the best ways to treat and prevent coronavirus disease 2019 (COVID‐19). This study aimed to evaluate the efficacy of ivermectin for the treatment of hospitalized mild to moderate COVID‐19 infected patients. This was a randomized open‐label controlled study that included 164 patients with COVID‐19. Patients were randomized into two groups where Group 1 (Ivermectin group) included patients who received ivermectin 12 mg once daily for 3 days with standard care and Group 2 (control group) included patients who received standard protocol of treatment alone for 14 days. The main outcomes were mortality, the length of hospital stay, and the need for mechanical ventilation. All patients were followed up for 1 month. Overall, 82 individuals were randomized to receive ivermectin plus standard of care and 82 to receive standard of care alone. Patients in the ivermectin group had a shorter length of hospital stay (8.82 ± 4.94 days) than the control group (10.97 ± 5.28 days), but this was not statistically significant (p = 0.085). Three patients (3.7%) in each group required mechanical ventilation (p = 1.00). The death rate was three patients in the ivermectin group (3.7%) versus four patients (4.9%) in the control group without any significant difference between the two groups (p = 1.00). Although there was no statistically significant difference in any endpoints by ivermectin doses (12 mg/day for 3 days); there was an observed trend to reducing hospital stay in the ivermectin‐treated group.

Preventive Practice and Associated Factors Toward Coronavirus Disease 19 in Adigrat Town, Northern Ethiopia: Community-Based Cross-Sectional Study.

PurposeThe global coronavirus disease 19 pandemic is an unprecedented crisis, unlike any since the end of the Second World War. Yet no successful vaccine or treatment has been reported. Even though increasing the practice of the community is critical to prevent coronavirus disease 19 pandemic, there is limited study in Ethiopia particularly in the study area. Therefore, the study aimed to assess practice and associated factors toward coronavirus disease 19.ObjectiveTo assess the prevalence and associated factors with practice toward coronavirus disease 19 prevention in Adigrat residents, Northern Ethiopia, 2020.MethodsA community-based cross-sectional study design was carried out among 421 Adigrat Town residents from September 10 to 20, 2020. Households were selected using systematic sampling technique. To identify determinant factors, binary logistic regression analyses were employed with confidence interval of 95%. To identify statistically significant factors, the adjusted odds ratio (AOR) was used. Statisticalsignificance was determined at P-value <0.05.ResultsThe prevalence of poor practice was 32.2% (95% CI (31.5–38.5%)). Age of 20–29 (AOR=2.1, 95% CI (1.9–6.5)), occupational status of unemployed (AOR=1.5, CI 95% (1.4–1.9)), marital status of unmarried (AOR=1.9, 95% CI (1.2–12.5)), and educational status of cannot read and write (AOR=2.1, 95% CI (2.0–9.3)) were statistically significant factors toward COVID-19 prevention.ConclusionThe poor practice toward coronavirus disease 19 prevention was significantly high. Age, occupation, marital status, and educational status were significantly associated with the preventive practice toward the coronavirus disease 19. It would be helpful if the health professionals or other volunteers inform the community continuously by giving health educations regarding the preventive ways to increase the practice.

Guidelines for Mountain Rescue During the COVID-19 Pandemic: Official Guidelines of the International Commission for Alpine Rescue.

Roy, Steven, Inigo Soteras, Alison Sheets, Richard Price, Kazue Oshiro, Simon Rauch, Don McPhalen, Maria Antonia Nerin, Giacomo Strapazzon, Myron Allen, Alistair Read, and Peter Paal. Guidelines for mountain rescue during the COVID-19 pandemic: official guidelines of the International Commission for Alpine Rescue. High Alt Med Biol. 22: 128–141, 2021.Background: In mountain rescue, uncertainty exists on the best practice to prevent coronavirus disease 2019 (COVID-19) transmission. The aim of this work was to provide a state-of-the-art overview of the challenges caused by the COVID-19 pandemic in mountain rescue.Methods: Original articles or reviews, published until December 27, 2020 in Cochrane COVID-19 Study Register, EMBASE, PubMed, and Google Scholar were included. Articles were limited to English, French, German, or Spanish with the article topic COVID-19 or other epidemics, addressing transmission, transport, rescue, or cardiopulmonary resuscitation.Results: The literature search yielded 6,190 articles. A total of 952 were duplicates and 5,238 were unique results. After exclusion of duplicates and studies that were not relevant to this work, 249 articles were considered for this work. Finally, 72 articles and other sources were included.Conclusions: Recommendations are provided for protection of the rescuer (including screening, personal protective equipment [PPE], and vaccination), protection of the patient (including general masking if low risk, specific PPE if high risk), equipment hygiene (including disinfection after every mission), use of single-use products, training and medical measures under COVID-19 precautions, and psychological wellbeing of rescuers during the COVID-19 pandemic. Adapted COVID-19 precautions for low-and-medium-income countries are also discussed.

