H5N1

WHO: Weekly epidemiological update on COVID-19 - 3 August 2023

WHO has published Weekly epidemiological update on COVID-19 - 3 August 2023. Click or tap through to download the complete report. The overview:

Globally, over one million new COVID-19 cases and over 3100 deaths were reported in the last 28 days (3 to 30 July 2023). While five WHO regions have reported decreases in the number of both cases and deaths, the Western Pacific Region has reported an increase in the number of cases and a decrease in the number of deaths. 

As of 30 July 2023, over 768 million confirmed cases and over 6.9 million deaths have been reported globally. Currently, reported cases do not accurately represent infection rates due to the reduction in testing and reporting globally. 

During this 28-day period, 46% (107 of 234) of countries and territories reported at least one case to WHO – a proportion that has been declining since mid-2022. 

In this edition, we include:  

• The COVID-19 epidemiological update at the global and the regional levels  

• An update on hospitalizations and ICU admissions  

• An update on the SARS-CoV-2 variants of interest (VOI) and variants under monitoring (VUM)  

• An update on the vaccine effectiveness of primary series and booster vaccination against the Omicron and its descendant lineages

Communication of COVID-19 misinformation on social media by physicians in the US

Via JAMA Network: Communication of COVID-19 Misinformation on Social Media by Physicians in the US. The key points and abstract:

Key Points  

Question  What types of COVID-19 misinformation have been propagated online by US physicians and through what channels?  

Findings  In this mixed-methods study of high-use social media platforms, physicians from across the US and representing a range of medical specialties were found to propagate COVID-19 misinformation about vaccines, treatments, and masks on large social media and other online platforms and that many had a wide reach based on number of followers.  

Meaning  This study’s findings suggest a need for rigorous evaluation of harm that may be caused by physicians, who hold a uniquely trusted position in society, propagating misinformation; ethical and legal guidelines for propagation of misinformation are needed.  

Abstract  

Importance  Approximately one-third of the more than 1 100 000 confirmed COVID-19–related deaths as of January 18, 2023, were considered preventable if public health recommendations had been followed. Physicians’ propagation of misinformation about COVID-19 on social media and other internet-based platforms has raised professional, public health, and ethical concerns.  

Objective  To characterize (1) the types of COVID-19 misinformation propagated by US physicians after vaccines became available, (2) the online platforms used, and (3) the characteristics of the physicians spreading misinformation.  

Design, Setting, and Participants  Using US Centers for Disease Control and Prevention guidelines for the prevention and treatment of COVID-19 infection during the study window to define misinformation, structured searches of high-use social media platforms (Twitter, Facebook, Instagram, Parler, and YouTube) and news sources (The New York Times, National Public Radio) were conducted to identify COVID-19 misinformation communicated by US-based physicians between January 2021 and December 2022. Physicians’ state of licensure and medical specialty were identified. The number of followers for each physician on 4 major platforms was extracted to estimate reach and qualitative content analysis of the messages was performed.  

Main Outcomes and Measures  Outcome measures included categories of COVID-19 misinformation propagated, the number and traits of physicians engaged in misinformation propagation, and the type of online media channels used to propagate misinformation and potential reach.  

Results  The propagation of COVID-19 misinformation was attributed to 52 physicians in 28 different specialties across all regions of the country. General misinformation categories included vaccines, medication, masks, and other (ie, conspiracy theories). Forty-two physicians (80.8%) posted vaccine misinformation, 40 (76.9%) propagated information in more than 1 category, and 20 (38.5%) posted misinformation on 5 or more platforms. Major themes identified included (1) disputing vaccine safety and effectiveness, (2) promoting medical treatments lacking scientific evidence and/or US Food and Drug Administration approval, (3) disputing mask-wearing effectiveness, and (4) other (unsubstantiated claims, eg, virus origin, government lies, and other conspiracy theories).  

Conclusions and Relevance  In this mixed-methods study of US physician propagation of COVID-19 misinformation on social media, results suggest widespread, inaccurate, and potentially harmful assertions made by physicians across the country who represented a range of subspecialties. Further research is needed to assess the extent of the potential harms associated with physician propagation of misinformation, the motivations for these behaviors, and potential legal and professional recourse to improve accountability for misinformation propagation.

The evolution of SARS-CoV-2 seroprevalence in Canada: A time-series study, 2020–2023

Via CMAJ: The evolution of SARS-CoV-2 seroprevalence in Canada: a time-series study, 2020–2023. The abstract:

Background: During the first year of the COVID-19 pandemic, the proportion of reported cases of COVID-19 among Canadians was under 6%. Although high vaccine coverage was achieved in Canada by fall 2021, the Omicron variant caused unprecedented numbers of infections, overwhelming testing capacity and making it difficult to quantify the trajectory of population immunity.  

Methods: Using a time-series approach and data from more than 900 000 samples collected by 7 research studies collaborating with the COVID-19 Immunity Task Force (CITF), we estimated trends in SARS-CoV-2 seroprevalence owing to infection and vaccination for the Canadian population over 3 intervals: prevaccination (March to November 2020), vaccine roll-out (December 2020 to November 2021), and the arrival of the Omicron variant (December 2021 to March 2023). We also estimated seroprevalence by geographical region and age.  

Results: By November 2021, 9.0% (95% credible interval [CrI] 7.3%–11%) of people in Canada had humoral immunity to SARS-CoV-2 from an infection. Seroprevalence increased rapidly after the arrival of the Omicron variant — by Mar. 15, 2023, 76% (95% CrI 74%–79%) of the population had detectable antibodies from infections. The rapid rise in infection-induced antibodies occurred across Canada and was most pronounced in younger age groups and in the Western provinces: Manitoba, Saskatchewan, Alberta and British Columbia.  

Interpretation: Data up to March 2023 indicate that most people in Canada had acquired antibodies against SARS-CoV-2 through natural infection and vaccination. However, given variations in population seropositivity by age and geography, the potential for waning antibody levels, and new variants that may escape immunity, public health policy and clinical decisions should be tailored to local patterns of population immunity.