News Scan for Feb 10, 2022

News brief

Previous COVID infection may confer 56% protection against reinfection

A study in Qatar estimates that previous COVID-19 infection imparts 56% protection against future symptomatic infection caused by the highly transmissible Omicron variant, down from about 90% for other SARS-CoV-2 strains.

The study, published yesterday in the New England Journal of Medicine (NEJM), was led by researchers at Weill Cornell Medicine–Qatar in Doha.

The team extracted data on COVID-19 testing, vaccination, clinical infections, outcomes, and demographics from national databases amid the Omicron surge.

The median interval between initial COVID-19 infection and polymerase chain reaction (PCR) testing of 5,696 positive cases and 10,673 negative controls was 279 days for analysis of the Alpha variant, 285 days for the Beta variant, 254 days for the Delta variant, and 314 days for Omicron.

Estimated effectiveness of a previous infection in preventing reinfection was 90.2% against Alpha, 85.7% against Beta, 92.0% against Delta, and 56.0% against Omicron. Sensitivity analyses that excluded vaccinated patients confirmed the results.

Among reinfected patients, one patient with the Alpha variant became severely ill, as did two each with Beta and Omicron, but no patients with Delta did so. No reinfection was critical or fatal. Estimated effectiveness against severe, critical, or fatal COVID-19 was 69.4% for Alpha, 88.0% for Beta, 100% with Delta, and 87.8% with Omicron.

"We found that the effectiveness of previous infection in preventing reinfection with the alpha, beta, and delta variants of SARS-CoV-2 was robust (at approximately 90%), findings that confirmed earlier estimates," the researchers concluded.

"Such protection against reinfection with the omicron variant was lower (approximately 60%) but still considerable," they added. "In addition, the protection of previous infection against hospitalization or death caused by reinfection appeared to be robust, regardless of variant."
Feb 9 NEJM research letter

Study: Third of US adults develop new symptoms post-COVID-19

Thirty-two percent of older adults who were diagnosed as having COVID-19 in 2020 developed a new symptom in the months following infection that required them to seek additional medical care, according to a study yesterday in BMJ.

The observational study was based on US health insurance plan records of 133,366 individuals aged 65 or older in 2020 who were diagnosed with COVID-19 before Apr 1, 2020. The cohort was matched and compared to adults from 2020 and 2019.

According to the authors, only 21% of non-COVID older adults from 2020 sought medical care during the same period, compared to 32% of adults with COVID-19; all medical care after 21 days of acute infection was included in the study.

Respiratory failure (risk difference 7.55, 95% confidence interval 7.18 to 8.01), fatigue (5.66, 5.03 to 6.27), hypertension (4.43, 2.27 to 6.37), memory difficulties (2.63, 2.23 to 3.13), kidney injury (2.59, 2.03 to 3.12), mental health diagnoses (2.50, 2.04 to 3.04), hypercoagulability (1.47,1.2 to 1.73), and cardiac rhythm disorders (2.19, 1.76 to 2.57) had the greatest risk differences compared with both the 2020 and 2019 comparison groups, the authors said.

Men, adults over 75, and Black COVID-19 patients were at the greater risk for developing new sequelae in the months following COVID-19 infection.

"These findings further highlight the wide range of important sequelae after acute infection with the SARS-CoV-2 virus," the authors concluded. "Understanding the magnitude of risk for the most important clinical sequelae might enhance their diagnosis and the management of individuals with sequelae after acute SARS-CoV-2 infection."
Feb 9 BMJ study

Launch of first human trial of Nipah virus vaccine announced

Public Health Vaccines (PHV), based in Massachusetts, yesterday announced the launch of a phase 1 clinical trial for its Nipah virus vaccine, the first of its kind to be tested in people.

The vaccine was developed by scientists at the National Institute of Allergy and Infectious Diseases, which licensed the product to PHV. The vaccine's development has been supported by the Coalition for Epidemic Preparedness Innovations (CEPI), which in 2017 flagged Nipah virus as one of four diseases that has the capability to trigger a major global epidemic.

The bat-borne virus can spread to both humans and livestock and can spread person-to-person. It is listed as a priority virus by the World Health Organization and as a category C bioterrorism agent by the US Centers for Disease Control and Prevention (CDC).

PHV's vaccine is a single-dose live, attenuated, recombinant vesicular stomatitis virus that expresses both the Nipah virus glycoprotein and the Ebola virus glycoprotein, which is required for receptor-based viral entry.

