Advanced search in Research products
Research products
arrow_drop_down
Searching FieldsTerms
Any field
arrow_drop_down
includes
arrow_drop_down
Include:
The following results are related to COVID-19. Are you interested to view more results? Visit OpenAIRE - Explore.
138 Research products, page 1 of 14

  • COVID-19
  • Publications
  • Other research products
  • 2013-2022
  • French National Research Agency (ANR)
  • English
  • Hal-Diderot
  • HAL-IRD
  • COVID-19

10
arrow_drop_down
Date (most recent)
arrow_drop_down
  • Open Access English
    Authors: 
    Anna Zaytseva; Pierre Verger; Bruno Ventelou;
    Publisher: HAL CCSD
    Country: France
    Project: ANR | AMSE (EUR) (ANR-17-EURE-0020)

    Abstract Background Given the importance of the continuous follow-up of chronic patients, we evaluated the performance of French private practice general practitioners (GPs) practicing in multi-professional group practices (MGP) regarding chronic care management during the first Covid-19 lockdown in Spring 2020 compared to GPs not in MGP. We consider two outcomes: continuity of care provision for chronic patients and proactivity in contacting these patients. Methods The cross-sectional web questionnaire of 1191 GPs took place in April 2020. We exploit self-reported data on: 1) the frequency of consultations for chronic patients during lockdown compared to their “typical” week before the pandemic, along with 2) GPs’ proactive behaviour when contacting their chronic patients. We use probit and bivariate probit models (adjusted for endogeneity of choice of engagement in MGP) to test whether GPs in MGP had significantly different responses to the Covid-19 crisis compared to those practicing outside MGP. Results Out of 1191 participants (response rate: 43.1%), around 40% of GPs were female and 34% were younger than 50 years old. Regression results indicate that GPs in MGP were less likely to experience a drop in consultations related to complications of chronic diseases (− 45.3%). They were also more proactive (+ 13.4%) in contacting their chronic patients compared to their peers practicing outside MGP. Conclusion We demonstrate that the MGP organisational formula was beneficial to the follow-up of patients with chronic conditions during the lockdown; therefore, it appears beneficial to expand integrated practices, since they perform better when facing a major shock. Further research is needed to confirm the efficiency of these integrated practices outside the particular pandemic setup.

  • Open Access English
    Authors: 
    Vimbiso Chidoti; Hélène De Nys; Valérie Pinarello; Getrude Mashura; Dorothée Missé; Laure Guerrini; Davies Pfukenyi; Julien Cappelle; Ngoni Chiweshe; Ahidjo Ayouba; +5 more
    Publisher: Preprints
    Country: France
    Project: ANR | MUSE (ANR-16-IDEX-0006)

    International audience; Background: Studies have linked bats to outbreaks of viral diseases in human populations such as SARS-CoV-1 and MERS-CoV and the ongoing SARS-CoV-2 pandemic. Methods: We carried out a longitudinal survey from August 2020 to July 2021 at two sites in Zimbabwe with bat–human interactions: Magweto cave and Chirundu farm. A total of 1732 and 1866 individual bat fecal samples were collected, respectively. Coronaviruses and bat species were amplified using PCR systems. Results: Analysis of the coronavirus sequences revealed a high genetic diversity, and we identified different sub-viral groups in the Alphacoronavirus and Betacoronavirus genus. The established sub-viral groups fell within the described Alphacoronavirus sub-genera: Decacovirus, Duvinacovirus, Rhinacovirus, Setracovirus and Minunacovirus and for Betacoronavirus sub-genera: Sarbecoviruses, Merbecovirus and Hibecovirus. Our results showed an overall proportion for CoV positive PCR tests of 23.7% at Chirundu site and 16.5% and 38.9% at Magweto site for insectivorous bats and Macronycteris gigas, respectively. Conclusions: The higher risk of bat coronavirus exposure for humans was found in December to March in relation to higher viral shedding peaks of coronaviruses in the parturition, lactation and weaning months of the bat populations at both sites. We also highlight the need to further document viral infectious risk in human/domestic animal populations surrounding bat habitats in Zimbabwe.

