Safety profile of MenB-FHBp vaccine among adolescents: data from surveillance of Adverse Events Following Immunization in Puglia (Italy), 2018-2020

Adverse events following immunization (AEFIs) with anti-meningococcus type B vaccine (4CMenB): Data of post-marketing active surveillance program. Apulia Region (Italy), 2019-2023

The four-component recombinant-DNA anti-meningococcus B vaccine (4CMenB) has been approved by the European Medicines Agency in 2013. In Italy, 4CMenB is recommended since 2017 for use in infants under one year of age. Due to the strong evidence of increased risk of fever after administration, surveillance of adverse events following immunization (AEFIs) is a priority for 4CMenB. This cross-sectional prospective study aims at investigating 4CMenB's safety profile. The study population is represented by infants under twelve months of age vaccinated with 4CMenB in selected ambulatories in Apulia, a region in South-Eastern Italy, from October 1st, 2020, to March 31st, 2023. Parents were provided with a post-vaccination diary covering up to seven days after immunization and were contacted one week after the vaccination day. Information about AEFIs was collected, and reactions were classified following World Health Organization guidelines. For serious AEFIs, causality assessment was carried out. AEFI risk determinants were investigated via logistic regression. A total of 4,773 diaries were completed, with 78.13 % of them (3,729/4,773) containing one or more AEFI reports. Systemic reactions such as malaise, drowsiness/insomnia and fatigue were the most common ones, followed by fever and local pain, tenderness, redness and swelling. Twenty-three cases of serious AEFIs were reported. Following causality assessment, 78.26 % of serious adverse events (18/23) were deemed to have a consistent causal association with the administration of 4CMenB (reporting rate: 0.38 %). Three infants were hospitalized following vaccination, but no cases of death or permanent/severe impairment were reported. Prophylactic paracetamol administration showed a significant protective effect against the risk of manifesting fever within the first 24 h after administration (OR: 0.75; p < 0.005). Our data confirms existing evidence regarding the safety of 4CMenB vaccination in babies under 2 years of age, but also highlight a significant risk of fever after vaccination. Prophylactic paracetamol administration could represent a protective factor against fever, especially during the first 24 h after vaccination.

Meningococcal B Immunisation in Adults and Potential Broader Immunisation Strategies: A Narrative Review

Recombinant vaccines against invasive meningococcal disease due to Neisseria meningitidis serogroup B (MenB) have shown substantial impact in reducing MenB disease in targeted populations. 4CMenB targets four key N. meningitidis protein antigens; human factor H binding protein (fHbp), Neisserial heparin binding antigen (NHBA), Neisseria adhesin A (NadA) and the porin A protein (PorA P1.4), with one or more of these expressed by most pathogenic MenB strains, while MenB-FHbp targets two distinct fHbp variants. While many countries recommend MenB immunisation in adults considered at high risk due to underlying medical conditions or immunosuppression, there are no recommendations for routine use in the general adult population. We reviewed the burden of MenB in adults, where, while incidence rates remain low (and far lower than in young children < 5 years of age at greatest risk), a substantial proportion of MenB cases (20% or more) is now observed in the adult population; evident in Europe, Australia, and in the United States. We also reviewed immunogenicity data in adults from clinical studies conducted during MenB vaccine development and subsequent post-licensure studies. A 2-dose schedule of 4CMenB generates hSBA titres ≥ 1:4 towards all four key vaccine target antigens in up to 98-100% of subjects. For MenB-FHbp, a ≥ fourfold rise in hSBA titres against the four primary representative test strains was observed in 70-95% of recipients following a 3-dose schedule. While this suggests potential benefits for MenB immunisation if used in adult populations, data are limited (especially for adults > 50 years) and key aspects relating to duration of protection remain unclear. Although a broader adult MenB immunisation policy could provide greater protection of the adult population, additional data are required to support policy decision-making.

