Intranasal mRNA-LNP vaccination protects hamsters from SARS-CoV-2 infection (preprint)

Intranasal vaccination represents a promising approach for preventing disease caused by respiratory pathogens by eliciting a mucosal immune response in the respiratory tract that may act as an early barrier to infection and transmission. This study investigated immunogenicity and protective efficacy of intranasally administered messenger RNA (mRNA)-lipid nanoparticle (LNP) encapsulated vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Syrian golden hamsters. Intranasal mRNA-LNP vaccination systemically induced spike-specific binding (IgG and IgA) and neutralizing antibodies with similar robustness to intramuscular controls. Additionally, intranasal vaccination decreased viral loads in the respiratory tract, reduced lung pathology, and prevented weight loss after SARS-CoV-2 challenge. This is the first study to demonstrate successful immunogenicity and protection against respiratory viral infection by an intranasally administered mRNA-LNP vaccine.

Corrigendum: Covid-19 Lockdown in Spring 2020 in France Provided Unexpected Opportunity to Assess Health Impacts of Falls in Air Pollution(Front. Sustain. Cities, (2022), 3, (643821), 10.3389/frsc.2021.643821)

In the original article, there was a wording error on the way that the reduction percentages of air pollutant concentrations were expressed. It is not a reduction percentage but a percentage of increase that would have been observed in the absence of lockdown. A correction has been made to Discussion, “Summary of Findings,” first paragraph: We replaced the following sentences: “The mean reduction in PM10 concentrations was 8.3%, with values ranging from−1.8 to 39.8% depending on the municipality. For NO2 concentrations, the mean reduction was 29.0%, with values ranging from 3.5 to 187.8% depending on the municipality.” by: “The daily mean difference between the estimated PM10 level during lockdown and its reference (modeled concentrations without lockdown) was −8.3 μg.m−3. This difference was −2.1 μg.m−3 for NO2.”.In the original article, there was a mistake in Table 2 as published. The four columns entitled “Reduction percentage” were not defined. The corrected Table 2 appears below. The authors apologize for these errors and state that this doesnot change the scientific conclusions of the article in any way. The original article has been updated. Copyright © 2022 Adélaïde, Medina, Wagner, de Crouy-Chanel, Real, Colette, Couvidat, Bessagnet, Alter, Durou, Host, Hulin, Corso and Pascal.

Impact of air pollution on mortality in metropolitan France: reduction related to the spring 2020 lockdown and long-term impact for 2016-2019

Background - The reduction of socioeconomic activities related to the spring 2020 lockdown implemented to limit the spread of COVID-19 in France led to decreases in air pollutant concentrations. Methods - The quantitative health impact assessment method was used to estimate the impact on mortality of the French population: 1/in the short- and longer term, impacts of the decreases in particulate matter (PM10 and PM2,5) and nitrogen dioxide (NO2) levels observed during the lockdown;and 2/in the long term, impact on the total burden for the years 2016-2019. Results - The limiting of socioeconomic activities in the spring of 2020 reduced NO2 and PM population's exposures that resulted in 2,300 deaths avoided in relation to PM and nearly 1,200 in relation to NO2. The long-term impact of air pollution on mortality is estimated at nearly 40,000 annual deaths attributable to PM2.5 exposure and nearly 7,000 deaths attributable to NO2 exposure. Conclusion - These results show that short-term reductions in air pollution levels are associated with rapid, measurable health benefits. They confirm that even short-term public actions that reduce air pollution levels (different from lockdown, which is obviously not desirable) appear to have a significant impact on health. Moreover, the results underline that on the long-term, although mortality related to ambient air pollution shows a slight downward trend, it remains a significant risk factor in France. Therefore, efforts to reduce air pollution and associated mortality must be pursued lastingly for all sources of air pollution through tailored, ambitious policies.

