We identified seasonal human coronaviruses, influenza viruses and rhinoviruses in exhaled breath and coughs of children and adults with acute respiratory illness. Surgical face masks significantly ...reduced detection of influenza virus RNA in respiratory droplets and coronavirus RNA in aerosols, with a trend toward reduced detection of coronavirus RNA in respiratory droplets. Our results indicate that surgical face masks could prevent transmission of human coronaviruses and influenza viruses from symptomatic individuals.
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FZAB, GEOZS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Influenza virus infections are believed to spread mostly by close contact in the community. Social distancing measures are essential components of the public health response to influenza pandemics. ...The objective of these mitigation measures is to reduce transmission, thereby delaying the epidemic peak, reducing the size of the epidemic peak, and spreading cases over a longer time to relieve pressure on the healthcare system. We conducted systematic reviews of the evidence base for effectiveness of multiple mitigation measures: isolating ill persons, contact tracing, quarantining exposed persons, school closures, workplace measures/closures, and avoiding crowding. Evidence supporting the effectiveness of these measures was obtained largely from observational studies and simulation studies. Voluntary isolation at home might be a more feasible social distancing measure, and pandemic plans should consider how to facilitate this measure. More drastic social distancing measures might be reserved for severe pandemics.
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DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
There were 3 influenza pandemics in the 20th century, and there has been 1 so far in the 21st century. Local, national, and international health authorities regularly update their plans for ...mitigating the next influenza pandemic in light of the latest available evidence on the effectiveness of various control measures in reducing transmission. Here, we review the evidence base on the effectiveness of nonpharmaceutical personal protective measures and environmental hygiene measures in nonhealthcare settings and discuss their potential inclusion in pandemic plans. Although mechanistic studies support the potential effect of hand hygiene or face masks, evidence from 14 randomized controlled trials of these measures did not support a substantial effect on transmission of laboratory-confirmed influenza. We similarly found limited evidence on the effectiveness of improved hygiene and environmental cleaning. We identified several major knowledge gaps requiring further research, most fundamentally an improved characterization of the modes of person-to-person transmission.
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DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
International travel-related nonpharmaceutical interventions (NPIs), which can include traveler screening, travel restrictions, and border closures, often are included in national influenza pandemic ...preparedness plans. We performed systematic reviews to identify evidence for their effectiveness. We found 15 studies in total. Some studies reported that NPIs could delay the introduction of influenza virus. However, no available evidence indicated that screening of inbound travelers would have a substantial effect on preventing spread of pandemic influenza, and no studies examining exit screening were found. Some studies reported that travel restrictions could delay the start of local transmission and slow international spread, and 1 study indicated that small Pacific islands were able to prevent importation of pandemic influenza during 1918-19 through complete border closure. This limited evidence base indicates that international travel-related NPIs would have limited effectiveness in controlling pandemic influenza and that these measures require considerable resources to implement.
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DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Health agencies recommend transmission-based precautions, including contact, droplet and airborne precautions, to mitigate transmission of respiratory viruses in healthcare settings. There is ...particular controversy over the importance of aerosol transmission and whether airborne precautions should be recommended for some respiratory viruses. Here, we review the current recommendations of transmission-based precautions and the latest evidence on the aerosol transmission of respiratory viruses.
Viral nucleic acids, and in some instances viable viruses, have been detected in aerosols in the air in healthcare settings for some respiratory viruses such as seasonal and avian influenza viruses, Middle East respiratory syndrome-coronavirus and respiratory syncytial virus. However, current evidences are yet to demonstrate that these viruses can effectively spread via airborne route between individuals, or whether preventive measures in airborne precautions would be effective.
Studies that use transmission events as outcome to demonstrate human-to-human transmission over the aerosol route or quantitative measurement of infectious respiratory viruses in the air are needed to evaluate the infectiousness of respiratory viruses over the aerosol route. When a respiratory virus in concern only leads to disease with low severity, airborne precautions are not likely to be justified.
PURPOSE OF REVIEWHealth agencies recommend transmission-based precautions, including contact, droplet and airborne precautions, to mitigate transmission of respiratory viruses in healthcare settings. ...There is particular controversy over the importance of aerosol transmission and whether airborne precautions should be recommended for some respiratory viruses. Here, we review the current recommendations of transmission-based precautions and the latest evidence on the aerosol transmission of respiratory viruses.
RECENT FINDINGSViral nucleic acids, and in some instances viable viruses, have been detected in aerosols in the air in healthcare settings for some respiratory viruses such as seasonal and avian influenza viruses, Middle East respiratory syndrome-coronavirus and respiratory syncytial virus. However, current evidences are yet to demonstrate that these viruses can effectively spread via airborne route between individuals, or whether preventive measures in airborne precautions would be effective.
SUMMARYStudies that use transmission events as outcome to demonstrate human-to-human transmission over the aerosol route or quantitative measurement of infectious respiratory viruses in the air are needed to evaluate the infectiousness of respiratory viruses over the aerosol route. When a respiratory virus in concern only leads to disease with low severity, airborne precautions are not likely to be justified.
We studied 2780 adults in Hong Kong who received CoronaVac inactivated virus vaccine (Sinovac) and BNT162b2 mRNA vaccine (“Comirnaty”, BioNTech/Fosun Pharma). We compared rates of antibody waning ...over time using an enzyme-linked immunosorbent assay for spike receptor binding domain and a surrogate virus neutralization test. We found stronger and more durable antibody responses to two doses of the mRNA vaccine, and slightly stronger initial antibody responses to each vaccine in younger adults and women. The weaker and less durable responses following CoronaVac support earlier provision of third doses to persons who previously received two doses of this vaccine.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Background. School-aged children suffer high rates of influenza virus infections and associated illnesses each year, and are a major source of transmission in the community. However, information on ...the cumulative incidence of infection in specific epidemics is scarce, and there are limited studies with sufficient follow-up to identify the strength and duration of protection against reinfection. Methods. We randomly allocated children 5–17 years of age to receive trivalent inactivated influenza vaccine (TIV) or placebo from September 2009 through January 2010, and then conducted follow-up for 3 years including regular collection of sera, symptom diaries, and collection of nose and throat swabs during illness episodes in participants or their household members. Results. Of 796 children initially randomized, 484 continued to participate for all 3 years. In unvaccinated children, cumulative incidence of infection was estimated to be 59% in the first wave of H1N1pdm09 in 2009–2010, and 7%, 14%, 20%, and 31% in subsequent epidemics of H3N2 (2010), H1N1pdm09 (2011), B (2012), and H3N2 (2012), respectively. Infection with H1N1pdm09 in 2009–2010 and H3N2 in 2010 was associated with protection against infection with subsequent epidemics of the same subtype in 2011 and 2012, respectively, but we found no evidence of heterotypic or heterosubtypic protection against infection. Conclusions. We identified substantial incidence of influenza virus infections in children in Hong Kong in 5 major epidemics over a 3-year period, and evidence of homosubtypic but not heterosubtypic protection following infection. Clinical Trials Registration. NCT00792051.
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BFBNIB, NUK, PNG, UL, UM, UPUK