influenza vaccine (Ultravac / Ultravak)

Genomic evolution patterns of influenza A/H1N1 in Iraqi patients revealed by nanopore sequencing.

Owaid Farah M FM, Fadhil Hula Y HY

Influenza viruses have high mutation rates and cause serious health problems worldwide. In our population, no study has examined mutations and their variation relative to the wild-type and vaccine strains. Study focused on whole-genome sequencing to characterize the virus, construct phylogenetic trees, analyze mutations, and assess nucleotide diversity. Nasal swabs were collected from 170 patients with RTI (SARI or ILI) in Baghdad and Wasit from November 2024 to March 2025, and tested for influenza A virus detection and typing by real-time reverse transcription polymerase chain reaction. The 14 positive viral genomes were sequenced using the MinION nanopore platform. 49 influenza viral genomes were identified as positive cases, comprising 48 A/H1N1 and 1 A/H3N2 strain. Nine complete A/H1N1 were sequenced, revealing nonsynonymous mutations, especially in the hemagglutinin (HA), neuraminidase (NA), and nonstructural protein 1 (NS1) genes. Nucleotide diversity analysis revealed negative selection in certain A/H1N1 genes. Mutations were detected in antigenic and functional regions of HA and NA, indicating ongoing antigenic drift in circulating strains. Phylogenetic analysis showed that the Iraqi isolates were closely related to contemporary regional and global strains reported from neighboring countries such as Iran and Saudi Arabia, and were partially genetically related to recent vaccine strains such as A/Wisconsin/67/2022 and A/Missouri/11/2025. By contrast, the older vaccine strains suggest that Iraqi influenza viruses are evolving slowly, accumulating mutations continuously, while the important internal proteins are conserved. Mutations across all eight genome segments will be crucial for elucidating the genetic evolution of influenza A viruses in Iraq.

The Dual Role of Preexisting Immunity in Influenza: Protective Recall Versus Constraint of Novel Responses.

Fox Annette A, Zhu Ziheng Z, Sánchez-Ovando Stephany S

Preexisting immunity to influenza confers rapid protection against antigenically matched viruses but can also constrain responses to drifted variants. This review asks when and why prior infection or vaccination is protective versus detrimental, and which biological mechanisms-epitope masking by circulating antibody, inhibitory FcγRIIb signaling, and competitive dominance by affinity-matured memory B cells-drive these outcomes. We synthesize human cohort, serological, and vaccine-effectiveness data with mechanistic mouse and fate-mapping studies to explore how vaccine formulation, antigen dose, antigenic distance and T cell help modulate the balance between memory recall and recruitment of naïve B cells. Finally, we outline strategies (higher dose, adjuvants, multivalent display, and considered strain selection) to restore de novo responses against escape epitopes and improve vaccine performance.

Herpes zoster recurrence in primary care: Unmeasured residual confounding, the recombinant vaccine era, and external validity for Latin America.

Therán-León Juan Sebastián JS, Hernández-Cañas María Camila MC, Quintero-Arévalo Bárbara Yuliana BY

Defining the Efficacy of Meningococcal B Vaccines Against Gonococcal Acquisition: The Current Landscape.

Seib Kate L KL, Grulich Andrew E AE

Gonorrhoea is a major global sexually transmitted infection, with rising incidence and increasing antimicrobial resistance threatening current control strategies. If untreated, Neisseria gonorrhoeae can lead to severe reproductive health sequelae. Gonorrhoea is also linked to increased HIV acquisition and transmission. There is currently no vaccine licensed to prevent gonorrhoea. However, observational evidence suggests that outer membrane vesicle-based serogroup B meningococcal vaccines, including the four-component meningococcal B (4CMenB) vaccine, confer partial cross-protection against gonorrhoea. We discuss observational studies and randomized controlled trials (RCTs) focused on defining the efficacy of 4CMenB against gonorrhoea. Observational studies from multiple settings have reported an association between receipt of 4CMenB vaccine and reduced gonorrhoea risk, with a meta-analysis estimating a 38% reduction in risk. Neisseria meningitidis and N. gonorrhoeae are closely related bacteria that share numerous antigens, making cross-protection biologically plausible. Based on observational data, 4CMenB immunization programmes have been implemented in two countries with the aim of preventing gonorrhoea. However, three RCTs have recently shown that 4CMenB is not effective in preventing gonorrhoea in gay, bisexual and other men at high risk of acquisition. Several RCTs are ongoing, looking at efficacy in different populations, including women and people at lower risk of acquisition. The different outcomes between the observational studies and RCTs may be due to a range of known and unknown confounding factors, and differences in the populations considered in the different studies. Current evidence from RCTs does not support the use of 4CMenB to prevent gonorrhoea in gay and bisexual men at high risk of acquisition. Results from ongoing RCTs will be critical to determine whether vaccine efficacy varies by population or epidemiological context and to inform future gonorrhoea vaccine policy and development.