We analyzed the antibody responses of 564 hospital workers in Athens, Greece, after vaccination with two doses of the BNT162b2 (Comirnaty^®; BioNTech and Pfizer) mRNA COVID-19 vaccine. A greater antibody increase was observed in women, younger age groups, previously infected individuals and personnel working in COVID-19 clinics. Notably, individuals with a prior COVID-19 infection mounted a significantly higher antibody titer following the first dose than the rest of the population; the same was true for those working in COVID-19 clinics, even without history of previous infection.

Mechanisms of ischemic stroke in young adults are poorly understood. The aim of the study was to investigate and compare the frequency of common variations in prothrombotic genes between young patients with ischemic stroke and controls. Fifty-one cases of first-ever ischemic stroke and 70 community-based controls aged below 50 years were studied. In both groups, the insertion/deletion 4G/5G variation (−675 4G/5G PAI-1) as well as the single-nucleotide polymorphism-844 G/A of the PAI-1 (−844 G/A PAI-1) gene promoter, factor V Leiden (FVL) G1691Α, the prothrombin variant (allele 20210A, FIIG20210A), factor XIII-A Val34Leu polymorphism (FXIII-AVal34Leu) and C677T methylenotetrahydrofolate reductase (C677T MTHFR) polymorphism have been assessed. The −675 4G/5G PAI-1 allele distribution differed significantly between patients and controls (P = 0.020), but no difference was found regarding the distribution of −844 G/A PAI-1 (P = 0.493), FVL (P = 0.199), FIIG20210A (P = 0.410), FXIII-AVal34leu (P = 0.160) and C677T MTHFR (P = 0.788). A lower frequency of 5G/5G genotype and a higher frequency of the 4G/5G genotype of the PAI −675 4G/5G polymorphism was found in young ischemic stroke patients compared to healthy controls. Further epidemiological studies are needed to investigate the differences between different geographic areas, and prospective cohort studies are needed to investigate the possible protective role of 5G/5G polymorphism.

Seasonal influenza remains a major global public health challenge despite decades of vaccine development, underscoring the need for more effective and adaptable immunization strategies. The recently approved mRNA-1010 vaccine represents a promising advance by applying messenger RNA technology to a pathogen characterized by continuous antigenic drift. Recent Phase 3 clinical trials conducted in support of regulatory review have demonstrated robust immunogenicity and superior protective efficacy against seasonal influenza compared with standard influenza vaccines in adults aged 50 years and older. However, increased reactogenicity, particularly among younger adults, together with the need for continued post-marketing safety surveillance, highlights the balance between enhanced immune responses and tolerability. Beyond seasonal influenza, mRNA-1010 provides a foundation for next-generation respiratory vaccines, including combination formulations targeting influenza, SARS-CoV-2, and respiratory syncytial virus (RSV), while illustrating the broader potential of mRNA vaccine technology. At the same time, challenges related to manufacturing scalability, cost, cold-chain requirements, and global accessibility remain important considerations for widespread implementation. This perspective examines whether mRNA-1010 represents an incremental advance in influenza vaccination or a potential transformative milestone in respiratory immunization, while considering the continuing roles of alternative vaccine platforms in achieving optimal effectiveness, safety, and equitable global access.

Seasonal influenza and the ongoing emergence of zoonotic influenza viruses, including highly pathogenic avian influenza A (H5N1), remain substantial global public health threats, underscoring the need for rapidly adaptable vaccine platforms. This state-of-the-art review critically evaluates the clinical development of RNA-based influenza vaccines through a comprehensive assessment of ClinicalTrials.gov records and peer-reviewed literature. Candidates were examined across four domains: seasonal influenza vaccines, pre-pandemic influenza vaccines, combination respiratory vaccines, and self-amplifying RNA (saRNA) platforms. Clinical evidence indicates that mRNA influenza vaccines consistently elicit robust humoral immune responses and, in late-stage trials, have demonstrated improved relative efficacy against influenza A compared with conventional influenza vaccines. Reactogenicity is generally more frequent with mRNA vaccines, particularly with respect to transient mild-to-moderate systemic adverse events. However, serious adverse events remain uncommon and broadly comparable to those observed with licensed comparator vaccines. Pre-pandemic and multicomponent mRNA vaccine candidates similarly demonstrate strong immunogenicity, supporting the potential of RNA platforms for both seasonal vaccination and pandemic preparedness. Clinical development of saRNA influenza vaccines has progressed through early-phase trials, although publicly available clinical data remain limited. Regulatory milestones in 2026, including U.S. approval of mRNA-1010 (mFlusiva), the first approved mRNA-based seasonal influenza vaccine, and European Union authorization of mRNA-1083 (mCOMBRIAX), an mRNA-based influenza-COVID-19 combination vaccine, represent important steps in the clinical transition and implementation of RNA-based influenza vaccination.