  • Open Access English
    Authors: 
    Emma Hubert; Thibaut Mastrolia; Dylan Possamaï; Xavier Warin;
    Publisher: HAL CCSD
    Countries: United States, France
    Project: ANR | PACMAN (ANR-16-CE05-0027)

    In this work, we provide a general mathematical formalism to study the optimal control of an epidemic, such as the COVID-19 pandemic, via incentives to lockdown and testing. In particular, we model the interplay between the government and the population as a principal-agent problem with moral hazard, à la Cvitanić et al. (Finance Stoch 22(1):1-37, 2018), while an epidemic is spreading according to dynamics given by compartmental stochastic SIS or SIR models, as proposed respectively by Gray et al. (SIAM J Appl Math 71(3):876-902, 2011) and Tornatore et al. (Phys A Stat Mech Appl 354(15):111-126, 2005). More precisely, to limit the spread of a virus, the population can decrease the transmission rate of the disease by reducing interactions between individuals. However, this effort-which cannot be perfectly monitored by the government-comes at social and monetary cost for the population. To mitigate this cost, and thus encourage the lockdown of the population, the government can put in place an incentive policy, in the form of a tax or subsidy. In addition, the government may also implement a testing policy in order to know more precisely the spread of the epidemic within the country, and to isolate infected individuals. In terms of technical results, we demonstrate the optimal form of the tax, indexed on the proportion of infected individuals, as well as the optimal effort of the population, namely the transmission rate chosen in response to this tax. The government's optimisation problems then boils down to solving an Hamilton-Jacobi-Bellman equation. Numerical results confirm that if a tax policy is implemented, the population is encouraged to significantly reduce its interactions. If the government also adjusts its testing policy, less effort is required on the population side, individuals can interact almost as usual, and the epidemic is largely contained by the targeted isolation of positively-tested individuals.

  • Open Access English
    Authors: 
    Tubaro, Paola; Casilli, Antonio,;
    Publisher: HAL CCSD
    Country: France
    Project: ANR | HUSH (ANR-19-CE10-0012)

    International audience; In this paper, we analyze the recessionary effects of the COVID-19 pandemic on digital platform workers. The crisis has been described as a great work-from-home experiment, with platform ecosystems positing as its most advanced form. Our analysis differentiates the direct (health) and indirect (economic) risks incurred by workers, to critically assess the portrayal of platforms as buffers against crisis-induced layoffs. We submit that platform-mediated labor may eventually increase precarity, without necessarily reducing health risks for workers. Our argument is based on a comparison of the three main categories of platform work – “on-demand labor” (gigs such as delivery and transportation), “online labor” (tasks performed remotely, such as data annotation) and “social networking labor” (content generation and moderation). We discuss the strategies that platforms deploy to transfer risk from clients onto workers, thus deepening existing power imbalances between them. These results question the problematic equivalence between work-from-home and platform labor. Instead of attaining the advantages of the former in terms of direct and indirect risk mitigation, an increasing number of platformized jobs drift toward high economic and insuppressible health risks.

  • Open Access English
    Authors: 
    Laura Di Domenico; Giulia Pullano; Chiara E. Sabbatini; Pierre-Yves Boëlle; Vittoria Colizza;
    Publisher: HAL CCSD
    Country: France
    Project: ANR | DataRedux (ANR-19-CE46-0008), ANR | SPHINx (ANR-17-CE36-0008), EC | MOOD (874850)

