Background and objective:
Vaccination policy in spain is characterised by the decentralisation of national health system. Regional departments of health are the vaccination programmes managers and the Ministry of health, coordinates and oversees. However, a single vaccination strategy against COVID-19 was developed. The objective is to describe the lessons learned from this process and the strategy.

Methods:
Structure, work and decision-making process of the working groups (WG) of the strategy were assessed: the multidisciplinary technical WG for the development of the strategy (which included the national immunization technical advisory group and experts from bioethics, sociology, pharmacovigilance, etc.), WGs on mathematical models, vaccine effectiveness and on the development of the COVID-19 registry. Additionally, results of a survey to the members of the technical WG.

Results:
Recommendations from the technical WGs were not always implemented at political level. Given the uncertainty of the pandemic, the strategy was continuously revised. Having a multidisciplinary team of independent experts and other useful tools for decision-making such as mathematical models, effectiveness studies was essential. COVID-19 vaccination registry is the first single national vaccination registry developed in Spain. It has boosted regional information systems and enabled a real-time monitoring of the vaccination strategy implementation. Vaccination data from all residents was brought together in a homogeneous and standardized way. A lack of technical information suitable to the needs of the population was identified.

Conclusion:
Having multidisciplinary WGs are necessary along with their independence in the decision-making process. Mathematical models and effectiveness studies are valuable tools to revise and improve vaccination policies. High quality information on vaccination implementation programmes is essential to monitor them. Strengthening information systems in public health is critical, notably their flexibility and interoperability. It is necessary to incorporate providing technical communication to the population as an essential element in vaccination strategies.