New Clues in COVID-19 Detection, Treatment, and Risk
Key Highlights:
- A wearable device detected SARS-CoV-2 infection up to 7 days earlier than symptom-based methods.
- Nirmatrelvir-ritonavir and remdesivir likely reduce hospitalization in mild or moderate COVID-19.
- RSV leads to higher hospitalization mortality and complications than influenza.
- Adult survivors of childhood cancer had a 58% higher risk of severe COVID-19 compared to peers.
Wearable Device Detects COVID-19 Earlier Than Symptoms
A randomized controlled trial of 17,825 participants assessed the utility of the Ava bracelet—a wearable device that measures physiological parameters—for early detection of SARS-CoV-2 infections. Participants were randomized to an experimental group receiving real-time alerts based on wearable and symptom data, or a control group relying on symptom reports alone. Those in the experimental group received alerts a median of 7 days earlier than those in the control group. The experimental algorithm demonstrated high sensitivity (93.8–99.2%) but low specificity (0.8–4.2%) during a defined detection window. In contrast, the control algorithm had moderate sensitivity (43.3–46.4%) and higher specificity (65.0–66.4%).
The algorithm used with the wearable also performed better in detecting infections on a given day, with a sensitivity of 45–52%, compared to 28–33% for the symptom-based method, though specificity was again lower (38–50% vs. 93–97%). The findings support the potential of wearable technology in the early detection of infectious diseases, though refinement is needed to reduce false positives and distinguish among types of respiratory illness.
Certain COVID-19 Medications Likely Reduce Hospitalization
A systematic review and network meta-analysis of 187 trials involving more than 166,000 patients with non-severe COVID-19 compared the effectiveness of various medication treatments and found with moderate certainty that nirmatrelvir-ritonavir and remdesivir likely reduce hospitalization rates when compared with standard care. Systemic corticosteroids and molnupiravir may also be beneficial, but with lower certainty. Azithromycin, corticosteroids, molnupiravir, favipiravir, and umifenovir likely reduce time to symptom resolution, according to the results of the systematic review and meta-analysis. Lopinavir-ritonavir was the only treatment associated with a higher rate of adverse effects leading to drug discontinuation.
Mortality, need for mechanical ventilation, and risks of venous thromboembolism or major bleeding did not differ convincingly across most treatments when compared with standard care. Overall, while some medications showed benefit in mild or moderate COVID-19, evidence for many treatments remains uncertain. These findings inform the WHO’s living guidelines on COVID-19 therapeutics and underscore the importance of stage-specific treatment strategies.
RSV Infections More Severe Than Influenza in Adults
A territory-wide retrospective cohort study from Hong Kong examined 41,206 influenza and 3565 RSV-related hospitalizations. RSV infection was associated with higher in-hospital mortality (10.1% vs. 5.5%), greater incidence of severe respiratory failure (22.7% vs. 13.3%), secondary bacterial pneumonia (61.5% vs. 39.5%), and acute kidney injury (16.0% vs. 12.6%) than influenza. These outcomes remained significant across age groups—including patients younger than 60 years of age—and were confirmed in propensity score–matched analyses.
End-stage kidney disease requiring renal replacement therapy emerged as a strong independent risk factor for mortality and complications among patients with RSV. The study supports reconsideration of current RSV vaccination guidelines, which often exclude individuals younger than 60 years old. Broader vaccination strategies may be warranted, particularly for patients with comorbid conditions such as kidney disease and cardiopulmonary disorders.
Childhood Cancer Survivors at Higher Risk for Severe COVID-19
In a Nordic register-based cohort study including 13,659 childhood cancer survivors and 76,000 comparators (general population and siblings), researchers observed a 58% increased risk of severe COVID-19 (adjusted hazard ratio [aHR] = 1.58; 95% CI = 1.25–1.98) among survivors. The results showed that survivors had a lower risk of registered COVID-19 infection (aHR = 0.91; 95% CI = 0.89–0.94), suggesting more cautious behavior or fewer exposures. The elevated risk was most pronounced during periods of high viral transmission, particularly during the Alpha and Omicron variant waves.
The heightened risk of severe outcomes persisted across both Denmark and Sweden despite different pandemic responses and was especially notable in survivors diagnosed at age 15 years or older or those aged 50 years or older at the start of the pandemic. These findings point to the need for targeted public health measures and vaccination prioritization for adult survivors of childhood cancer, especially during infectious disease outbreaks.
References:
- Zwiers LC, Brakenhoff TB, Goodale BM, et al. Remote early detection of SARS-CoV-2 infections using a wearable-based algorithm: Results from the COVID-RED study, a prospective randomised single-blinded crossover trial. PLoS One. 2025;20(6):e0325116. doi:10.1371/journal.pone.0325116
- Ibrahim S, Siemieniuk RAC, Oliveros MJ, Islam N, Díaz Martinez JP, Izcovich A, Qasim A, Zhao Y, Zaror C, Yao L, Wang Y, et al. Drug treatments for mild or moderate covid-19: systematic review and network meta-analysis. BMJ. 2025;389:e081165. doi:10.1136/bmj-2024-081165
- Louro J, Kampitsi CE, Mogenson H, et al. COVID-19 infection and severity among childhood cancer survivors in Denmark and Sweden: a register-based cohort study with matched population and sibling comparisons. Lancet Reg Health Eur. 2025;38:100846. doi:10.1016/j.lanepe.2025.101363
- Kwok WC, Leung ISH, Ho JCM, et al. In-hospital mortality and severe respiratory and renal outcomes-a territory-wide comparison between RSV and influenza. Influenza Other Respir Viruses. 2025;19(6):e70130. doi:10.1111/irv.70130