Public health officials are addressing a surge in questions regarding vaccine mandates, particularly following recent expansions in recommended ages for meningococcal ACWY and B vaccinations. The obligation to vaccinate applies to all children, encompassing infants following standard schedules—primary vaccination series plus boosters—and catch-up programs as outlined by health authorities. Verification of vaccination status is typically conducted upon entry into collective settings like schools and daycare centers. Recognizing potential for misinterpretation of the regulations, experts at InfoVac have released a detailed analysis, available here, prepared with legal counsel to provide clarity for both healthcare professionals and families.
Alongside the discussion of mandates, a critical reminder has been issued regarding vaccine administration: the practice of mixing two different vaccines within the same syringe is strictly prohibited. The French National Agency for the Safety of Medicines and Health Products (ANSM) has reported recent instances of this inappropriate practice, and InfoVac is receiving numerous inquiries about it. This method, while seemingly convenient, can significantly increase the risk of local or systemic reactions and, crucially, may diminish the immune response to one or both vaccines. Any injection administered in this manner should not be considered valid, and all doses must be repeated.
Winter Epidemics Waning, Timing Critical for Immunization
The peak of the winter epidemics of respiratory syncytial virus (RSV) and influenza appears to be subsiding. Initiating immunization against these viruses at this stage offers limited benefit for both children and adults. However, ongoing monitoring of these trends remains essential for future public health strategies.
RSV Vaccination Strategies Under Review
Data from the French National Network of Sentinel Practices (PARI) and Santé publique France indicate that the recent RSV epidemic, in terms of bronchiolitis cases requiring both outpatient and hospital care, was comparable in intensity to the previous year. This observation is particularly noteworthy given the increased coverage achieved through maternal vaccination. Previous InfoVac bulletins highlighted findings from the EPIPHARE study, which demonstrated that the real-world effectiveness of maternal RSV vaccination in France—administered between 32 and 36 weeks of gestation, with campaigns beginning September 1st—was lower than that observed with monoclonal antibodies.
However, recent studies conducted in the United Kingdom (Wilson M et al RESVINET2026) and Australia (Wadia U et al. RESVINET 2026) suggest that initiating vaccination as early as the 28th week of gestation, coupled with sufficient time between vaccination and the onset of the epidemic season, can significantly improve efficacy, exceeding 80%. These findings align with preliminary data currently being analyzed in France. Authorities are expected to consider these new findings when formulating future vaccination strategies, as maintaining the current approach would likely be inadvisable.
Flu Season Insights: H3N2 Clade K Dominance and Vaccine Effectiveness
This influenza season has seen limited cases of influenza B and A(H1N1) pdm09. The A(H3N2) clade K subtype has been overwhelmingly dominant, according to reports from Santé publique France. Despite increasing vaccination coverage, the epidemic was early and relatively intense, though less severe than the previous year. This is partially attributed to the modest vaccine efficacy against this particular strain, a common challenge with evolving H3N2 variants.
| Country | Event Type | Age Group | Vaccine Efficacy (CI95%) |
| France | Outpatient Consultations | 0 – 17 years | 57% (29–74) |
| France | Outpatient Consultations | 18 – 64 years | 45% (36–53) |
| France | Outpatient Consultations | ≥ 65 years | 28% (17–37) |
| England | Emergency Department Visits | 2 – 17 years | 74.8% (66.3–81.4) |
| England | Emergency Department Visits | 18 – 64 years | 32.8% (13.3–48.6) |
| England | Emergency Department Visits | ≥ 65 years | 34.7% (22.2–45.3) |
As is typical, vaccine efficacy is higher in children than in young adults, and higher in young adults than in older adults. The superior efficacy observed in English children is linked to the use of the nasal spray vaccine, while France relies on the injectable form. The availability of a nasal vaccine could potentially increase vaccination rates, even with comparable efficacy.
Robert Cohen, François Vie le Sage, Georges Thiebault, Christophe Batard, Pierre Begué, Marie-Aliette Dommergues, Véronique Dufour, Joël Gaudelus, Isabelle Hau, Cécile Janssen, Maeva Lefebvre, Didier Pinquier, Anne-Sophie Romain, Franck Thollot, Catherine Weil-Olivier, Odile Launay, Hervé Haas.
Disclaimer: This article provides information for general knowledge and informational purposes only, and does not constitute medical advice. It is essential to consult with a qualified healthcare professional for any health concerns or before making any decisions related to your health or treatment.
The evolving landscape of respiratory viruses and vaccine strategies requires ongoing vigilance and adaptation. The next key update from health authorities is expected in late spring, following a comprehensive review of the 2025-2026 season’s data and the latest research on RSV and influenza vaccination. Share this information with your network and join the conversation about public health preparedness.
