April 3, 2025

RSV

Early Impact of RSV Vaccination in Older Adults in England
In England, the UK Joint Committee on Vaccination and Immunization advised an initial program for those turning 75 years old, with a catch-up to age 79 years, pending further data on protection of those who are older. On Sept 1, 2024, vaccination of individuals aged 75–79 years began in England using bivalent prefusion F (pre-F) vaccine (Abrysvo, Pfizer, New York, NY, USA). Researchers conducted an early assessment of the RSV vaccine program's impact on RSV-related hospitalizations in older adults. Results showed a discontinuity in hospitalization rates corresponding to a 30% reduction (95% CI 18–40, p<0·0001) in those aged 75–79 years and eligible for RSV vaccine.

COVID: Active Vaccination/Immunity

Evaluating the Effectiveness of 2024-2025 Seasonal mRNA-1273 Vaccination Against COVID-19-Associated Hospitalizations and Medically Attended COVID-19 among adults aged ≥18 years in the United States
This study evaluated the effectiveness of Moderna's updated mRNA–1273 vaccine targeting the KP.2 variant, compared to people who did not receive any 2024–2025 COVID–19 vaccine, in preventing COVID–19–associated hospitalizations and medically attended COVID–19 among adults aged ≥ 18 years in the United States during the 2024–2025 season. Data were extracted from linked administrative healthcare claims and electronic health records (EHR) for vaccinations from 23 August 2024 through 24 December 2024 and followed through 31 December 2024. They conducted a retrospective matched cohort study with propensity score weighting to adjust for differences between groups to assess vaccine effectiveness (VE) against COVID–19 outcomes. Overall, 465,073 mRNA-1273 KP.2 vaccine recipients were matched 1:1 to unexposed adults. The mean age was 63 years, with more than half of the population being 65 years or older. Approximately 70% of individuals had an underlying medical condition making them high risk for severe outcomes for COVID–19. VE was 52.8% against COVID–19–related hospitalization and 39.4% against medically attended COVID–19 over a median follow–up of 57 days. The mRNA–1273 KP.2 vaccine demonstrated significant incremental effectiveness in preventing hospitalization with COVID–19 and medically attended COVID–19 in adults during the 2024–2025 season to date. These findings support ongoing vaccination efforts to mitigate the public health impact of COVID–19.

COVID: Early Viral Phase

Metformin Alleviates Inflammatory Response and Severity Rate of COVID-19 Infection in Elderly Individuals
Between 1 March and 2 July 2022, a total of 649,657 cases of COVID-19 infection were reported in Shanghai, most of which were infected with Omicron BA.2.2 Variants. Of these, 413 were diabetic and were used in this study to analyze the putative link between metformin treatment and the severity of COVID-19 infection. These 413 patients had type 2 diabetes. These results are from a retrospective cohort study that included 5,217 patients aged between 18 and 102 years who were admitted to the North Campus of Ruijin Hospital, affiliated with Shanghai Jiao Tong University School of Medicine, from March 20, 2022, to June 18, 2022. They analyzed whether there was a difference in a number of parameters in type 2 diabetics receiving metformin therapy prior to infection compared to those not being treated with metformin therapy for the three months prior to getting COVID-19. They looked at risk of ICU admission, development of pneumonia, and length of hospital stay. This study also examined the correlation between metformin treatment and levels of IL-6, CRP, serum ferritin (SF), lymphocyte, CD4 at admission, as well as the increase in open reading frame 1ab gene cycle threshold (ORF1abCT) after one week of hospitalization. There were no differences in age, sex, BMI, comorbidities, number of vaccine doses or eGFR between patients receiving and not receiving metformin therapy. Compared with patients receiving no treatment, those receiving metformin had a shorter hospital stay (12.1 ± 5.9 days vs. 14.5 ± 8.2 days, p = 0.001). In the patients ≥ 60 years old, those receiving treatment had significantly lower levels of IL-6 (median, 12.3 pg/ml vs. 4.0 pg/ml, p = 0.026) and significantly higher levels of lymphocyte (median, 1.2 × 109/L vs. 1.4 × 109/L, p = 0.015) compared with those not receiving treatment. However, for the patients under 60, there were no significant differences observed in IL-6 and lymphocyte levels between those receiving treatment and those not. Patients under 60 years of age did not show a significant benefit from metformin.

COVID: The Late Phase/PASC/Long COVID

Reinfection with SARS-CoV-2 in the Omicron Era is Associated with Increased Risk of Post-Acute Sequelae of SARS-CoV-2 Infection: A RECOVER-EHR Cohort Study
These are results from a retrospective cohort study using data from the RECOVER consortium comprising 40 children’s hospitals and health institutions in the U.S. between January 2022 and October 2023. A total of 465,717 individuals under 21 years old (mean [SD] age 8.17 [6.58] years; 52% male) were included. Compared to the first infection, a second infection was associated with significantly increased risk of an overall PASC diagnosis (RR, 2.08; 95% confidence interval [CI], 1.68-2.59), and with many specific conditions including: myocarditis (RR, 3.60; 95% CI, 1.46-8.86); changes in taste and smell (RR, 2.83; 95% CI, 1.41-5.67); thrombophlebitis and thromboembolism (RR, 2.28; 95% CI, 1.71-3.04); heart disease (RR, 1.96; 95% CI, 1.69 to 2.28); acute kidney injury (RR, 1.90; 95% CI, 1.38 to 2.61); fluid and electrolyte (RR, 1.89; 95% CI, 1.62 to 2.20); generalized pain (RR, 1.70; 95% CI, 1.48 to 1.95); arrhythmias (RR, 1.59; 95% CI, 1.45-1.74); abnormal liver enzyme (RR, 1.56; 95% CI, 1.24 to 1.96); fatigue and malaise (RR, 1.50; 95% CI, 1.38 to 1.64); musculoskeletal pain (RR, 1.45; 95% CI, 1.37 to 1.54); abdominal pain (RR, 1.42; 95% CI, 1.34 to 1.50); postural orthostatic tachycardia syndromes (POTS)/dysautonomia (RR, 1.35; 95% CI, 1.20 to 1.51); cognitive functions (RR, 1.32; 95% CI, 1.15 to 1.50); and respiratory signs and symptoms (RR, 1.29; 95% CI, 1.25 to 1.33). The risks were consistent across various organ systems, including cardiovascular, respiratory, gastrointestinal, neurological, and musculoskeletal systems.