    As countries in Europe implement strategies to control the COVID-19 pandemic, different options are chosen regarding schools. Through a stochastic age-structured transmission model calibrated to the observed epidemic in Île-de-France in the first wave, we explored scenarios of partial, progressive, or full school reopening. Given the uncertainty on children’s role, we found that reopening schools after lockdown may increase COVID-19 cases, yet protocols exist to keep the epidemic controlled. Under a scenario with stable epidemic activity if schools were closed, reopening pre-schools and primary schools would lead to up to 76% [67, 84]% occupation of ICU beds if no other school level reopened, or if middle and high schools reopened later. Immediately reopening all school levels may overwhelm the ICU system. Priority should be given to pre- and primary schools allowing younger children to resume learning and development, whereas full attendance in middle and high schools is not recommended for stable or increasing epidemic activity. Large-scale test and trace is required to keep the epidemic under control. Ex-post assessment shows that progressive reopening of schools, limited attendance, and strong adoption of preventive measures contributed to a decreasing epidemic after lifting the first lockdown. The role of children in the spread of COVID-19 is not fully understood, and the circumstances under which schools should be opened are therefore debated. Here, the authors demonstrate protocols by which schools in France can be safely opened without overwhelming the healthcare system.

  • Open Access English
    Authors: 
    Romain Marlin; Véronique Godot; Sylvain Cardinaud; Mathilde Galhaut; Severin Coleon; Sandra Zurawski; Nathalie Dereuddre-Bosquet; Mariangela Cavarelli; Anne-Sophie Gallouet; Pauline Maisonnasse; +28 more
    Publisher: HAL CCSD
    Country: France
    Project: ANR | IDMIT (ANR-11-INBS-0008), EC | TRANSVAC2 (730964), EC | EVAg (653316)

    Achieving sufficient worldwide vaccination coverage against SARS-CoV-2 will require additional approaches to currently approved viral vector and mRNA vaccines. Subunit vaccines may have distinct advantages when immunizing vulnerable individuals, children and pregnant women. Here, we present a new generation of subunit vaccines targeting viral antigens to CD40-expressing antigen-presenting cells. We demonstrate that targeting the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein to CD40 (αCD40.RBD) induces significant levels of specific T and B cells, with long-term memory phenotypes, in a humanized mouse model. Additionally, we demonstrate that a single dose of the αCD40.RBD vaccine, injected without adjuvant, is sufficient to boost a rapid increase in neutralizing antibodies in convalescent non-human primates (NHPs) exposed six months previously to SARS-CoV-2. Vaccine-elicited antibodies cross-neutralize different SARS-CoV-2 variants, including D614G, B1.1.7 and to a lesser extent B1.351. Such vaccination significantly improves protection against a new high-dose virulent challenge versus that in non-vaccinated convalescent animals. In this study, Marlin et al. provide insights into the potential use of subunit vaccines that induce a high level of protection against SARS-CoV-2 in animal models.

  • Open Access English
    Authors: 
    Andronico, Alessio; Tran Kiem, Cécile; Paireau, Juliette; Succo, Tiphanie; Bosetti, Paolo; Lefrancq, Noémie; Nacher, Mathieu; Djossou, Félix; Sanna, Alice; Flamand, Claude; +3 more
    Publisher: HAL CCSD
    Countries: United Kingdom, France
    Project: EC | RECoVER (101003589), ANR | INCEPTION (ANR-16-CONV-0005)

    While general lockdowns have proven effective to control SARS-CoV-2 epidemics, they come with enormous costs for society. It is therefore essential to identify control strategies with lower social and economic impact. Here, we report and evaluate the control strategy implemented during a large SARS-CoV-2 epidemic in June–July 2020 in French Guiana that relied on curfews, targeted lockdowns, and other measures. We find that the combination of these interventions coincided with a reduction in the basic reproduction number of SARS-CoV-2 from 1.7 to 1.1, which was sufficient to avoid hospital saturation. We estimate that thanks to the young demographics, the risk of hospitalisation following infection was 0.3 times that of metropolitan France and that about 20% of the population was infected by July. Our model projections are consistent with a recent seroprevalence study. The study showcases how mathematical modelling can be used to support healthcare planning in a context of high uncertainty. Identifying effective combinations of control measures in different populations is important for SARS-CoV-2 control. Here, the authors show that in French Guiana, which has a relatively young population, curfews and localised lockdowns appeared to contribute to reducing transmission.

