10.31234/osf.io/qhgrd

As the health and economic impact of Coronavirus Disease (COVID-19) expands globally, growing attention is being paid to low-or lower-middle-income countries due to high population densities, limited access to health-case-service, and existing financial burdens. Yet, literature on the psychological reaction to COVID-19 pandemic in low- or lower-middle-income countries is still limited. In this study, we examined people’s awareness of COVID-19 symptoms, perceived risk of contracting coronavirus, fear in response to the COVID-19 pandemic, and changes in behaviors and stress during the lockdown in peri-urban areas in Tamil Nadu India. Field workers conducted rapid phone call surveys (N=2044) in 26 communities from May 20th – 25th 2020. We found that the majority of the residents in our sampled community perceived no (60%) or low (23%) level of risk of personally contracting coronavirus. Common fears were related to both the health and economic impact of the pandemic, including loss of income (62%), inability to travel freely (46%), self might get sick (46%), and food shortage (39%). Residents were well-aware of the common symptoms of COVID-19, such as fever (66%) and dry cough (57%), but only a small proportion (24%) mentioned the asymptomatic features of COVID-19. A considerable proportion reported that they did not increase their practice of preventive behaviors since the lockdown, which included not reducing social gatherings (26%), not increasing social distancing practices (19%), and not inform others of COVID-19 related facts (30%). The majority experienced increased stress about finance (79%) and about the lockdown (51%). Our findings emphasize the need to develop context-adequate education and communication programs aimed to raise vigilance about coronavirus, specifically focused on factors such as its asymptomatic features, and to sustain preventive behaviors. The evidence on fear and changes in stress levels may serve as a reference in designing coping strategies and programs with a focus on mental well-being.

Awareness, risk perception, and stress during the COVID-19 pandemic in communities of Tamil Nadu, India

10.31234/osf.io/shm8v

Due to the strong overreliance on p-values in the scientific literature some researchers have argued that p-values should be abandoned or banned, and that we need to move beyond p-values and embrace practical alternatives. When proposing alternatives to p-values statisticians often commit the ‘Statistician’s Fallacy’, where they declare which statistic researchers really ‘want to know’. Instead of telling researchers what they want to know, statisticians should teach researchers which questions they can ask. In some situations, the answer to the question they are most interested in will be the p-value. As long as null-hypothesis tests have been criticized, researchers have suggested to include minimum-effect tests and equivalence tests in our statistical toolbox, and these tests (even though they return p-values) have the potential to greatly improve the questions researchers ask. It is clear there is room for improvement in how we teach p-values. If anyone really believes p-values are an important cause of problems in science, preventing the misinterpretation of p-values by developing better evidence-based education and user-centered statistical software should be a top priority. Telling researchers which statistic they should use has distracted us from examining more important questions, such as asking researchers what they want to know when they do scientific research. Before we can improve our statistical inferences, we need to improve our statistical questions.

The practical alternative to the p-value is the correctly used p-value

The average number of people one person with an infectious disease will likely infect

R number

The outbreak of novel coronavirus disease 2019 (COVID-19) has become a pandemic. Drug repurposing may represent a rapid way to fill the urgent need for effective treatment. We evaluated the clinical utility of chloroquine and hydroxychloroquine in treating COVID-19. Forty-eight patients with moderate COVID-19 were randomized to oral treatment with chloroquine (1000 mg QD on Day 1, then 500 mg QD for 9 days; n=18), hydroxychloroquine (200 mg BID for 10 days; n=18), or control treatment (n=12). Adverse events were mild, except for one case of Grade 2 ALT elevation. Adverse events were more commonly observed in the chloroquine group (44.44%) and the hydroxychloroquine group (50.00%) than in the control group (16.67%). The chloroquine group achieved shorter time to clinical recovery (TTCR) than the control group (P=0.019). There was a trend toward reduced TTCR in the hydroxychloroquine group (P=0.049). The time to reach viral RNA negativity was significantly faster in the chloroquine group and the hydroxychloroquine group than in the control group (P=0.006 and P=0.010, respectively). The median numbers of days to reach RNA negativity in the chloroquine, hydroxychloroquine, and control groups was 2.5 (IQR: 2.0-3.8) days, 2.0 (IQR: 2.0-3.5) days, and 7.0 (IQR: 3.0-10.0) days, respectively. The chloroquine and hydroxychloroquine groups also showed trends toward improvement in the duration of hospitalization and findings on lung computerized tomography (CT). This study provides evidence that (hydroxy)chloroquine may be used effectively in treating moderate COVID-19 and supports larger trials.

