Vaccine Coadministration in Primary Care: A KAP Survey Among General Practitioners in Southern Italy.

BACKGROUND: The number of vaccines recommended for adults and older people has increased in recent years, and same-visit coadministration represents a potential strategy to improve vaccination coverage and timeliness. However, its implementation in primary care may depend on general practitioners' (GPs) attitudes, vaccination experience, and organisational factors. This study investigated knowledge, attitudes, and practices (KAP) regarding vaccine coadministration among GPs in Apulia, Southern Italy. METHODS: We conducted an anonymous cross-sectional online survey between January and June 2026 among practicing GPs and general practice trainees working in outpatient primary care settings in Apulia. The questionnaire assessed vaccination activity, intended coadministration practices, perceived effects on vaccine effectiveness and coverage, safety in very old adults or patients with multimorbidity, and perceived barriers to vaccination. Descriptive and bivariate analyses were performed, followed by multivariable logistic regression to identify factors independently associated with a positive perception of coadministration safety in very old or multimorbid patients. An additional sensitivity analysis excluded respondents reporting insufficient information to assess safety. RESULTS: A total of 256 physicians completed the survey; 71.1% were aged ≥50 years. Most respondents had administered adult vaccines during the previous year, and 68.0% were classified as high vaccinators, having administered three or more different vaccine types. Although 68.0% believed that coadministration could increase vaccination coverage, only 13.3% reported willingness to administer three or more vaccines during a single visit. Overall, 50.0% considered coadministration very or fairly safe in very old or multimorbid patients, 24.2% considered it slightly or not at all safe, and 25.8% reported insufficient information to assess its safety. In the fully adjusted model, high vaccination activity was associated with higher odds of a positive safety perception (adjusted odds ratio [aOR] 1.93, 95% confidence interval [CI] 1.01-3.70), whereas difficulties using vaccination IT platforms were associated with lower odds (aOR 0.48, 95% CI 0.26-0.86). Age ≥ 50 years was not independently associated with the outcome after adjustment (aOR 0.66, 95% CI 0.35-1.26). CONCLUSIONS: GPs in Apulia showed generally favorable attitudes toward vaccine coadministration, although substantial uncertainty remained regarding its use in very old and multimorbid patients. Confidence in coadministration was primarily associated with greater vaccination activity and fewer difficulties with vaccination IT platforms, whereas age-related differences observed in bivariate analyses were attenuated after multivariable adjustment. Educational, organisational, and digital-support interventions may facilitate broader implementation of same-visit adult vaccination in primary care.