The effects of lockdown on air quality: a look back at spring 2020

This article presents an analysis of the impact on air quality of lockdown measures implemented throughout Europe for nearly two months in spring 2020 to combat the Covid-19 health crisis. These measures have resulted in a drastic and unprecedented reduction in nitrogen dioxide emissions, mainly emitted by road traffic. Several European teams have conducted studies with the same objective, but with possibly different methods. Here, we applied two approaches based on the implementation of the CHIMERE chemistry-transport model to France and to Europe. One is based on the use of air quality simulations in which measurement data from in-situ monitoring networks are adjusted to correspond closely to observations. The other interprets emission reduction scenarios typical of lockdown measures. The advantages and disadvantages of each are discussed. However, they lead to conclusions that are consistent with each other, and with most of the studies identified on the subject: lockdown naturally decreased nitrogen dioxide concentrations by up to 60% in all large European cities. These studies make it possible to set an upper limit of these levels which will be difficult to lower. On the other hand, the levels of particulate matter, which is influenced by sources other than road traffic and by complex physicochemical phenomena, decreased less and followed a different curve, as the lockdown effect was felt a few days later. These results provide essential insights for decision-makers designing public policies for air quality.

Antibody Responses to SARS-CoV-2 Following an Outbreak Among Marine Recruits With Asymptomatic or Mild Infection.

We investigated serological responses following a SARS-CoV-2 outbreak in spring 2020 on a US Marine recruit training base. 147 participants that were isolated during an outbreak of respiratory illness were enrolled in this study, with visits approximately 6 and 10 weeks post-outbreak (PO). This cohort is comprised of young healthy adults, ages 18-26, with a high rate of asymptomatic infection or mild symptoms, and therefore differs from previously reported longitudinal studies on humoral responses to SARS-CoV-2, which often focus on more diverse age populations and worse clinical presentation. 80.9% (119/147) of the participants presented with circulating IgG antibodies against SARS-CoV-2 spike (S) receptor-binding domain (RBD) at 6 weeks PO, of whom 97.3% (111/114) remained positive, with significantly decreased levels, at 10 weeks PO. Neutralizing activity was detected in all sera from SARS-CoV-2 IgG positive participants tested (n=38) at 6 and 10 weeks PO, without significant loss between time points. IgG and IgA antibodies against SARS-CoV-2 RBD, S1, S2, and the nucleocapsid (N) protein, as well neutralization activity, were generally comparable between those participants that had asymptomatic infection or mild disease. A multiplex assay including S proteins from SARS-CoV-2 and related zoonotic and human endemic betacoronaviruses revealed a positive correlation for polyclonal cross-reactivity to S after SARS-CoV-2 infection. Overall, young adults that experienced asymptomatic or mild SARS-CoV-2 infection developed comparable humoral responses, with no decrease in neutralizing activity at least up to 10 weeks after infection.

The COVID-19 pandemic has changed dying and grief: Will there be a surge of complicated grief?

Worldwide, more than 3 million people have died from COVID-19. Each decedent represents a person who was loved, will be missed, and whose death elicited grief. COVID-19 has changed the way we die and grieve. Many people have died without family members and friends present and many of the bereft have grieved and mourned alone. Individuals and communities have experienced multiple losses within a short time while suffering from concomitant stress, anxiety, and depression. More deaths and more grief will continue in the foreseeable future. Preventive education is needed to prepare for and manage the likely increase in complicated grief.

Topoisomerase III-ß is required for efficient replication of positive-sense RNA viruses.

Based on genome-scale loss-of-function screens we discovered that Topoisomerase III-ß (TOP3B), a human topoisomerase that acts on DNA and RNA, is required for yellow fever virus and dengue virus-2 replication. Remarkably, we found that TOP3B is required for efficient replication of all positive-sense-single stranded RNA viruses tested, including SARS-CoV-2. While there are no drugs that specifically inhibit this topoisomerase, we posit that TOP3B is an attractive anti-viral target.

COVID-19 brings a new urgency for advance care planning: Implications of death education.

The U.S. has the highest number of coronavirus disease (COVID-19) cases and deaths of any nation. Deaths due to COVID-19, especially among older adults and people of color, have created an urgency for advanced care planning (ACP). Despite benefits of ACP, only one-third of U.S. adults have completed advance directives, in part due to a lack of death education. We recommend four actions to increase death education and ACP completion: (1) integrate death education into teacher preparation programs, (2) incorporate death education in undergraduate curricula, (3) provide better education in death and dying to future health professionals, and (4) educate the public.