Invasive Meningococcal Disease and Meningococcal Serogroup B Vaccination in Adults and Their Offspring: Knowledge, Attitudes, and Practices in Italy (2019)

Despite its effectiveness in preventing invasive meningococcal disease (IMD), pediatric uptake of recombinant meningococcal vaccination for serogroup B meningitis (MenB) is low in Italy. This study aimed to investigate knowledge, attitudes, and practice (KAP) about IMD and the vaccine uptake for MenB from July to December 2019, in a sample collected from a series of local Facebook discussion groups from the provinces of Parma and Reggio Emilia (North-Eastern Italy; 337,104 registered users). A self-administered anonymous web-based questionnaire was used to collect demographics, knowledge status, perceived risk for contracting meningitis, attitude towards the utility of meningococcal vaccine, and willingness to receive/perform MenB vaccine in their offspring. In total, 541 parents returned a fully completed questionnaire (response rate of 1.6% of potential recipients), with a mean age of 39.2 years ± 6.3 (78.1% females). Meningococcal infection was identified as severe or highly severe by most participants (88.9%), while it was recognized as being frequent/highly frequent in the general population by 18.6% of respondents. The overall knowledge status was unsatisfactory (57.6% ± 33.6 of correct answers to the knowledge test). Even though 63.4% of participants were somewhat favorable to MenB/MenC vaccines, offspring’s vaccination towards MenB was reported by only 38.7% of participants. In a binary logistic regression model, the male gender of respondents (adjusted odds ratio [aOR] 3.184, 95% confidence interval [95%CI] 1.772 to 5.721), living in a municipality >15,000 inhabitants (aOR 1.675, 95%CI 1.051 to 2.668), reporting a favorable attitude on meningococcus B vaccine (aOR 12.472, 95%CI 3.030 to 51.338), having been vaccinated against serogroup B (aOR 5.624, 95%CI 1.936 to 16.337) and/or serogroup C (aOR 2.652, 95%CI 1.442 to 4.872), and having previously vaccinated their offspring against serogroup C meningococcus (aOR 6.585, 95%CI 3.648 to 11.888) were characterized as positive effectors of offspring’s vaccination. On the contrary, having a higher risk perception on vaccines was identified as the only negative effector (aOR 0.429, 95%CI 0.241 to 0.765). Our results hint towards extensive knowledge gaps on IMD and preventive interventions in the general population, suggesting that a positive attitude towards vaccines and vaccinations could be identified as the main effector also for MenB acceptance. Interventions in the general population aimed at improving confidence, compliance, and acknowledgment of the collective responsibility, as well as preventing actual constraints and the sharing of false beliefs on infectious diseases and their preventive measures, could therefore increase vaccination acceptance in both targeted individuals and their offspring.

COVID-19 and Seasonal Influenza Vaccination: Cross-Protection, Co-Administration, Combination Vaccines, and Hesitancy

SARS-CoV-2 and influenza are the main respiratory viruses for which effective vaccines are currently available. Strategies in which COVID-19 and influenza vaccines are administered simultaneously or combined into a single preparation are advantageous and may increase vaccination uptake. Here, we comprehensively review the available evidence on COVID-19/influenza vaccine co-administration and combination vaccine candidates from the standpoints of safety, immunogenicity, efficacy, policy and public acceptance. While several observational studies have shown that the trained immunity induced by influenza vaccines can protect against some COVID-19-related endpoints, it is not yet understood whether co-administration or combination vaccines can exert additive effects on relevant outcomes. In randomized controlled trials, co-administration has proved safe, with a reactogenicity profile similar to that of either vaccine administered alone. From the immunogenicity standpoint, the immune response towards four influenza strains and the SARS-CoV-2 spike protein in co-administration groups is generally non-inferior to that seen in groups receiving either vaccine alone. Several public health authorities have advocated co-administration. Different combination vaccine candidates are in (pre)-clinical development. The hesitancy towards vaccine co-administration or combination vaccines is a multifaceted phenomenon and may be higher than the acceptance of either vaccine administered separately. Public health implications are discussed.