10.1101/2020.06.19.20136093

Efficacy and safety of chloroquine or hydroxychloroquine in moderate type of COVID-19: a prospective open-label randomized controlled study

The White House coronavirus task force has been out of public view as President Donald Trump has shown an urgency to move past the pandemic, downplay recent surges in Covid cases in some states, and get Americans back to work.But the nation's top infectious disease expert, Dr. Anthony Fauci, has been warning Americans about the risk of further spread of the virus. On Wednesday, Fauci, the director of the National Institute of Allergy and Infectious Diseases, joined the US Department of Health and Human Services' podcast "Learning Curve" and gave his expertise on the pandemic and the vaccine development process.He also defended the stay-at-home orders as having saved "millions of lives," and drew attention to anti-science bias and the disproportionate impact the virus is having on the black community.

Fauci warns of 'anti-science bias' being a problem in US

Governors promise to put kids back in class in a matter of weeks, but school officials are largely stuck navigating the messy details.

‘It’s just way too much to take on’: School systems struggle with the politics of reopening

As much of the country presses forward with reopening, a growing number of cities and states are finding that the coronavirus outbreak now has a foothold in a younger slice of the population, with people in their 20s and 30s accounting for a larger share of new coronavirus infections. The demographic shift has emerged in regions with different populations and political approaches to the pandemic – from Washington state and California to Florida and Texas. North Carolina, South Carolina, Arizona, Wisconsin and Colorado also all report clusters that have a larger proportion of young adults than they had previously seen.

Younger Adults Are Increasingly Testing Positive For The Coronavirus

A study in the UK has suggested a link between 5G Covid-19 conspiracy beliefs and the justification of violence.

Researchers link anger and paranoia with 5G Covid-19 conspiracy beliefs

An analysis from the U.S. Centers for Disease Control and Prevention of over a million coronavirus cases in the U.S. puts new numbers behind previous observations that the disease "disproportionately" affects racial and ethnic minority groups in the United States, as well as older people and those with underlying health conditions.

55% Of U.S. Coronavirus Cases In CDC Analysis Are Black And Hispanic

What is already known about this topic? Surveillance data reported to CDC through April 2020 indicated that COVID-19 leads to severe outcomes in older adults and those with underlying health conditions. What is added by this report? As of May 30, 2020, among COVID-19 cases, the most common underlying health conditions were cardiovascular disease (32%), diabetes (30%), and chronic lung disease (18%). Hospitalizations were six times higher and deaths 12 times higher among those with reported underlying conditions compared with those with none reported. What are the implications for public health practice? Surveillance at all levels of government, and its continued modernization, is critical for monitoring COVID-19 trends and identifying groups at risk for infection and severe outcomes. These findings highlight the continued need for community mitigation strategies, especially for vulnerable populations, to slow COVID-19 transmission.

Coronavirus Disease 2019 Case Surveillance — United States, January 22–May 30, 2020

We report cellular nanosponges as an effective medical countermeasure to the SARS-CoV-2 virus. Two types of cellular nanosponges are made of the plasma membranes derived from human lung epithelial type II cells or human macrophages. These nanosponges display the same protein receptors, both identified and unidentified, required by SARS-CoV-2 for cellular entry. It is shown that, following incubation with the nanosponges, SARS-CoV-2 is neutralized and unable to infect cells. Crucially, the nanosponge platform is agnostic to viral mutations and potentially viral species, as well. As long as the target of the virus remains the identified host cell, the nanosponges will be able to neutralize the virus.

