This study is not without limitations . First of all , data collection started about a month before any COVID-19 vaccine was officially approved , that is , in a period in which accurate information was not available on the characteristics of the candidate vaccines , in particular about their efficacy , safety , and the possible side effects . With the start of the vaccination campaign , the intention to get vaccinated may likely have changed in light of the clearer information about the vaccines , the experiences of people who have already received them , and , not less importantly , government decisions and the daily news broadcast by the media . As specified above , the data on the time course of the vaccination campaign in Italy are in line with those of the neighbouring countries of the EU ( around 60 % of fully vaccinated people ) . However , the percentage of people still hesitant about the vaccine should not be underestimated , particularly in the older age groups ( e.g. , over 60s and 70s ) , where there is currently the lowest adhesion to vaccines ( Italian Ministry of Health , 2021b ) . For this reason , further studies are needed to verify whether the type of persuasive message that we have identified as the most effective in promoting intention to receive the future COVID-19 vaccine also works in increasing intention to get the currently approved vaccines and the consequent behaviour and its impact on different socio - demographic groups . Secondly , since we used a convenience sample recruited by advertising the study through various online channels ( e.g. , Facebook groups ) , we can not conclude that our results are generalisable to the general population and , above all , that participants did not already have high levels of vaccination intention . However , the heterogeneity of participants in terms of socio - demographic characteristics may have partially reduced this bias . Thirdly , although in the literature there is no convincing evidence that affective attitudeunlike anticipated affective reactionscan predict vaccination intention , future studies with larger samples could simultaneously manipulate both components of the attitude ( cognitive vs affective ) plus anticipated affective reactions to clarify better if and how these processes are mutually exclusive in the context of the decision - making process related to COVID-19 vaccination . In addition , it should be noted that we have not focused on all the variables of the TPB model but only on attitude and intention . Future studies should also consider , for example , the possible effect of subjective norms on the intention to get vaccinated against COVID , since the literature shows that subjective norms , after attitude , are the strongest predictors of vaccination intentions ( e.g. , Askelson et al . , 2010 ) . Injunctive norms , i.e. what significant others ( family , friends ) think the person should do ( to get vaccinated or not ) , and descriptive norms , i.e. what they do themselves ( they intend to get vaccinated or not ) , are both aspects that could have a substantial impact on the decision to get vaccinated , especially in consideration of the context of uncertainty ( e.g. , doubts about the safety and efficacy of the vaccines ) in which this decision is taken . Furthermore , considering that many countries are starting to vaccinate or consider vaccinating children and young people , studying the impact of social influences is even more relevant . Indeed , younger people 's attitudes toward vaccines appear to be heavily influenced by social norms ( Rambout et al . , 2014 ) ; in this perspective , learning that most people significant to them ( e.g. , parents or friends ) get vaccinated can represent , for the youngest , an important motivational factor .