  • Open Access English
    Authors: 
    Bertrand Achou; Philippe De Donder; Franca Glenzer; Minjoon Lee; Marie-Louise Leroux;
    Publisher: TSE Working Paper
    Country: France
    Project: SSHRC , ANR | CHESS (ANR-17-EURE-0010)

    COVID-19 outbreaks at nursing homes during the recent pandemic, which received ample media coverage, may have lasting negative impacts on individuals’ perceptions regarding ursing homes. We argue that this could have sizable and persistent implications for savings and long-term care policies. We first develop a theoretical model predicting that higher nurs- ing home aversion should induce higher savings and stronger support for policies subsidizing home care. We further document, based on a survey on Canadians in their 50s and 60s, that higher nursing home aversion is widespread: 72% of respondents are less inclined to enter a nursing home because of the pandemic. Consistent with our model, we find that the latter are much more likely to have higher intended savings for older age because of the pandemic. We also find that they are more likely to strongly support home care subsidies.

  • Open Access English
    Authors: 
    Romain Lévy; Peng Zhang; Paul Bastard; Karim Dorgham; Isabelle Melki; Alice Hadchouel; George C. Hartoularos; Bénédicte Neven; Martin Castelle; Charlotte Roy; +12 more
    Publisher: HAL CCSD
    Country: France
    Project: ANR | AABIFNCOV (ANR-20-CO11-0001)

    Significance Life-threatening COVID-19 pneumonia can be caused by rare inborn errors of type I interferon (IFN) immunity, or by autoantibodies neutralizing IFN-α2 or IFN-ω. In 2018, we reported a girl with critical influenza pneumonia due to inherited IRF9 deficiency, a component of the ISGF-3 transcription factor. We report the course of COVID-19 in the same patient. She was admitted on day 1 of upper respiratory tract infection with viremia. Administration of SARS-CoV-2–specific neutralizing monoclonal antibodies on day 2 prevented the development of pneumonia. SARS-CoV-2–specific monoclonal antibodies were sufficient to overcome a lack of ISGF-3– and IRF9-dependent type I and type III IFN immunity to the virus. They should be considered in selected children at high risk of life-threatening COVID-19. We describe an unvaccinated child at risk for life-threatening COVID-19 due to an inherited deficiency of IRF9, which governs ISGF-3–dependent responses to type I and III interferons (IFN). She was admitted, with a high nasal SARS-CoV-2 load on day 1 of upper respiratory tract infection. She was viremic on day 2 and received casirivimab and imdevimab. Her clinical manifestations and viremia disappeared on days 3 and 4, respectively. Circulating SARS-CoV-2 virus induced the expression of IFN-stimulated genes in leukocytes on day 1, whereas the secretion of blood type I IFNs, which peaked on day 4, did not. Antibody-mediated SARS-CoV-2 neutralization is, therefore, sufficient to overcome a deficiency of antiviral IFNs.

  • Open Access English
    Authors: 
    Fortuna Casoria; Fabio Galeotti; Marie Claire Villeval;
    Publisher: HAL CCSD
    Country: France
    Project: ANR | DISTANCING (ANR-20-COVI-0054), ANR | CORTEX (ANR-11-LABX-0042), ANR | IDEXLYON (ANR-16-IDEX-0005)

    In response to the pandemic of COVID-19 and in lack of pharmaceutical solutions, many countries have introduced social and physical distancing regulations to contain the transmission of the virus. These measures are effective insofar as they are able to quickly change people's habits. This is achieved by changing the monetary incentives of rule violators but also by shifting people's perception regarding the appropriateness of socialization. We studied the effect of introducing, and then lifting, distancing regulations on the perceived norm regarding social encounters. We conducted an online incentivized experiment in France where we elicited the same participants' perceived norm and social distancing behavior every week for three months. We found that people shifted behavior and norm perception as soon as the government introduced or removed distancing measures. This effect was fast acting and long lasting. This is informative for future interventions, especially in light of a possible COVID-19 recurrence.