10.1021/acs.nanolett.0c02278

Cellular Nanosponges Inhibit SARS-CoV-2 Infectivity

10.1101/2020.06.13.20130252

Background It is to be determined whether people infected with SARS-CoV-2 will develop long-term immunity against SARS-CoV-2 and retain long-lasting protective antibodies after the infection is resolved. This study was to explore to explore the outcomes of IgG antibodies to SARS-CoV-2 in four groups of individuals in Wuhan, China. Methods We included the following four groups of individuals who received both COVID-19 IgM/IgG tests and RT-PCR tests for SARS-CoV-2 from February 29, 2020 to April 29, 2020: 1470 hospitalized patients with COVID-19 from Leishenshan Hospital, Zhongnan Hospital of Wuhan University, and Wuhan No. 7 Hospital, 3832 healthcare providers without COVID-19 diagnosis, 19555 general workers, and 1616 other patients to be admitted to the hospital (N=26473). COVID-19 patients who received IgM/IgG tests <21 days after symptom onset were excluded. Results IgG prevalence was 89.8% (95% CI 88.2-91.3%) in COVID-19 patients, 4.0% (95% CI 3.4-4.7%) in healthcare providers, 4.6 (95% CI 4.3-4.9 %) in general workers, and 1.0% in other patients (p all <0.001 for comparisons with COVID-19 patients). IgG prevalence increased significantly by age among healthcare workers and general workers. Prevalence of IgM antibodies to SARS-CoV-2 was 31.4% in COVID-19 patients, 1.5% in healthcare providers, 1.3% in general workers, and 0.2% in other patients. Conclusions Very few healthcare providers had IgG antibodies to SARS-CoV-2, though a significant proportion of them had been infected with the virus. After SARS-CoV-2 infection, people are unlikely to produce long-lasting protective antibodies against this virus.

Prevalence of IgG antibodies to SARS-CoV-2 in Wuhan - implications for the ability to produce long-lasting protective antibodies against SARS-CoV-2

10.1038/s41591-020-0962-9

The COVID-19 pandemic has shown a markedly low proportion of cases among children1,2,3,4. Age disparities in observed cases could be explained by children having lower susceptibility to infection, lower propensity to show clinical symptoms or both. We evaluate these possibilities by fitting an age-structured mathematical model to epidemic data from China, Italy, Japan, Singapore, Canada and South Korea. We estimate that susceptibility to infection in individuals under 20 years of age is approximately half that of adults aged over 20 years, and that clinical symptoms manifest in 21% (95% credible interval: 12–31%) of infections in 10- to 19-year-olds, rising to 69% (57–82%) of infections in people aged over 70 years. Accordingly, we find that interventions aimed at children might have a relatively small impact on reducing SARS-CoV-2 transmission, particularly if the transmissibility of subclinical infections is low. Our age-specific clinical fraction and susceptibility estimates have implications for the expected global burden of COVID-19, as a result of demographic differences across settings. In countries with younger population structures—such as many low-income countries—the expected per capita incidence of clinical cases would be lower than in countries with older population structures, although it is likely that comorbidities in low-income countries will also influence disease severity. Without effective control measures, regions with relatively older populations could see disproportionally more cases of COVID-19, particularly in the later stages of an unmitigated epidemic

Age-dependent effects in the transmission and control of COVID-19 epidemics

10.1038/s41591-020-0965-6

The clinical features and immune responses of asymptomatic individuals infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have not been well described. We studied 37 asymptomatic individuals in the Wanzhou District who were diagnosed with RT–PCR-confirmed SARS-CoV-2 infections but without any relevant clinical symptoms in the preceding 14 d and during hospitalization. Asymptomatic individuals were admitted to the government-designated Wanzhou People’s Hospital for centralized isolation in accordance with policy1. The median duration of viral shedding in the asymptomatic group was 19 d (interquartile range (IQR), 15–26 d). The asymptomatic group had a significantly longer duration of viral shedding than the symptomatic group (log-rank P = 0.028). The virus-specific IgG levels in the asymptomatic group (median S/CO, 3.4; IQR, 1.6–10.7) were significantly lower (P = 0.005) relative to the symptomatic group (median S/CO, 20.5; IQR, 5.8–38.2) in the acute phase. Of asymptomatic individuals, 93.3% (28/30) and 81.1% (30/37) had reduction in IgG and neutralizing antibody levels, respectively, during the early convalescent phase, as compared to 96.8% (30/31) and 62.2% (23/37) of symptomatic patients. Forty percent of asymptomatic individuals became seronegative and 12.9% of the symptomatic group became negative for IgG in the early convalescent phase. In addition, asymptomatic individuals exhibited lower levels of 18 pro- and anti-inflammatory cytokines. These data suggest that asymptomatic individuals had a weaker immune response to SARS-CoV-2 infection. The reduction in IgG and neutralizing antibody levels in the early convalescent phase might have implications for immunity strategy and serological surveys.

