October 30, 2025

SARS-CoV-2 mRNA Vaccination: Cancer Benefit

SARS-CoV-2 mRNA Vaccines Sensitize Tumors to Immune Checkpoint Blockade
Immune checkpoint inhibitors (ICIs) extend survival in many patients with cancer but are ineffective inpatients without pre-existing immunity. Here authors show that mRNA vaccines targeting SARS-CoV-2also sensitize tumours to ICIs. In preclinical models, SARS-CoV-2 mRNA vaccines led to a substantial increase in type I interferon, enabling innate immune cells to prime CD8+T cells that target tumour-associated antigens. Concomitant ICI treatment is required for maximal efficacy in immunologically cold tumours, which respond by increasing PD-L1 expression.Similar correlates of vaccination response are found in humans, including increases in type I interferon, myeloid–lymphoid activation in healthy volunteers and PD-L1 expression on tumours. Moreover, receipt of SARS-CoV-2 mRNA vaccines within 100 days of initiating ICI is associated with significantly improved median and three-year overall survival in multiple large retrospective cohorts. This benefit is similar among patients with immunologically cold tumours.

Viral Infection and Cardiovascular Disease

Viral Infections and Risk of Cardiovascular Disease: Systematic Review and Meta-Analysis
Investigators conducted a systematic review and meta-analysis of studies examining the association of viral infections with the risk of cardiovascular disease, including coronary heart disease (CHD) and stroke. SARS-CoV-2 infection (so COVID-19) was associated with an increased risk of coronary heart disease (CHD) (RR, 1.74) and stroke (RR, 1.69). Laboratory-confirmed influenza infection was associated with an elevated risk of acute myocardial infarction (pooled incidence rate ratio, 4.01) and stroke during the first 1 month (incidence rate ratio, 5.01 [95% CI,3.41–7.37]). Herpes zoster was also associated with a minimally elevated risk of CHD (RR, 1.12) and stroke (RR, 1.18). They also found increased risks associated with Hepatitis and HIV.

RSV: Revaccination

Safety, Tolerability, and Immunogenicity of Revaccination With mRNA-1345, an mRNA Vaccine Against RSV, Administered 12 Months Following a Primary Dose in Adults Aged ≥ 50 Years
This open-label, phase 3 trial evaluated revaccination with 50μg mRNA-1345 administered 12 month safer primary vaccination in participants aged ≥ 50 years. The primary objectives were the immunogenicity (RSV-A and RSV-B neutralizing antibody [nAb] responses), tolerability, and safety of revaccination. Overall, 543 participants were revaccinated. Most adverse reactions were mild/moderate (median duration, 2 days), with no new safety concerns identified. Coprimary immunogenicity endpoints met pre-specified non inferiority criteria based on Day 29 geometric mean titer ratios(GMRs; revaccination vs primary vaccination). At Day 29, nAb GMRs (95% confidence interval [CI]) were 1.08 (1.0–1.17) for RSV-A and 0.91 (.84–.98) for RSV-B. Seroresponse rates(≥4-fold rise from baseline; 95% CI) at Day 29 were 77.5% (73.7–81.0) for RSV-A and 47.5% (43.2–51.9) for RSV-B, with a ≥2-fold rise in titers observed in 91.6% (88.9–93.8) and 69.8% (65.7–73.8) of participants, respectively. Following primary vaccination, RSV nAb titers increased by Day 29 and gradually declined over 12 months, yet remained above baseline levels. Revaccination at 12 months increased nAb titers, similar to the response observed after the primary dose.

COVID: Active Vaccination/Immunity

Association of 2024–2025 Covid-19 Vaccine with Covid-19 Outcomes in U.S. Veterans
This is an observational study that used the electronic health records of the Department of Veterans Affairs to evaluate the effectiveness of the 2024–2025 Covid-19 vaccine among veterans who received the Covid-19 and influenza vaccines on the same day (164,132 participants) and in an active-comparator group of veterans who received the influenza vaccine only (131,839 participants), between September 3 and December 31, 2024. Participants were followed for 180 days or until the occurrence of an outcome, whichever came first. At 6 months of follow-up, the estimated vaccine effectiveness was 29.3% against Covid-19–associated emergency department visits, 39.2% against Covid-19–associated hospitalizations, 64.0% against Covid–19–associated deaths. Durability of 2024-2025 COVID-19 Vaccines Against JN.1 Subvariants.

Durability of 2024-2025 COVID-19 Vaccines Against JN.1 Subvariants
On August 22, 2024, the US Food and Drug Administration authorized for emergency use the updated 2024-2025 messenger RNA COVID-19 vaccines targeting the KP.2 strain of the JN.1 variant for persons 6 months or older. On August 30, 2024, the Food and Drug Administration also granted emergency use authorization for an updated Novavax COVID-19 vaccine containing the spike protein of the JN.1 variant for persons 12 years or older. Here they collected individual-level data on the uptake of the updated 2024-2025 COVID-19 vaccines and the incidence of COVID-19 between August 22, 2024, and April 16, 2025, for a cohort of approximately 1.8 million persons. They evaluated 3 clinical outcomes: SARS-CoV-2 infection, COVID-19–related emergency department visit, and COVID–19–related hospitalization or death. Of 237,203 individuals, 86,594, 148,429, and 2,180 received the updated Moderna, Pfizer-BioNTech, and Novavax vaccines, respectively. Vaccine effectiveness against infection reached a level of 44.7% (95% CI, 37.7%-50.9%) at 4 weeks post vaccination, declined to 35.5% (95% CI, 30.2%-40.5%) at 10 weeks, and further decreased to 16.7% (95% CI, 8.4%-24.2%) by 20 weeks, Effectiveness against emergency department visit reached 45.1% (95% CI, 28.9%-57.6%) at 4 weeks, declined slightly to 42.9% (95% CI, 32.5%-51.7%) at 10 weeks, and remained at 39.1% (95% CI, 13.4%-57.2%) at 20 weeks. For hospitalization or death, effectiveness reached 57.3% (95% CI, 42.6%-68.1%) at 4 weeks, declined to 49.7% (95% CI, 39.2%-58.4%) at 10 weeks, and dropped to 34.0% (95% CI, 7.0%-53.1%) at 20 weeks.