Lack of effects on female fertility and prenatal and postnatal offspring development in rats with BNT162b2, a mRNA-based COVID-19 vaccine

BNT162b2 is a vaccine developed to prevent coronavirus disease 2019 (COVID-19). BNT162b2 is a lipid nanoparticle formulated nucleoside-modified messenger RNA (mRNA) encoding the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein locked in its prefusion conformation. A developmental and reproductive toxicity study was conducted in rats according to international regulatory guidelines. The full human BNT162b2 dose of 30 μg mRNA/dose (>300 times the human dose on a mg/kg basis) was administered intramuscularly to 44 female rats 21 and 14 days prior to mating and on gestation days 9 and 20. Half of the rats were subject to cesarean section and full fetal examination at the end of gestation, and the other half were allowed to deliver and were monitored to the end of lactation. A robust neutralizing antibody response was confirmed prior to mating and at the end of gestation and lactation. The presence of neutralizing antibodies was also confirmed in fetuses and offspring. Nonadverse effects, related to the local injection site reaction, were noted in dams as expected from other animal studies and consistent with observations in humans. There were no effects of BNT162b2 on female mating performance, fertility, or any ovarian or uterine parameters nor on embryo-fetal or postnatal survival, growth, physical development or neurofunctional development in the offspring through the end of lactation. Together with the safety profile in nonpregnant people, this ICH-compliant nonclinical safety data supports study of BNT162b2 in women of childbearing potential and pregnant and lactating women.

In vitro activity of itraconazole against SARS-CoV-2.

Although vaccination campaigns are currently being rolled out to prevent coronavirus disease (COVID‐19), antivirals will remain an important adjunct to vaccination. Antivirals against coronaviruses do not exist, hence global drug repurposing efforts have been carried out to identify agents that may provide clinical benefit to patients with COVID‐19. Itraconazole, an antifungal agent, has been reported to have activity against animal coronaviruses. Using cell‐based phenotypic assays, the in vitro antiviral activity of itraconazole and 17‐OH itraconazole was assessed against clinical isolates from a German and Belgian patient infected with severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2). Itraconazole demonstrated antiviral activity in human Caco‐2 cells (EC50 = 2.3 µM; 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay). Similarly, its primary metabolite, 17‐OH itraconazole, showed inhibition of SARS‐CoV‐2 activity (EC50 = 3.6 µM). Remdesivir inhibited viral replication with an EC50 = 0.4 µM. Itraconazole and 17‐OH itraconazole resulted in a viral yield reduction in vitro of approximately 2‐log10 and approximately 1‐log10, as measured in both Caco‐2 cells and VeroE6‐eGFP cells, respectively. The viral yield reduction brought about by remdesivir or GS‐441524 (parent nucleoside of the antiviral prodrug remdesivir; positive control) was more pronounced, with an approximately 3‐log10 drop and >4‐log10 drop in Caco‐2 cells and VeroE6‐eGFP cells, respectively. Itraconazole and 17‐OH itraconazole exert in vitro low micromolar activity against SARS‐CoV‐2. Despite the in vitro antiviral activity, itraconazole did not result in a beneficial effect in hospitalized COVID‐19 patients in a clinical study (EudraCT Number: 2020‐001243‐15).

Knowledge and practice to prevent COVID-19 and its associated factors among pregnant women in Debre Tabor Town Northwest Ethiopia, a community-based cross-sectional study