Clinical and immunological assessment of asymptomatic SARS-CoV-2 infections

Objective To assess the clinical effectiveness of oral hydroxychloroquine (HCQ) with or without azithromycin (AZI) in preventing death or leading to hospital discharge. Design Retrospective cohort study. Setting An analysis of data from electronic medical records and administrative claim data from the French Assistance Publique - Hopitaux de Paris (AP-HP) data warehouse, in 39 public hospitals, Ile-de-France, France. Participants All adult inpatients with at least one PCR-documented SARS-CoV-2 RNA from a nasopharyngeal sample between February 1st, 2020 and April 6th, 2020 were eligible for analysis. The study population was restricted to patients who did not receive COVID-19 treatments assessed in ongoing trials, including antivirals and immunosuppressive drugs. End of follow-up was defined as the date of death, discharge home, day 28 after admission, whichever occurred first, or administrative censoring on May 4, 2020. Intervention Patients were further classified into 3 groups: (i) receiving HCQ alone, (ii) receiving HCQ together with AZI, and (iii) receiving neither HCQ nor AZI. Exposure to a HCQ/AZI combination was defined as a simultaneous prescription of the 2 treatments (more or less one day). Main outcome measures The primary outcome was all-cause 28-day mortality as a time-to-event endpoint under a competing risks survival analysis framework. The secondary outcome was 28-day discharge home. Augmented inverse probability of treatment weighted (AIPTW) estimates of the average treatment effect (ATE) were computed to account for confounding. Results A total of 4,642 patients (mean age: 66.1 +/- 18; males: 2,738 (59%)) were included, of whom 623 (13.4%) received HCQ alone, 227 (5.9%) received HCQ plus AZI, and 3,792 (81.7%) neither drug. Patients receiving "HCQ alone" or "HCQ plus AZI" were more likely younger, males, current smokers and overall presented with slightly more co-morbidities (obesity, diabetes, any chronic pulmonary diseases, liver diseases), while no major difference was apparent in biological parameters. After accounting for confounding, no statistically significant difference was observed between the "HCQ" and "Neither drug" groups for 28-day mortality: AIPTW absolute difference in ATE was +1.24% (-5.63 to 8.12), ratio in ATE 1.05 (0.77 to 1.33). 28-day discharge rates were statistically significantly higher in the "HCQ" group: AIPTW absolute difference in ATE (+11.1% [3.30 to 18.9]), ratio in ATE (1.25 [1.07 to 1.42]). As for the "HCQ+AZI" vs neither drug, trends for significant differences and ratios in AIPTW ATE were found suggesting higher mortality rates in the former group (difference in ATE +9.83% [-0.51 to 20.17], ratio in ATE 1.40 [0.98 to 1.81];p=0.062). Conclusions Using a large non-selected population of inpatients hospitalized for COVID-19 infection in 39 hospitals in France and robust methodological approaches, we found no evidence for efficacy of HCQ or HCQ combined with AZI on 28-day mortality. Our results suggested a possible excess risk of mortality associated with HCQ combined with AZI, but not with HCQ alone. Significantly higher rates of discharge home were observed in patients treated by HCQ, a novel finding warranting further confirmation in replicative studies. Altogether, our findings further support the need to complete currently undergoing randomized clinical trials.

10.1101/2020.06.16.20132597

Hydroxychloroquine with or without azithromycin and in-hospital mortality or discharge in patients hospitalized for COVID-19 infection: a cohort study of 4,642 in-patients in France

10.1111/bjso.12394

Amid increased acts of violence against telecommunication engineers and property, this pre‐registered study (N  = 601 Britons) investigated the association between beliefs in 5G COVID‐19 conspiracy theories and the justification and willingness to use violence. Findings revealed that belief in 5G COVID‐19 conspiracy theories was positively correlated with state anger, which in turn, was associated with a greater justification of real‐life and hypothetical violence in response to an alleged link between 5G mobile technology and COVID‐19, alongside a greater intent to engage in similar behaviours in the future. Moreover, these associations were strongest for those highest in paranoia. Furthermore, we show that these patterns are not specific to 5G conspiratorial beliefs: General conspiracy mentality was positively associated with justification and willingness for general violence, an effect mediated by heightened state anger, especially for those most paranoid in the case of justification of violence. Such research provides novel evidence on why and when conspiracy beliefs may justify the use of violence.