Advanced search in Research products
Research products
arrow_drop_down
Searching FieldsTerms
Any field
arrow_drop_down
includes
arrow_drop_down
Include:
The following results are related to COVID-19. Are you interested to view more results? Visit OpenAIRE - Explore.
138 Research products, page 1 of 14
  • Open Access English
    Authors: 
    Anna Zaytseva; Pierre Verger; Bruno Ventelou;
    Publisher: HAL CCSD
    Country: France
    Project: ANR | AMSE (EUR) (ANR-17-EURE-0020)

    Abstract Background Given the importance of the continuous follow-up of chronic patients, we evaluated the performance of French private practice general practitioners (GPs) practicing in multi-professional group practices (MGP) regarding chronic care management during the first Covid-19 lockdown in Spring 2020 compared to GPs not in MGP. We consider two outcomes: continuity of care provision for chronic patients and proactivity in contacting these patients. Methods The cross-sectional web questionnaire of 1191 GPs took place in April 2020. We exploit self-reported data on: 1) the frequency of consultations for chronic patients during lockdown compared to their “typical” week before the pandemic, along with 2) GPs’ proactive behaviour when contacting their chronic patients. We use probit and bivariate probit models (adjusted for endogeneity of choice of engagement in MGP) to test whether GPs in MGP had significantly different responses to the Covid-19 crisis compared to those practicing outside MGP. Results Out of 1191 participants (response rate: 43.1%), around 40% of GPs were female and 34% were younger than 50 years old. Regression results indicate that GPs in MGP were less likely to experience a drop in consultations related to complications of chronic diseases (− 45.3%). They were also more proactive (+ 13.4%) in contacting their chronic patients compared to their peers practicing outside MGP. Conclusion We demonstrate that the MGP organisational formula was beneficial to the follow-up of patients with chronic conditions during the lockdown; therefore, it appears beneficial to expand integrated practices, since they perform better when facing a major shock. Further research is needed to confirm the efficiency of these integrated practices outside the particular pandemic setup.

  • Open Access English
    Authors: 
    Vimbiso Chidoti; Hélène De Nys; Valérie Pinarello; Getrude Mashura; Dorothée Missé; Laure Guerrini; Davies Pfukenyi; Julien Cappelle; Ngoni Chiweshe; Ahidjo Ayouba; +5 more
    Publisher: Preprints
    Country: France
    Project: ANR | MUSE (ANR-16-IDEX-0006)

    International audience; Background: Studies have linked bats to outbreaks of viral diseases in human populations such as SARS-CoV-1 and MERS-CoV and the ongoing SARS-CoV-2 pandemic. Methods: We carried out a longitudinal survey from August 2020 to July 2021 at two sites in Zimbabwe with bat–human interactions: Magweto cave and Chirundu farm. A total of 1732 and 1866 individual bat fecal samples were collected, respectively. Coronaviruses and bat species were amplified using PCR systems. Results: Analysis of the coronavirus sequences revealed a high genetic diversity, and we identified different sub-viral groups in the Alphacoronavirus and Betacoronavirus genus. The established sub-viral groups fell within the described Alphacoronavirus sub-genera: Decacovirus, Duvinacovirus, Rhinacovirus, Setracovirus and Minunacovirus and for Betacoronavirus sub-genera: Sarbecoviruses, Merbecovirus and Hibecovirus. Our results showed an overall proportion for CoV positive PCR tests of 23.7% at Chirundu site and 16.5% and 38.9% at Magweto site for insectivorous bats and Macronycteris gigas, respectively. Conclusions: The higher risk of bat coronavirus exposure for humans was found in December to March in relation to higher viral shedding peaks of coronaviruses in the parturition, lactation and weaning months of the bat populations at both sites. We also highlight the need to further document viral infectious risk in human/domestic animal populations surrounding bat habitats in Zimbabwe.