BackgroundCoronavirus disease is now a global concern with the non-availability of antiviral treatment and attacks all groups of the population. Hence, applying preventive measures is the most critical intervention to control the infection. Pregnant women are particularly susceptible to respiratory pathogens because of their immunosuppressive state and physiological adaptive change during pregnancy. Therefore, this study was aimed to assess knowledge and practice to prevent coronavirus disease and its associated factors among pregnant women in Debre Tabor Town.MethodsCommunity-based cross-sectional study was conducted among 422 participants from May 25–June 15, 2020. A simple random sampling technique was employed. Data were collected by face-to-face interview using a structured and pre-tested questionnaire and analysis using SPSS version 23. Bivariable and multivariable logistic regression analysis was carried out and p-value < 0.05 at 95% CI were considered as statistically significant.ResultsOverall 46.8 and 47.6% of women were knowledgeable and had good practice to prevent coronavirus respectively. Women’s age (15–24 years) (AOR = 4.85, 95% CI: 1.34–5.42), educational status (AOR:3.70; 95% CI: 1.16–5.40) being civil servant (AOR:2.84; 95% CI: 1.55–5.21), wanted pregnancy (AOR:3.37; 95% CI: 1.20–9.45), antenatal care follow-up (AOR:2.07; 95% CI: 1.03–4.13) were significantly associated with COVID-19 knowledge, whereas educational status (AOR:3.78; 95% CI: 1.19–5.11), number of children (AOR:2.89; 95% CI: 1.29–6.45) and knowledge (AOR:8.42;95% CI: 4.50–15.85), were also found to be statistically significant with practice.ConclusionsMost of the participants had poor knowledge and inappropriate practice. Increasing health education programs via different media, coordinated and combined efforts of authorities and all individuals will be needed to battles the spread of the infection.

Natural ventilation strategy and related issues to prevent coronavirus disease 2019 (COVID-19) airborne transmission in a school building

The World Health Organization (WHO) announced that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may spread through aerosols, so-called airborne transmission, especially in a poorly ventilated indoor environment. Ventilation protects the occupants against airborne transmission. Various studies have been performed on the importance of sufficient ventilation for diluting the concentration of virus and lowering any subsequent dose inhaled by the occupants. However, the ventilation situation can be problematic in public buildings and other shared spaces, such as shops, offices, schools, and restaurants. If ventilation is provided by opening windows, the outdoor airflow rate depends strongly on the specific local conditions (opening sizes, relative positions, climatic and weather conditions).This study uses field measurements to analyze the natural ventilation performance in a school building according to the window opening rates, positions, and weather conditions. The ventilation rates were calculated by the tracer gas decay method, and the infection risk was assessed using the Wells-Riley equation. Under cross-ventilation conditions, the average ventilation rates were measured at 6.51 h−1 for 15% window opening, and 11.20 h−1 for 30% window opening. For single-sided ventilation, the ventilation rates were reduced to about 30% of the values from the cross-ventilation cases. The infection probability is less than 1% in all cases when a mask is worn and more than 15% of the windows are open with cross-ventilation. With single-sided ventilation, if the exposure time is less than 1 h, the infection probability can be kept less than 1% with a mask. However, the infection probability exceeds 1% in all cases where exposure time is greater than 2 h, regardless of whether or not a mask is worn. Also, when the air conditioner was operated with a window opening ratio of 15%, power consumption increased by 10.2%.

Recent SPN Position Statements

Recent SPN Position Statements

“COVID Arm”: Very delayed large injection site reactions to mRNA COVID-19 vaccines

“COVID Arm”: Very delayed large injection site reactions to mRNA COVID-19 vaccines

Cloth Masks May Prevent Transmission of COVID-19

LettersApril 2021Cloth Masks May Prevent Transmission of COVID-19FREEKouji H. Harada, PhD, MPH, Mariko Harada Sassa, MD, PhDKouji H. Harada, PhD, MPHKyoto University Graduate School of Medicine, Kyoto, JapanSearch for more papers by this author, Mariko Harada Sassa, MD, PhDKyoto University Graduate School of Medicine, Kyoto, JapanSearch for more papers by this authorAuthor, Article, and Disclosure Informationhttps://doi.org/10.7326/L21-0088 SectionsAboutVisual AbstractPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinkedInRedditEmail TO THE EDITOR: We appreciate Clase and colleagues' (1) efforts to show the potential efficacy of cloth masks in filtering virus-containing aerosols. The effect of wearing masks in the community to prevent coronavirus disease 2019 (COVID-19) is worth investigating. However, we have several concerns.Clase and colleagues cite an unpublished review (2) on the effects of face masks and state that integrated odds ratios were between 0.81 and 0.95. Three of the 4 cited odds ratios were derived in home environments where a member of the household was infected with influenza-like illness. Only 1 odds ratio integrated from 3 studies done in a university residence and during the hajj pilgrimage was 0.94 (95% CI, 0.75 to 1.19).Even if wearing masks reduces the risk for transmission by 6%, extrapolating how this measure will benefit the general community is difficult. Public health interventions requiring that populations wear masks may reduce transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) without harm. If authorities can spend sufficient funds, advocacy and distribution of materials are feasible. However, implementation of physical distancing, hand hygiene, and sanitation is not perfect. How should authorities allocate resources? The cost-effectiveness of cloth masks should be evaluated in comparison to that of other options.