Introduction
The COVID-19 pandemic, which emerged in late December 2019 in Wuhan, China ( Poland, 2020 ), continues to impact people around the world, with more than 755 million confirmed cases and more than 6.8 million deaths reported to the World Health Organization (WHO) as of February 10, 2023 ( World Health Organization, 2023a ). Despite the US Food and Drug Administration’s approval of two types of treatments available to date, which are antiviral treatment with remdesivir and immunomodulatory therapy with barcitinib and tocilizumab, vaccination remains one of the best health protection measures to prevent COVID-19 ( Wang et al., 2020 ; U.S. Food and Drug Administration, 2022 ). In the context of the current pandemic, vaccines were developed to lessen the impact of infection by the new coronavirus ( Urrunaga-Pastor et al., 2021 ).

However, the success of vaccination programs depends on the efficacy and safety of the vaccine, and on the willingness of individuals to be vaccinated ( Sallam, 2021 ; Neumann-Böhme et al., 2022 ). This disposition can be negatively affected by various sociodemographic and sociological elements, such as political trends, which poses a major challenge to global efforts to prevent and control infection ( Herrera-Añazco et al., 2021a ). The willingness of people to be vaccinated varies and includes acceptance, hesitancy or total refusal of the vaccine. In public health, it is very important to intervene with people who are hesitant because, unlike people with complete refusal, it is more likely that through good communication, understanding of their doubts and concerns, as well as taking into account the country context and the limitations of access to health services, it is possible to change to a state of acceptance of the vaccine ( Dubé & MacDonald, 2022 ). This issue has led to studies around the world on the intention to be vaccinated (IBV) against COVID-19, among which a systematic review showed the existence of regional variability, indicating uptake rates below 60% in the Middle East, Eastern Europe and Russia ( Sallam, Al-Sanafi & Sallam, 2022 ), and high uptake rates above 90% in East and Southeast Asia ( Sallam, 2021 ), representing a problem in the successful implementation of vaccination programs globally.

One of the places most affected by the COVID-19 pandemic was Latin America and the Caribbean, finding a relatively high IBV with the first scheme (80%), with the highest prevalence in Mexico (88%) and the lowest in Haiti (43%) ( Urrunaga-Pastor et al., 2021 ; Sallam, 2021 ). The opposite is true for the booster dose, since a study conducted in this population between February and March 2022 found that 33.7% of participants had not received the COVID-19 booster dose ( Urrunaga-Pastor et al., 2022 ). Vaccination in Peru against COVID-19 began in February 2021, prioritizing the immunization of health personnel, then, in the following months, continued by age groups from oldest to youngest, namely “80 years and older”, “70 to 79 years”, “60 to 69 years” until reaching the age of “12 to 19 years”, who were also considered, in the same year, as a target group for immunization ( Ministry of Health of Peru, 2023b ; Sociedad Peruana de Urología, 2023 ). In Peru, IBV with the first dose was found to be 74.9% ( Sallam, Al-Sanafi & Sallam, 2022 ). One of the primary reasons for not receiving the vaccine is the fear of potential adverse effects of immunization ( Urrunaga-Pastor et al., 2021 ). Similarly, research on IBV with booster doses in the same country found that, as of April 2022, 21.5% had not receive a booster dose ( Bendezu-Quispe et al., 2022 ). The Peruvian health situation room, as of February 05, 2023, has reported 4,482,582 confirmed cases of COVID-19 and 219,195 deaths ( Covid 19 en el Perú Ministerio de Salud, 2023 ). According to the vaccination schedule of the Repositorio Único Nacional de Información en Salud (REUNIS), a total of 87,496,729 doses of vaccines have been applied until February 12, 2023, with coverage of the first and second doses greater than 90%, indicating a high acceptance of primary vaccination, probably because the ravages and consequences experienced by the pandemic in Peru were one of the most devastating in Latin America ( Garcia et al., 2020 ). However, the third and fourth doses on the same date have a coverage of 74.1% and 26.0%, respectively, which probably implies a lower acceptance of the booster dose ( Ministry of Health of Peru, 2023a ). Although research related to IBV with both first and booster doses has been conducted in our country, we consider that the vaccination campaign needs continuous monitoring in order to identify factors that can be intervened to improve vaccination in Peru. Therefore, the objective of the present study was to explore the factors associated with the intention to be vaccinated with the booster dose against COVID-19 in Peru.