  • Open Access English
    Authors: 
    Emma Hubert; Thibaut Mastrolia; Dylan Possamaï; Xavier Warin;
    Publisher: HAL CCSD
    Countries: United States, France
    Project: ANR | PACMAN (ANR-16-CE05-0027)

    In this work, we provide a general mathematical formalism to study the optimal control of an epidemic, such as the COVID-19 pandemic, via incentives to lockdown and testing. In particular, we model the interplay between the government and the population as a principal-agent problem with moral hazard, à la Cvitanić et al. (Finance Stoch 22(1):1-37, 2018), while an epidemic is spreading according to dynamics given by compartmental stochastic SIS or SIR models, as proposed respectively by Gray et al. (SIAM J Appl Math 71(3):876-902, 2011) and Tornatore et al. (Phys A Stat Mech Appl 354(15):111-126, 2005). More precisely, to limit the spread of a virus, the population can decrease the transmission rate of the disease by reducing interactions between individuals. However, this effort-which cannot be perfectly monitored by the government-comes at social and monetary cost for the population. To mitigate this cost, and thus encourage the lockdown of the population, the government can put in place an incentive policy, in the form of a tax or subsidy. In addition, the government may also implement a testing policy in order to know more precisely the spread of the epidemic within the country, and to isolate infected individuals. In terms of technical results, we demonstrate the optimal form of the tax, indexed on the proportion of infected individuals, as well as the optimal effort of the population, namely the transmission rate chosen in response to this tax. The government's optimisation problems then boils down to solving an Hamilton-Jacobi-Bellman equation. Numerical results confirm that if a tax policy is implemented, the population is encouraged to significantly reduce its interactions. If the government also adjusts its testing policy, less effort is required on the population side, individuals can interact almost as usual, and the epidemic is largely contained by the targeted isolation of positively-tested individuals.

  • Open Access English
    Authors: 
    Tubaro, Paola; Casilli, Antonio,;
    Publisher: HAL CCSD
    Country: France
    Project: ANR | HUSH (ANR-19-CE10-0012)

    International audience; In this paper, we analyze the recessionary effects of the COVID-19 pandemic on digital platform workers. The crisis has been described as a great work-from-home experiment, with platform ecosystems positing as its most advanced form. Our analysis differentiates the direct (health) and indirect (economic) risks incurred by workers, to critically assess the portrayal of platforms as buffers against crisis-induced layoffs. We submit that platform-mediated labor may eventually increase precarity, without necessarily reducing health risks for workers. Our argument is based on a comparison of the three main categories of platform work – “on-demand labor” (gigs such as delivery and transportation), “online labor” (tasks performed remotely, such as data annotation) and “social networking labor” (content generation and moderation). We discuss the strategies that platforms deploy to transfer risk from clients onto workers, thus deepening existing power imbalances between them. These results question the problematic equivalence between work-from-home and platform labor. Instead of attaining the advantages of the former in terms of direct and indirect risk mitigation, an increasing number of platformized jobs drift toward high economic and insuppressible health risks.

  • Open Access English
    Authors: 
    Laura Di Domenico; Giulia Pullano; Chiara E. Sabbatini; Pierre-Yves Boëlle; Vittoria Colizza;
    Publisher: HAL CCSD
    Country: France
    Project: ANR | DataRedux (ANR-19-CE46-0008), ANR | SPHINx (ANR-17-CE36-0008), EC | MOOD (874850)

