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Risk of Myocarditis or Pericarditis With High-Dose vs Standard-Dose Influenza Vaccine A Prespecified Secondary Analysis of the Randomized DANFLU-2 Trial.
Influenza is a known risk factor for developing myocarditis or pericarditis, and this large Danish study looked at the prevalence of the inflammatory condition across three flu seasons, from 2022 to 2025. 332,438 participants were randomized, and baseline characteristics were balanced across HD-IIV and SD-IIV groups. The incidence of myocarditis or pericarditis was lower among participants randomized to HD-IIV vs SD-IIV (19 vs 35 events; relative vaccine effectiveness, 45.71%P = .04) Results were consistent when events occurring before 14 days were included. No interactions were detected.
High-Dose vs Standard-Dose Influenza Vaccine and Cardiovascular Outcomes in Older Adults A Prespecified Secondary Analysis of the DANFLU-2 Randomized Clinical Trial
In is prespecified secondary analysis of the DANFLU-2 randomized clinical trial including 332,438 adults 65 years or older individually randomized to HD-IIV (high dose) or SD-IIV (standard dose), the incidence of cardiorespiratory hospitalization was 2.25% in the HD-IIV group and 2.38% in the SD-IIV group. The difference was driven primarily by a lower incidence of cardiovascular hospitalization (1.30% vs 1.40%).
Influenza Vaccination to Improve Outcomes for Patients with Acute Heart Failure (PANDA II): A Multiregional, Seasonal, Hospital-based, Cluster-randomised, Controlled Trial in China
Investigators undertook a pragmatic, multiregional, parallel-group, cluster (hospital)-randomised, controlled, superiority trial over three winter seasons in China. Overall, 7,771 participants were enrolled at 164 hospitals in each winter season between Dec 3, 2021, and Feb 14, 2024, with 3,570 assigned to the influenza vaccination group and 4201 to the usual care (control) group. The primary outcome was a composite of all-cause mortality or any hospital readmission over 12 months. The primary outcome occurred in 1,378 (41·2%) of 3342 patients in the vaccination group and in 1,843 (47·0%) of 3,919 patients in the usual care group (odds ratio 0·83 [95% CI 0·72–0·97]; p=0·019). The result was consistent in the sensitivity analysis. The number of participants with a serious adverse event was significantly lower in the vaccination group (1809 [52·5%] of 3444) than the usual care group (2426 [59·0%] of 4110; odds ratio 0·82 [0·70–0·96]; p=0·013).
SARS-CoV-2 Vaccine-Elicited Antibody Responses in Human Milk
Authors enrolled 13 participants prior to receiving SARS-CoV-2 immunization. They measured anti-SARS-CoV-2 Spike IgG or IgA in serum and self-collected breast milk in participants over a 6-month period. Breast milk was processed by removing lipids and cellular debris by cold centrifugation, and skim milk was then filtered for binding antibody multiplexed assays and neutralization assays. They found that postpartum immunization with a SARS-CoV-2 mRNA-LNP vaccine elicits a robust IgG response and moderate IgA response in serum, which is transferred to breast milk. Serum was able to neutralize pseudovirus after completion of the vaccine schedule. These responses persisted for several months predominantly in persons with a potential history of SARS-CoV-2 infection.
Interferon-α Nasal Spray Prophylaxis Reduces COVID-19 in Cancer Patients: A Randomized, Double-Blinded, Placebo-Controlled Trial
Participants were randomized 1:1 to receive daily 40,000 IU IFN-α nasal spray or normal saline placebo. Participants who developed influenza-like symptoms self-collected nasal swabs for PCR testing of SARS-CoV-2, influenza A/B, respiratory syncytial virus, parainfluenza, adenovirus, seasonal coronavirus, picornavirus, human metapneumovirus, and/or SARS-CoV-2 rapid antigen testing. Co-primary endpoints were incidence of COVID-19 and/or other respiratory viruses ≤90 days of randomization. Four hundred and thirty-three participants were randomized to IFN-α (n = 217) or placebo (n = 216). The incidence of COVID-19 was lower in the IFN-α group versus placebo (8.3% vs 14.4%), indicating a 40% reduced risk of infection (relative risk [RR]: .60; 95% credible interval [CrI]: .33–.97). Other respiratory viral infection incidence was 5.1% and 5.1% in both groups (RR: 1.12; .43–2.34). In the per-protocol cohort (n = 389), the incidence of COVID-19 in IFN-α and placebo groups was 7.7% and 16.0% (RR: .50; .26–.84) with other respiratory virus incidence of 4.6% and 5.7%, respectively. Subgroup analysis demonstrated lower COVID-19 in the IFN-α group for ages <65 years (RR: .48; .20–.92), female sex (RR: .44; .19–.85), and COVID-19 vaccinated (RR: .50; .26–.82), but no difference by underlying malignancy. No differences were observed in secondary endpoints of severity, hospitalization, and mortality. IFN-α was well tolerated and safe.
Azelastine Nasal Spray for Prevention of SARS-CoV-2 Infections A Phase 2 Randomized Clinical Trial
These are the results of a A phase 2, double-blind, placebo-controlled, single-center trial conducted from March 2023 to July 2024. Healthy adults from the general population were enrolled at the Saarland University Hospital in Germany. Participants were randomly assigned 1:1 to receive azelastine, 0.1%, nasal spray or placebo three times daily for 56 days. SARS-CoV-2 rapid antigen testing (RAT) was conducted twice weekly, with positive results confirmed by polymerase chain reaction (PCR). Symptomatic participants with negative RAT results underwent multiplex PCR testing for respiratory viruses. The primary end point was the number of PCR-confirmed SARS-CoV-2 infections during the study. A total of 450 participants were randomized, with 227 assigned to azelastine and 223 to placebo. In the intention-to-treat (ITT) population, the incidence of PCR-confirmed SARS-CoV-2 infection was significantly lower in the azelastine group (n = 5 [2.2%]) compared with the placebo group (n = 15 [6.7%]) (OR, 0.31; 95% CI, 0.11-0.87). As secondary end points, azelastine demonstrated an increase in mean (SD) time to SARS-CoV-2 infection among infected participants (31.2 [9.3] vs 19.5 [14.8] days), a reduction of the overall number of PCR-confirmed symptomatic infections (21 of 227 participants vs 49 of 223 participants), and a lower incidence of PCR-confirmed rhinovirus infections (1.8% vs 6.3%). Adverse events were comparable between the groups.
Effect of Metformin on the Risk of Post-coronavirus Disease 2019 Condition Among Individuals with Overweight or Obese: A Population-based Retrospective Cohort Study
Authors used the Clinical Practice Research Datalink (CPRD) Aurum, a UK primary care database representing the population in England. The study used a target trial emulation framework to compare the effect of metformin versus no metformin on developing PCC in individuals with overweight or obesity after SARS-CoV-2 infection. Subgroup analyses were conducted on a subset of individuals based on age, BMI, gender, diabetes status, and the dominant SARS-CoV-2 variant at the time of COVID-19 diagnosis. A total of 766,859 overweight or obese patients with a record of SARs-CoV-2 infection were identified from the database during the study period. Of these, 624,308 patients met the eligibility criteria and were included in the analysis. There were 2,976 patient-initiated metformin within three months after COVID-19 diagnosis date in this study. The one-year risk difference for PCC in the intention-to-treat analysis was −12.58% (hazard ratio 0.36; 95% CI, 0.32–0.41), with consistent results in subgroup analyses. Study found that individuals with overweight or obesity who initiated metformin within three months after a COVID-19 diagnosis had a lower one-year risk of developing PCC compared to those who did not initiate metformin.
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