News Scan for Dec 28, 2021

News brief

Fully vaccinated people with immune dysfunction at higher risk of breakthrough COVID

Full vaccination against COVID-19 was associated with reduced risk of breakthrough infection, but risk of breakthrough infection was much higher among fully vaccinated people with immune dysfunction than those without, US researchers reported today in JAMA Internal Medicine.

The retrospective cohort study analyzed data from the National COVID Cohort Collaborative, an electronic medical record-based repository of COVID-19 clinical data. The researchers included all patients who had received at least one dose of a COVID-19 vaccine from Dec 10, 2020, through Sep 16, 2021. Full vaccination was defined as completion of the recommended dosing regimen of any Food and Drug Administration authorized COVID-19 vaccine. Breakthrough infection was defined as a COVID-19 infection that was contracted on or after the 14th day of vaccination.

A total of 664,722 patients were included in the sample. The patients had a median age of 51 years and were predominantly women (56.9%). Overall, the incidence rate for COVID-19 breakthrough infection was 5.0 per 1000 person-months among fully vaccinated persons but was higher after the Delta variant became the dominant SARS-CoV-2 strain. The incidence rate before June 20, 2021, when Delta become the dominant US variant, was 2.2 (95% CI, 2.2 to 2.2) per 1,000 person-months, compared with 7.3 (95% CI, 7.3 to 7.4) after. The study authors note that the observed breakthrough infection rate is higher than reported by Centers for Disease Control and Prevention surveillance data.

Compared with partial vaccination, full vaccination was associated with a 28% reduced risk for breakthrough infection (adjusted incidence rate ratio [AIRR], 0.72; 95% CI, 0.68 to 0.76). People with a breakthrough infection after full vaccination were more likely to be older and women. People with HIV infection (AIRR, 1.33; 95% CI, 1.18 to 1.49), rheumatoid arthritis (AIRR, 1.20; 95% CI, 1.09 to 1.32), and solid organ transplant (AIRR, 2.16; 95% CI, 1.96 to 2.38) had a higher rate of breakthrough infection, as well as higher levels of severe outcomes.

"The findings of this study suggest that nuanced guidance for COVID-19 prevention and control is needed for patients with immune dysfunction," the authors write. "Clinicians and patients should consider continuing nonpharmaceutical interventions even after vaccination, including mask wearing, social distancing, and avoiding densely crowded settings (especially indoors) as much as possible."
Dec 28 JAMA Intern Med study

 

Researchers find antibodies that neutralize Omicron and other variants

An international research team has identified four antibody classes that can neutralize not only the Omicron variant, but also other variants and related coronaviruses. They detailed their findings in a Dec 23 Nature study, which also shed more light on how Omicron mutations affect binding to human cells and may impact protection from earlier infection, vaccination, and treatments.

The team used pseudoviruses to explore how Omicron's spike protein, and that of other variants, binds to and enters human and animal cells using the angiotensin converting enzyme-2 (ACE2) receptor. Research team members are from the University of Washington and Humabs Biomed and Vir Biotechnology in Switzerland.

They found that Omicron's spike protein binds 2.4 times better than that of the original SARS-CoV-2 virus and that it can bind efficiently to mouse ACE2 receptors, suggesting that Omicron may be able to pass back and forth between animals and people.

Using antibody panels from people infected from earlier virus versions, plus those who were vaccinated or infected then vaccinated, they found that the six most commonly used vaccines had reduced ability to block infection, with little or no protection from Sputnik V, Sinopharm, or a single dose of Johnson & Johnson. They also found mRNA booster benefits for dialysis patients and that antibody treatments, except for sotrovimab, had no or reduced activity against Omicron.

When they compared larger panels of antibodies generated against earlier SARS-CoV-2 viruses, they found four classes that could still neutralize Omicron, as well as related coronaviruses (sarbecoviruses). They target one of four conserved areas of the spike protein, which could be used to design vaccines and treatments across a broad spectrum of variants.
Dec 23 Nature study
Dec 27 University of Washington
press release

 

Study finds racial disparities in antibiotic treatment for skin infections

Researchers studying antibiotic treatment for skin and soft tissue infections (SSTIs) found a potential racial disparity in antibiotic choice, according to a study published last week in JAMA Network Open.

Using multisite, cross-sectional data on hospitalized patients treated for SSTIs at 91 acute care hospitals, the researchers looked at antibiotic use by race. Little is known about racial disparities in SSTI treatment, but because racial differences in treatment for several medical conditions exist, the researchers hypothesized that there would be racial difference in the management of SSTIs.

Of the 1,242 patients treated for SSTIs from October 2018 to January 2019, 494 (45%) were female, 224 (18%) were Black, and 854 (69%) were White. The mean age was 58 years. History of penicillin allergy was more frequent in Black inpatients than White inpatients (23% versus 18%). Cefazolin, the first-line therapy for SSTIs caused by Staphylococcus aureus and Streptococcus species, was more commonly used in White inpatients than in Black inpatients (13% vs 5%), while clindamycin, an alternative treatment, was more frequently used in Black inpatients than White (12% vs 7%).

Adjusting for multiple factors, including methicillin-resistant S aureus (MRSA) infection and penicillin allergy, White inpatients were nearly three times as likely to be treated with cefazolin (adjusted odds ratio [aOR], 2.82; 95% confidence interval [CI], 1.41 to 5.63) and almost half as likely to be treated with clindamycin (aOR, 0.54; 95% CI, 0.30 to 0.96).

The study authors note that clindamycin is not recommended given frequent dosing and high potential for adverse effects, including Clostridioides difficile infection.

"Future work should evaluate the determinants of this observed difference and devise interventions to achieve pharmacoequity," they concluded.
Dec 23 JAMA Netw Open research letter

 

Ohio reports first Powassan virus case

Health officials in Ohio recently announced the state's first known Powassan virus case, which involves a resident near Lisbon who was hospitalized in October.

The location is Columbiana County in the eastern part of Ohio. The Columbiana Health District said in a Dec 23 statement that the patient had been admitted to Akron Children's Hospital with a suspected Powassan virus infection and is still hospitalized. Ohio's health department and its partners confirmed the rare infection, and lab tests at the US Centers for Disease Control and Prevention (CDC) have also confirmed the findings.

In the weeks ahead, the Ohio Health Department's zoonotic disease division will conduct surveillance in Columbiana County to see if ticks are carrying the virus.

Over the past decade, the CDC typically receives about 25 reports a year of Powassan virus disease, with reports increasing in recent years. Most illnesses have been reported from northeastern and Great Lakes regions. Symptoms range from headache to fever to encephalitis. There is no treatment.
Dec 23 Columbiana County Health District statement

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