Pylons ablaze: Examining the role of 5G COVID‐19 conspiracy beliefs and support for violence

10.31234/osf.io/enzbv

In the wake of the Coronavirus Disease 2019 (COVID-19), social distancing has become important for containing the pandemic and preventing a renewed spread of the virus. We investigated psychological factors that predict adherence to social distancing guidelines. In a two-part longitudinal study (N = 574), we assessed adherence and its difficulty twice, one week apart. At T1, participants either planned to deal with the difficulties of adherence (planning intervention) or not (control condition). We further measured individual differences in planning, self-control, and boredom. T2 adherence was higher in the planning intervention, when participants intended to use plans. Trait planning was associated with higher T1 and T2 adherence and mitigated negative effects of T1 difficulty. Analogous effects emerged for trait self-control at T1. Trait boredom was associated with higher difficulty at T1 and T2 without directly affecting adherence. Our results are relevant for designing effective measures in prolonged responses to COVID-19.

Boredom makes it difficult, but it helps to have a plan: Investigating adherence to social distancing guidelines during the COVID-19 pandemic

As public scrutiny of a secretive panel of scientists heightened, its members nearly buckled under the strain.

For Boris Johnson’s Science Advisers, Pressure, Anxieties and ‘Pastoral Support’

As states ease their lockdowns, bars are emerging as fertile breeding grounds for the coronavirus. They create a risky cocktail of tight quarters, young adults unbowed by the fear of illness and, in some instances, proprietors who don’t enforce crowd limits and social distancing rules. Public health authorities have identified bars as the locus of outbreaks in Louisiana, Florida, Wyoming and Idaho. Last weekend, the Texas alcohol licensing board suspended the liquor licenses of 17 bars after undercover agents observed crowds flouting emergency rules that required patrons to keep a safe distance from one another and limit tavern occupancy.

Packed Bars Serve Up New Rounds Of COVID Contagion

Openness in research can lead to greater reproducibility, an accelerated pace of discovery, and decreased redundancy of effort. In addition, open research ensures equitable access to knowledge and the ability for any community to assess, interrogate, and build upon prior work. It also requires open infrastructure and distributed access; but few institutions can provide all of these services alone. Providing a trustworthy network for perpetual availability of research data is critical to ensuring reproducibility, transparency, and ongoing inquiry. Increased attention on the importance of open research and data sharing has led to a proliferation of platforms to store data, materials, etc., with limited technical integration. This can hinder data sharing, but also complicate coordination with local library expertise and services, thus hampering curation and long-term stewardship. For example, the open source OSF enables researchers to directly create and manage research projects and integrates with other tools researchers use (Google Drive, Dropbox, Box, etc.), but lacks the ability to archive that material locally at a researcher’s institution. Long-term stewardship and preservation requires multiple copies of data archived in different locations, and creating archives seamlessly would be ideal. COS and IA are working together to address these preservation and stewardship challenges by providing open, cooperative infrastructure to ensure long-term access and connection to research data, and by supporting and promoting adoption of open science practices to enhance research reproducibility as well as data sharing and reuse. In this webinar, attendees will learn about both the technical and practical aspects of this collaborative project connecting the researcher tool OSF and the preservation system of Internet Archive. We demonstrate how researchers can improve the openness and reproducibility of their research through preregistration, and how those preregistrations are preserved with Internet Archive. We answer questions and explore use cases for how this powerful workflow can support library curation and stewardship of open research.

Supporting Open Science Data Curation, Preservation, and Access by Libraries

Openness in research can lead to greater reproducibility, an accelerated pace of discovery, and decreased redundancy of effort. In addition, open research ensures equitable access to knowledge and the ability for any community to assess, interrogate, and build upon prior work. It also requires open infrastructure and distributed access; but few institutions can provide all of these services alone. Providing a trustworthy network for perpetual availability of research data is critical to ensuring reproducibility, transparency, and ongoing inquiry. Increased attention on the importance of open research and data sharing has led to a proliferation of platforms to store data, materials, etc., with limited technical integration. This can hinder data sharing, but also complicate coordination with local library expertise and services, thus hampering curation and long-term stewardship. COS and IA are working together to address these preservation and stewardship challenges by providing open, cooperative infrastructure to ensure long-term access and connection to research data, and by supporting and promoting adoption of open science practices to enhance research reproducibility as well as data sharing and reuse. In this webinar, attendees will learn about both the technical and practical aspects of this collaborative project connecting the researcher tool OSF and the preservation system of Internet Archive. We will demonstrate how researchers can improve the openness and reproducibility of their research through preregistration, and how those preregistrations are preserved with Internet Archive. We will answer questions and seek to learn your needs and use cases for how this powerful workflow can support library curation and stewardship of open research.

