Respiratory Diseases Roundup

N95 vs. Medical Masks, Long COVID Risks, and More

Miranda Manier, BA

N95 Respirators vs. Medical Masks for COVID-19 Protection in Health Care Workers1

A recent multicenter randomized trial examined whether medical masks provide similar protection against COVID-19 compared with N95 respirators among health care workers. Conducted across 29 facilities in Canada, Israel, Pakistan, and Egypt, the study followed 1009 health care workers providing direct care to patients with COVID-19. The results showed no statistically significant difference in COVID-19 infection rates between those wearing medical masks (10.46%) and those using N95 respirators (9.27%), with a hazard ratio of 1.14 (95% CI, 0.77–1.69). However, country-specific variations suggested differing risks, with Canada showing a higher infection rate among medical mask users.

The study acknowledged several limitations, including potential non-workplace exposure, differences in circulating variants, and varying levels of vaccine coverage. While adverse events were slightly higher among N95 respirator users (13.6% vs. 10.8% in the medical mask group), researchers concluded that overall, medical masks did not significantly increase infection risk in routine care settings. The findings highlight the role of broader public health measures and individual risk factors in COVID-19 transmission.

COVID-19 and Influenza Hospitalization and Mortality Burden2

An observational cohort study in Denmark compared the burden of COVID-19 and influenza from May 2022 to June 2024. Among nearly 5.9 million residents, COVID-19 hospitalizations (24,400 cases) were more than double those of influenza (8385 cases), with an adjusted incidence rate ratio (aIRR) of 2.04 (95% CI, 1.38–3.02). COVID-19 also resulted in significantly higher mortality, with 2361 deaths versus 489 from influenza (aIRR = 3.19; 95% CI, 2.24–4.53). The risk of death was particularly elevated among unvaccinated individuals, those with comorbidities, and men.

Despite a general decline in COVID-19 cases since 2022, the study highlights that SARS-CoV-2 continues to impose a greater burden than influenza, particularly in older adults and during non-winter months. These findings emphasize the importance of continued vaccination efforts and public health measures to mitigate COVID-19’s impact, especially among vulnerable populations.

Study: Inflammatory Markers Predict Long COVID Severity in Postmenopausal Women3

A study investigating long COVID in postmenopausal women found that pre-pandemic inflammatory markers may predict disease severity. Using biomarker data from blood samples collected between 1993 and 1998, researchers analyzed 1237 participants from the Women’s Health Initiative who later completed a COVID-19 survey between 2021 and 2022. Higher leukocyte counts measured decades before the pandemic were associated with more severe long COVID symptoms (β = 0.27; 95% CI, 0.07–0.47, P = .009), although they were not linked to overall risk of developing long COVID or cognitive impairment.

While this study suggests that pre-existing inflammation plays a role in long COVID severity, the findings were limited by a smaller dataset for high-sensitivity C-reactive protein, another marker of inflammation. Researchers call for further studies to determine how long-term immune dysregulation may contribute to post-viral conditions and whether early interventions could mitigate future disease severity.

Rare Disease Patients May Face Higher COVID-19 Mortality Risks4

A large-scale analysis of 58 million electronic health records (EHRs) in England provided the first national prevalence estimates for 331 rare diseases and examined their impact during the COVID-19 pandemic. The study identified 894,396 individuals with at least one rare disease and found that their COVID-19 mortality rate (0.9%) was significantly higher than in the general population (0.2%). Even among fully vaccinated individuals, eight rare diseases were associated with increased mortality risk, with bullous pemphigoid patients facing the highest risk (HR = 8.07; 95% CI, 3.01–21.62).

By leveraging national-scale health data, researchers demonstrated the value of large EHR studies in identifying vulnerable populations. The findings highlight the urgent need for improved clinical guidelines and public health strategies tailored to patients with rare diseases, ensuring better protection in future pandemics.

References

  1. Loeb M, Bartholomew A, Hashmi M, et al. Medical masks versus N95 respirators for preventing COVID-19 among health care workers: a randomized trial. Ann Intern Med. 2022;175(12):1629-1638. doi:10.7326/M22-1966
  2. Bager P, Svalgaard IB, Lomholt FK, et al. The hospital and mortality burden of COVID-19 compared with influenza in Denmark: a national observational cohort study, 2022-24. Lancet Infect Dis. Published online January 29, 2025. doi:10.1016/S1473-3099(24)00806-5
  3. Ng TKS, Beydoun HA, Von Ah D, et al. Pre-pandemic leukocyte count is associated with severity of post-acute sequelae of SARS-CoV-2 infection among older women in the Women's Health Initiative. Menopause. Published online January 28, 2025. doi:10.1097/GME.0000000000002490
  4. Thygesen JH, Zhang H, Issa H, et al. Prevalence and demographics of 331 rare diseases and associated COVID-19-related mortality among 58 million individuals: a nationwide retrospective observational study. Lancet Digit Health. 2025;7(2):e145-e156. doi:10.1016/S2589-7500(24)00253-X