Vaccination Coverage Among Mothers and Close Contacts of Neonates Hospitalized in NICU in Southern Greece: A Cocooning Strategy Approach

Background: Neonates and young infants are susceptible to vaccine-preventable diseases because of immature immune responses and delayed acquisition of vaccine-induced protection. As household members and caregivers are a major source of exposure, international organizations recommend cocooning, i.e., vaccination of susceptible individuals who are in regular contact with infants, to provide complementary indirect neonatal protection. To evaluate cocooning implementation, we assessed influenza and pertussis vaccination uptake among mothers and close contacts of hospitalized neonates and identified factors associated with vaccine uptake. Methods: Mothers of neonates hospitalized in a Neonatal Intensive Care Unit (NICU) between 1 January 2022 and 31 December 2024 were invited to complete a structured questionnaire. Mothers reported their own vaccination status and that of the neonate’s close contacts. Associations between maternal characteristics and vaccine uptake were examined using logistic regression. Results: In total, 405 mothers participated. Influenza vaccination uptake was 47.6% among mothers, and at least one adult close contact was vaccinated in 53.6% of families. Pertussis vaccination uptake was 40.5% among mothers, and at least one adult close contact was vaccinated in 32.3% of families. The most frequently reported reason for non-vaccination was low perceived need among unvaccinated mothers (74.1% for influenza and 83.4% for pertussis) and among families with incompletely vaccinated adult close contacts (81.8% for influenza and 89.7% for pertussis). In multivariable analyses, higher maternal education was associated with increased uptake of both influenza (OR 2.36, 95% CI: 1.47–3.80, p < 0.001) and pertussis vaccination (OR 4.25, 95% CI 2.02–8.94, p < 0.001), whereas younger maternal age (≤25 years) was associated with lower influenza vaccine acceptance (OR 0.24, 95% Cl: 0.1–0.60, p = 0.002). Conclusions: Vaccination uptake among mothers and adult close contacts of NICU-admitted neonates was suboptimal for both influenza and pertussis vaccines. Targeted counseling before delivery, reinforced during maternity or NICU hospitalization as a catch-up opportunity, and system-level implementation measures aligned with the dominant barrier of low perceived need are needed to strengthen cocooning in this high-risk population.