Supporting Open Science Data Curation, Preservation, and Access by Libraries

In mid-May, Arizona Governor Doug Ducey ended the state's stay-at-home order and proclaimed the state ready for "the next stage of economic recovery." Little more than a month later, that recovery is under serious strain as local coronavirus cases spike, causing some reopened businesses to close again and consumers to retreat homeward. States now seeing explosive growth in coronavirus cases are also taking an economic hit, with indicators such as restaurant bookings, consumer spending and small business activity pointing to a slowdown, according to Deutsche Bank economists. Those states include Arizona, South Carolina and Texas, all of which pushed to reopen their economies quickly. Texas, which had one of the shortest stay-at-home orders in the country, on Thursday announced a halt to its reopening plan, citing the surge in COVID-19 cases.

Coronavirus surge in states that rushed to reopen is hurting economic growth

Video & Podcast: Tracking and enabling new possibilities

[Virtual] The Pandemic As a Portal

In this webinar, chaired by the University of Warwick’s Provost, Professor Christine Ennew, you will hear from two of the University's leading researchers in Behavioural Science and Public Health, who discuss the global response to Covid-19, the many lessons learnt, and how Warwick is best placed to lead a new research institute focused on preparing the world for future pandemics.

The Institute for Global Pandemic Planning: Developing a Warwick Response to Covid-19

in other words: overestimation of familiar risks makes COVID-19 seems much less of an outlier, and much more like background 'everyday risk' than it is which would explain why so many otherwise smart (but non JDM) people I see keep churning out that phrase

But (=lightbulb moment) these two things are entirely compatible, because that over-estimation means that the many non-COVID daily risks of death people are faced with, are assumed to be much more prevalent (driving, flying etc)- and, "experience" suggests we can live with those

(to which I've replied, like a broken record, and you think that's LOW"?) ..this has sat uneasily with the one thing we all think we know, namely that people are supposed to be unduly freaked by really low probability events, because they robustly overestimated low probabilities

Fellow behavioural scientists, I had a lightbulb moment yesterday. I suspect I might have been unusually slow here, and you all clocked this months ago, but thought I'd share nevertheless: I've lost count of how often I've been told "You only have a 1/100 chance of dying"

Coming out soon in @terpolv! I'm very excited about the release of this study. Years in the making.

You’re listening to a press conference from the Harvard T.H. Chan School of Public Health featuring Marc Lipsitch, professor of epidemiology and director of the School’s Center for Communicable Disease Dynamics. This call was recorded at 11:30 am Eastern Time on Wednesday, March 4. 

Coronavirus (COVID-19): Press Conference with Marc Lipsitch, 03/04/20

Unfortunately, uncertainties in variation in contact rates and susceptibility/infectiousness will prevent us from ever having precise value for HIT for 1 pop & it will vary among populations (as does R0). The take home message is want to get to HIT by vaccination NOT infection.

Together papers suggest herd immunity thresh is <1-1/R0 and epidemic overshoot <f=1-exp(-(f*R0)), but by how much is still unknown. Ugh. @mlipsitch smartly gave a wide range 40-70% (20-60% in later interviews) for fraction infected f w/out interventions.

Serological data from NYC suggest that either heterogeneity estimate is too large or R0 is much larger, or lockdown did nothing to stop outbreak as seroprevalence is already at overhsoot epidemic size f (~20% - I added horiz dashed line).

I'd like to see uncertainty around those estimates of heterogeneity & some are very indirect estimates, but range of values is much better than arbitrarily chosen numbers and suggest heterogeneity is substantial. But ...

@mgmgomes1 paper is much better in providing empirical estimates of heterogeneity & impacts on HIT, f based on data (colored lines in figure).

What I find puzzling is that this paper is in Science. It's a extremely simple modeling exercise, with arbitrarily chosen parameter values. It isn't as general as @mgmgomes1 paper cited above, and it's not clear it has any new empirical data. Many older papers say same thing.

The conclusion in the abstract is appropriately worded in making it clear that the paper is simply an illustration of a concept, not an actual estimate of the most likely value.

The take home of the science paper is that pops partially structured by age (i.e. NOT well-mixed) and w/ arbitrary differential "activity" (contact rates) w/in ages can reduce HIT for R0=2.5 from 0.6 to 0.43.