    As countries in Europe implement strategies to control the COVID-19 pandemic, different options are chosen regarding schools. Through a stochastic age-structured transmission model calibrated to the observed epidemic in Île-de-France in the first wave, we explored scenarios of partial, progressive, or full school reopening. Given the uncertainty on children’s role, we found that reopening schools after lockdown may increase COVID-19 cases, yet protocols exist to keep the epidemic controlled. Under a scenario with stable epidemic activity if schools were closed, reopening pre-schools and primary schools would lead to up to 76% [67, 84]% occupation of ICU beds if no other school level reopened, or if middle and high schools reopened later. Immediately reopening all school levels may overwhelm the ICU system. Priority should be given to pre- and primary schools allowing younger children to resume learning and development, whereas full attendance in middle and high schools is not recommended for stable or increasing epidemic activity. Large-scale test and trace is required to keep the epidemic under control. Ex-post assessment shows that progressive reopening of schools, limited attendance, and strong adoption of preventive measures contributed to a decreasing epidemic after lifting the first lockdown. The role of children in the spread of COVID-19 is not fully understood, and the circumstances under which schools should be opened are therefore debated. Here, the authors demonstrate protocols by which schools in France can be safely opened without overwhelming the healthcare system.

  • Open Access English
    Authors: 
    Romain Marlin; Véronique Godot; Sylvain Cardinaud; Mathilde Galhaut; Severin Coleon; Sandra Zurawski; Nathalie Dereuddre-Bosquet; Mariangela Cavarelli; Anne-Sophie Gallouet; Pauline Maisonnasse; +28 more
    Publisher: HAL CCSD
    Country: France
    Project: ANR | IDMIT (ANR-11-INBS-0008), EC | TRANSVAC2 (730964), EC | EVAg (653316)

    Achieving sufficient worldwide vaccination coverage against SARS-CoV-2 will require additional approaches to currently approved viral vector and mRNA vaccines. Subunit vaccines may have distinct advantages when immunizing vulnerable individuals, children and pregnant women. Here, we present a new generation of subunit vaccines targeting viral antigens to CD40-expressing antigen-presenting cells. We demonstrate that targeting the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein to CD40 (αCD40.RBD) induces significant levels of specific T and B cells, with long-term memory phenotypes, in a humanized mouse model. Additionally, we demonstrate that a single dose of the αCD40.RBD vaccine, injected without adjuvant, is sufficient to boost a rapid increase in neutralizing antibodies in convalescent non-human primates (NHPs) exposed six months previously to SARS-CoV-2. Vaccine-elicited antibodies cross-neutralize different SARS-CoV-2 variants, including D614G, B1.1.7 and to a lesser extent B1.351. Such vaccination significantly improves protection against a new high-dose virulent challenge versus that in non-vaccinated convalescent animals. In this study, Marlin et al. provide insights into the potential use of subunit vaccines that induce a high level of protection against SARS-CoV-2 in animal models.

  • Open Access English
    Authors: 
    Andronico, Alessio; Tran Kiem, Cécile; Paireau, Juliette; Succo, Tiphanie; Bosetti, Paolo; Lefrancq, Noémie; Nacher, Mathieu; Djossou, Félix; Sanna, Alice; Flamand, Claude; +3 more
    Publisher: HAL CCSD
    Countries: United Kingdom, France
    Project: EC | RECoVER (101003589), ANR | INCEPTION (ANR-16-CONV-0005)

    While general lockdowns have proven effective to control SARS-CoV-2 epidemics, they come with enormous costs for society. It is therefore essential to identify control strategies with lower social and economic impact. Here, we report and evaluate the control strategy implemented during a large SARS-CoV-2 epidemic in June–July 2020 in French Guiana that relied on curfews, targeted lockdowns, and other measures. We find that the combination of these interventions coincided with a reduction in the basic reproduction number of SARS-CoV-2 from 1.7 to 1.1, which was sufficient to avoid hospital saturation. We estimate that thanks to the young demographics, the risk of hospitalisation following infection was 0.3 times that of metropolitan France and that about 20% of the population was infected by July. Our model projections are consistent with a recent seroprevalence study. The study showcases how mathematical modelling can be used to support healthcare planning in a context of high uncertainty. Identifying effective combinations of control measures in different populations is important for SARS-CoV-2 control. Here, the authors show that in French Guiana, which has a relatively young population, curfews and localised lockdowns appeared to contribute to reducing transmission.

