I would like to report about my experiences on a study visit at the Rockefeller University, New York City, USA, supported by a European Association of Social Psychology travel grant. Thanks to the EASP travel grant, I was able to collaborate with Ana Milošević, PhD (Laboratory of Molecular and Cellular Neuroscience, The Rockefeller University) on anti-vaccination behavior. During twelve days in April 2018, by taking part in inspiring meetings, brainstorming about existing data and designing and initiating other studies, we generated several plausible hypothesis using data generated so. We also came up with new ideas for future research. Based on an existing study on a representative sample in Serbia. we drafted ideas for another study that will be conducted in the near future in order to test a comprehensive model of explaining anti-vaccination behaviour. All these research investments will lead to a joint research paper. It was both an exciting and valuable exchange of ideas with professionals from different research field.

Vaccine stimulates the immune system to produce the antibodies that further protect the vaccinated person from a certain disease. Health benefits of immunization are well known and backed up by extensive clinical and epidemiological studies. Direct benefits include: reduced diseases and mortality rates; reduction in economic and social burden of disease, reduction in health care cost and work-related productivity loss. The indirect benefit is reduced disease among those who have not been vaccinated. Social benefits of immunization include prolonged life, reduced work absenteeism, safer travel and human mobility, economic growth, promotion of equality, and enabling and strengthening women empowerment.

However, immunization seems to be the victim of its own success. In the past years, the level of immunized people dropped worldwide. On the other hand, effective immunization coverage needs to be above 95 %, both on local and global levels. Besides other factors, unclear media coverage fosters the fear of vaccination, since the risks of immunization receive disproportionately greater media attention than the positive effects. In addition, Internet has made healthcare information generally available, but the status of true and false information is equal, science and pseudoscience are not clearly separated, and experts and amateurs occupy equal space and potentially have equal influence. Thus, it is necessary to build the knowledge about positive effects of immunization, confidence in the health system, create better experience with doctors, and promote positive social norms. It is also imperative to improve the distribution of vaccines and to reduce the prominence of the anti-vaccination movement.

Discussions about the benefits and risks of vaccination are particularly complex in Serbia. The last official report in Serbia indicated a decrease in the immunization coverage in 2015 compared to previous years. Official data shows that 96 % of children age 24-35 months has received all recommended vaccines in 2011, while 84 % of children received all vaccines on time in 2015. The coverage is the lowest for MMR vaccine, but for almost all vaccines the coverage is the lowest in the ten-year period.

The data from national representative survey in Serbia, on the population aged 18+ was analysed during this study visit. One study has already been conducted (November and December 2017), by face-to-face method. Sample size was N=1481 respondents, 341 parents of children younger than seven years, and 698 parents of children younger than 18 years. Second national representative study is planned for May 2018. Analysed variables were: 1. Political anomie; 2. Political cynicism; 3. Political interest; 4. Subjective knowledge of immunization process; 5. Objective knowledge of immunization process; 6. Vaccine conspiracy theories; 7. Trust in science; 8. Social dominance orientation/authoritarianism; 9. Trust in public institutions; 10. Conspiracy mentality; 11. Political orientation; 12. Future vaccination behaviour. The focus in analysis would be: predicting anti-vaccine behaviour; analysing the psychological moderators; clustering the anti-vaccine behaviour by political attitudes.

The study visit was used for:

1. Refining the database, handling the missing data, categorizing true and false responses, and analysing the representativeness of gathered data (based on main socio-demographic variables, comparing the sample and population indicators).
2. Drafting the main findings, clustering the groups of anti-vaccine behaviour and modelling the possible factors influencing the anti-vaccination behaviour. Study revealed a range of different clusters: 1. regular immunization by the calendar with all stipulated vaccines, 2. cautious immunization, accompanied by careful collecting of information, but receiving all vaccines on time, 3. hesitating to vaccinate, being late with some vaccines, 4. selective vaccination (accepting some vaccines, and rejecting others), and 5. complete rejection of all vaccines. Main barriers to vaccination are: fear of side effects; conspiracy theories about the vaccination; mistrust in health system; mistrust in political system (political anomie); conspiratorial mentality; cultural myths about the harmfulness of vaccination;
3. Discussing the future research, planned for the year 2018. We will pay more attention to the connection of anti-vaccination behaviour and different political views. We decided to investigate further emerging problem of distrust in science and to include not only child vaccination but also issues of vaccination of adults. We fine-tuned new questionnaire, exploring the possibilities for including additional variables.

Once again, I am grateful for these academic experiences, and I would like to thank the EASP and especially Sibylle Classen for all her help.