The strange part is that it's not clear what source their age-mixing data comes from. The citation they give is NOT a published paper - it's a link to a page w/ Matlab files. It's weird because there are several age-mixing datasets out there. @sbfnk can probably provide best ones

Science paper (link above) also shows how reasonable variation in contact rates among individuals reduces HIT. It considers differential mixing among age groups and hypothetical variation among individuals w/in each age group having more or fewer contacts.

However, see paper by @mgmgomes1 that is even better (b/c more general, better data) than Science paper cited above. Fig shows how variation susc, contacts affects HIT, f, for R0=3; so HIT=0.66, f = 0.94.

Positive correlations among these traits - if individuals w/ more contacts are more susceptible and infectious - can make for very rapid changes in dynamics. Sadly not much empirical data on these correlations & limited data on predictors of variation on susc. & infect.

1) If some individuals have few contacts then they are unlikely to be infected, lowering HIT. (note: variation in contacts can lead to faster early spread). 2) If some aren't susceptible to infection that reduces HIT. 3)If some people don't transmit that also reduces HIT.

Human populations are NOT WELL-MIXED & HOMOGENOUS, so calcs give likely upper bound. Q: So what is herd immunity threshold (HIT) for real pops? A: *Usually* lower & it depends on variation among individuals in 3 things: 1) contact rates; 2) susceptibility; 3) infectiousness.

These simple calculations & flu data are what led @mlipsitch to make early widely cited rough back of the envelope calculations that 40-70% of pop would get infected without interventions. Most articles cited the 70% *BUT* @mlipsitch knew that...

In idealized population, early vaccination to HIT will prevent outbreak b/c Rt=R0*S/N so Rt<1. However, an epidemic will overshoot HIT & infect larger fraction f of pop where f=1-exp(-(f*R0)). For R0=2.5 (reasonable for COVID19 in some pops), HIT=0.6, and f = 0.89.

Background: If we know reproductive number R0 for pathogen in population, herd immunity threshold (HIT) for WELL-MIXED HOMOGENOUS population is simply 1-1/R0. (Note R0 varies w/ behavior, host traits, environment so differs over time&space).

What is #herdimmunity threshold for #COVID19? A topic of much discussion due to large uncertainty & huge consequences for long term impact. New paper illustrates 1 key aspect that can reduce it substantially (spoiler: we still don't know value). Thread.

PurposeNew York State (NYS) is an epicenter of the SARS-CoV-2 pandemic in the United States. Reliable estimates of cumulative incidence in the population are critical to tracking the extent of transmission and informing policies.MethodsWe conducted a statewide seroprevalence study among a 15,101 patron convenience sample at 99 grocery stores in 26 counties throughout NYS. SARS-CoV-2 cumulative incidence was estimated from antibody reactivity by first post-stratification weighting then adjusting by antibody test characteristics. The percent diagnosed was estimated by dividing diagnoses by estimated infection-experienced adults.ResultsBased on 1,887 of 15,101 reactive results (12.5%), estimated cumulative incidence through March 29 was 14.0% (95% CI: 13.3-14.7%), corresponding to 2,139,300 (95% CI: 2,035,800-2,242,800) infection-experienced adults. Cumulative incidence was highest in New York City (NYC) 22.7% (95% CI: 21.5-24.0%) and higher among Hispanic/Latino (29.2%), non-Hispanic black/African American (20.2%), and non-Hispanic Asian (12.4%) than non-Hispanic white adults (8.1%, p<.0001). An estimated 8.9% (95% CI: 8.4-9.3%) of infections in NYS were diagnosed, with diagnosis highest among adults ≥55 years (11.3%, 95% CI: 10.4-12.2%).ConclusionsFrom the largest US serosurvey to date, we estimated > 2 million adult New York residents were infected through late March, with substantial disparities, although cumulative incidence remained below herd immunity thresholds. Monitoring, testing, and contact tracing remain essential public health strategies.

10.1016/j.annepidem.2020.06.004

Cumulative incidence and diagnosis of SARS-CoV-2 infection in New York

As severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spreads, the susceptible subpopulation is depleted causing the incidence of new cases to decline. Variation in individual susceptibility or exposure to infection exacerbates this effect. Individuals that are more susceptible or more exposed tend to be infected earlier, depleting the susceptible subpopulation of those who are at higher risk of infection. This selective depletion of susceptibles intensifies the deceleration in incidence. Eventually, susceptible numbers become low enough to prevent epidemic growth or, in other words, the herd immunity threshold (HIT) is reached. Although estimates vary, simple calculations suggest that herd immunity to SARS-CoV-2 requires 60-70% of the population to be immune. By fitting epidemiological models that allow for heterogeneity to SARS-CoV-2 outbreaks across the globe, we show that variation in susceptibility or exposure to infection reduces these estimates. Accurate measurements of heterogeneity are therefore of paramount importance in controlling the COVID-19 pandemic.