The phase 1 trial will assess safety, tolerability, and immunogenicity of three dose levels in 60 healthy adults in the United States. Pending favorable results, the company said in a news release that it will launch a phase 2 trial this year in a country where the disease is endemic.
Feb 9 PHV press release

CDC: Recent US H5N1 avian flu detections pose low threat to people

In the wake of recent highly pathogenic H5N1 avian flu detections in US waterfowl and the first related outbreak in poultry, the CDC said yesterday that the threat to the public remains low, but people who have greater exposure may have a heightened risk.

Recent sporadic H5 infections in people have been reported from abroad, including one in January in the United Kingdom in a patient who had close contact with poultry. Similar sporadic infections in the United States resulting from close contact with wild birds or poultry wouldn't be surprising and wouldn't change its risk assessment, the CDC added. Human-to-human spread of avian flu viruses is rare and hasn't led to sustained transmission.

The CDC said it has an existing candidate H5 vaccine virus that is nearly identical to the virus found recently in US wild bird samples, which could be used to make a vaccine for humans, if needed. It added that sequencing also suggests that the virus would be susceptible to current antiviral medications used to treat flu.
Feb 9 CDC statement
Feb 9 CIDRAP News story "H5N1 avian flu turns up in US poultry on Indiana turkey farm"

Stewardship / Resistance Scan for Feb 10, 2022

News brief

Study finds higher risk of group A Strep skin infections among homeless

A study conducted in San Francisco found that homeless residents were more than four times as likely to have group A Streptococcus (GAS) skin infections as people with stable housing, researchers reported yesterday in JAMA Dermatology.

The retrospective, cross-sectional study analyzed inpatients seen by dermatology services at two San Francisco hospitals for bacterial skin and other soft-tissue infections (SSTIs) from March 2018 through March 2020. Patients were classified as persons experiencing homelessness (PEH) if they reported no primary address or an institutional primary address within the past 12 months. Researchers used logistic regression to determine associations between housing status and both GAS SSTI and methicillin-resistant Staphylococcus aureus (MRSA) SSTI.

Of the 181 patients included in the study, 52 were PEH and 129 had stable housing. Among PEH, 42% had GAS-positive cultures and 33% had MRSA-positive cultures, compared with 15% and 23% of patients with stable housing, respectively. After controlling for confounders, PEH had significantly higher odds of GAS SSTI (odds ratio [OR], 4.25; 95% confidence interval [CI], 1.86 to 9.70; P = .001) and non-significantly higher odds of MRSA SSTI (OR, 1.49; 95% CI, 0.68 to 3.27; P = .33).

The analysis also found that PEH had significantly higher rates of first-line MRSA antibiotic coverage than patients with stable housing (90% vs 70%) and non-significantly reduced rates of first-line GAS coverage (30% vs 47%), a finding the study authors say suggests providers may prioritize MRSA among homeless patients presenting with SSTI.

"Given that 42% of PEH had cultures that tested positive for GAS and PEH had 4.25 times higher odds of GAS SSTI, the present study results suggest that health care professionals may need to consider GAS more strongly among PEH presenting with SSTI," they wrote.
Feb 9 JAMA Dermatol study

UK white paper suggests ways to transform infection management

A newly formed coalition of pharmaceutical and diagnostics companies and research organizations yesterday published a white paper with recommendations to transform the way infections are detected, monitored, managed, and prevented across all facets of England's National Health Service, with a focus on mitigating the harms from antimicrobial resistance (AMR).

The paper from the Infection Management Coalition (IMC) presents 29 recommendations to nurture a patient-centered, holistic approach to infection management and help achieve the UK government's 20-year vision of a world in which AMR is effectively contained. The groups say the recommendations support development of a roadmap that will help "accelerate the creation of a system which is resilient and mature with regard to: outbreak and pandemic preparedness; infection prevention; rapid recognition, diagnosis and treatment of time-critical viral and bacterial infections; and to, ultimately, deliver effective AMS [antimicrobial stewardship]."

The recommendations presented in the paper include the development and implementation of a data registry for patients entering the healthcare system with an infection that would track the medicines used and monitor outcomes and recovery, along with a requirement that clinicians input infection data into electronic patient records so that the systems know exactly which antibiotics work for patients.

The paper also calls for greater integration of point-of-care diagnostics; allowing sepsis, infection, and AMR to be registered as actual causes of death; development of more robust surveillance systems to track infections and resistant pathogens; creation of a 5-year national plan to explore development of new antibiotics and cutting-edge diagnostics; and establishing the "human face" of AMR.

"Infection is managed across all specialties in healthcare because it is common and has diverse implications," the paper states. "To address AMR and to maintain antimicrobial stewardship, we need to approach infection management holistically."
Feb 9 IMC white paper