  • Open Access English
    Authors: 
    Bertrand Achou; Philippe De Donder; Franca Glenzer; Minjoon Lee; Marie-Louise Leroux;
    Publisher: TSE Working Paper
    Country: France
    Project: SSHRC , ANR | CHESS (ANR-17-EURE-0010)

    COVID-19 outbreaks at nursing homes during the recent pandemic, which received ample media coverage, may have lasting negative impacts on individuals’ perceptions regarding ursing homes. We argue that this could have sizable and persistent implications for savings and long-term care policies. We first develop a theoretical model predicting that higher nurs- ing home aversion should induce higher savings and stronger support for policies subsidizing home care. We further document, based on a survey on Canadians in their 50s and 60s, that higher nursing home aversion is widespread: 72% of respondents are less inclined to enter a nursing home because of the pandemic. Consistent with our model, we find that the latter are much more likely to have higher intended savings for older age because of the pandemic. We also find that they are more likely to strongly support home care subsidies.

  • Open Access English
    Authors: 
    Romain Lévy; Peng Zhang; Paul Bastard; Karim Dorgham; Isabelle Melki; Alice Hadchouel; George C. Hartoularos; Bénédicte Neven; Martin Castelle; Charlotte Roy; +12 more
    Publisher: HAL CCSD
    Country: France
    Project: ANR | AABIFNCOV (ANR-20-CO11-0001)

    Significance Life-threatening COVID-19 pneumonia can be caused by rare inborn errors of type I interferon (IFN) immunity, or by autoantibodies neutralizing IFN-α2 or IFN-ω. In 2018, we reported a girl with critical influenza pneumonia due to inherited IRF9 deficiency, a component of the ISGF-3 transcription factor. We report the course of COVID-19 in the same patient. She was admitted on day 1 of upper respiratory tract infection with viremia. Administration of SARS-CoV-2–specific neutralizing monoclonal antibodies on day 2 prevented the development of pneumonia. SARS-CoV-2–specific monoclonal antibodies were sufficient to overcome a lack of ISGF-3– and IRF9-dependent type I and type III IFN immunity to the virus. They should be considered in selected children at high risk of life-threatening COVID-19. We describe an unvaccinated child at risk for life-threatening COVID-19 due to an inherited deficiency of IRF9, which governs ISGF-3–dependent responses to type I and III interferons (IFN). She was admitted, with a high nasal SARS-CoV-2 load on day 1 of upper respiratory tract infection. She was viremic on day 2 and received casirivimab and imdevimab. Her clinical manifestations and viremia disappeared on days 3 and 4, respectively. Circulating SARS-CoV-2 virus induced the expression of IFN-stimulated genes in leukocytes on day 1, whereas the secretion of blood type I IFNs, which peaked on day 4, did not. Antibody-mediated SARS-CoV-2 neutralization is, therefore, sufficient to overcome a deficiency of antiviral IFNs.

  • Open Access English
    Authors: 
    Fortuna Casoria; Fabio Galeotti; Marie Claire Villeval;
    Publisher: HAL CCSD
    Country: France
    Project: ANR | DISTANCING (ANR-20-COVI-0054), ANR | CORTEX (ANR-11-LABX-0042), ANR | IDEXLYON (ANR-16-IDEX-0005)

    In response to the pandemic of COVID-19 and in lack of pharmaceutical solutions, many countries have introduced social and physical distancing regulations to contain the transmission of the virus. These measures are effective insofar as they are able to quickly change people's habits. This is achieved by changing the monetary incentives of rule violators but also by shifting people's perception regarding the appropriateness of socialization. We studied the effect of introducing, and then lifting, distancing regulations on the perceived norm regarding social encounters. We conducted an online incentivized experiment in France where we elicited the same participants' perceived norm and social distancing behavior every week for three months. We found that people shifted behavior and norm perception as soon as the government introduced or removed distancing measures. This effect was fast acting and long lasting. This is informative for future interventions, especially in light of a possible COVID-19 recurrence.