10.1101/2020.04.27.20081893

Individual variation in susceptibility or exposure to SARS-CoV-2 lowers the herd immunity threshold

Boston — The coronavirus death toll now tops 3,000 worldwide, with nearly 90,000 cases. But even those numbers are nothing compared to what could happen in the months ahead.CBS News spoke to one of the country's top experts on viruses, Marc Lipsitch from Harvard University, who cautions that 40-70% of the world's population will become infected — and from that number, 1% of people who get symptoms from COVID-19, the disease caused by the coronavirus, could die. The virus can spread rapidly and people can transmit it before they know they are infected.Lipsitch breaks down his findings in this extended conversation with CBS News. The following transcript has been lightly edited for clarity.

Coronavirus may infect up to 70% of world's population, expert warns

Based on current rate of daily case growth (which I est. at 3.4%), I am predicting that we will have 100k cases PER DAY on or around July 24 if we don’t do something drastic AND soon! Even with measures taken, we will almost certainly still achieve that level, though in August.

Democrats & Republicans have seemingly taken a divided stance on how to handle the #COVID19 pandemic, & their Twitter accounts might provide the best evidence to date. Watch the latest video from our #coronavirus series on research from @ScienceAdvances: https://fcld.ly/kp8s9er

10.1126/sciadv.abc2717

Cues sent by political elites are known to influence public attitudes and behavior. Polarization in elite rhetoric may hinder effective responses to public health crises, when accurate information and rapid behavioral change can save lives. We examine polarization in cues sent to the public by current members of the U.S. House and Senate during the onset of the COVID-19 pandemic, measuring polarization as the ability to correctly classify the partisanship of tweets’ authors based solely on the text and the dates they were sent. We find that Democrats discussed the crisis more frequently—emphasizing threats to public health and American workers, while Republicans placed greater emphasis on China and businesses. Polarization in elite discussion of the COVID-19 pandemic peaked in mid-February – weeks after the first confirmed case in the United States – and continued into March. These divergent cues correspond with a partisan divide in the public’s early reaction to the crisis.

Elusive consensus: Polarization in elite communication on the COVID-19 pandemic

10.1371/journal.pcbi.1007946

The scale and intensity of the coronavirus disease 2019 (COVID-19) worldwide pandemic is unprecedented in all our lifetimes. It has changed our lifestyles and our workstyles, in a manner and to a degree that is likely to persist for some time. Here we offer some guidance, in the familiar ten simple rules format, for how to navigate a stressful situation, considering it realistically as both a curse and an opportunity. This is written for all of us involved in scientific research—graduate student, postdoc, academic, staff scientist, in academia, government or industry. Each such person has so much to contribute in a time of need but is simultaneously also a member of a worldwide population under threat. What can one do in a time like this?

Ten simple rules for researchers while in isolation from a pandemic

#sfhphealthpolicycouncil Help protect at-risk populations from extreme heat during the COVID-19 Pandemic

10.31234/osf.io/3fnrh

Traditionally, handshaking has conferred benefits for businesspeople—signaling politeness, establishing an intention to cooperate, and promoting deal-making. How might the psychological meaning of handshaking have shifted due to the COVID-19 pandemic, which led handshaking to become touted as an imminent threat to public health? Through a highly powered, preregistered study (N = 595), we compared U.S. adults’ perceptions of a businessperson who shakes hands vs. refrains from shaking hands during the era of COVID-19. Participants judged handshakers more negatively than non-handshakers, in terms of both global attitude toward them (d = 2.21) and approval of their job performance (d = 2.66). Mediation analyses suggest that businesspeople were judged negatively for shaking hands principally because doing so made them seem less competent and less moral. Judgments of handshaking were more negative among liberals than conservatives and among women than men. To maximize others’ perceptions of them, it would behoove businesspeople to refrain from shaking hands for the foreseeable future. The months and years ahead may be an unprecedented time to rediscover the psychology of handshaking and its role in the workplace.

Judgments of Businesspeople Who Shake Hands in the Era of COVID-19