Perceptions on the Importance of Vaccination and Vaccine Refusal in a Medical School

"Medical students and doctors are not adequately vaccinated and have queries about the vaccination schedule, vaccine safety and vaccine refusal. Improving these professionals' knowledge is an important strategy to maintain vaccine coverage and address vaccine refusal ethically."

Vaccine refusal or anti-vaccine groups seem to be rare and few in Brazil, but these few can jeopardise the success already achieved by the National Immunization Program (NIP). Recently, two situations have put the spotlight on the harmful consequences of social networks, which disclosed misinformation about the adverse events of human papillomavirus (HPV) vaccine in Brazilian adolescents and the alleged association of rubella vaccine with microcephaly in infants of Brazilian women possibly infected by the Zika virus. The prompt denial of such rumours and clarification for the population, however, did not prevent the credibility of vaccines from being damaged. Considering that physicians (particularly paediatricians) play central roles in maintaining the credibility of vaccines, the objective of this study was to identify the perception of medical students and physicians on the importance of vaccines and the risks posed by vaccine refusal in São Paulo, Brazil.

The researchers suggest that "The great penetration and easy access to social media has promoted an enormous amount of information - not always correct - on the safety (or unsafety) of vaccines, their effectiveness, efficacy, risks, etc., based on philosophical, political and religious grounds. The proliferation of information of this kind may jeopardize the success of vaccination programs. Knowledge by the health professional with the competence and confidence to clarify the theme can minimize this risk."

The cross-sectional study was based on a questionnaire applied in 2016. The convenience sample, formed by 92 subjects selected from a private medical school (São Leopoldo Mandic School of Medicine and Dentistry, Campinas, São Paulo), was divided into 2 groups: group 1, with 53 medical students (from the first to the fourth grade/year); and group 2, with 39 doctors of different specialties.

Selected findings:

• All physicians and 83% of the students (p=0.0091) agreed with the statement that "vaccines protect against potentially fatal diseases". Most respondents stated that "post-vaccine adverse events are mostly not serious" (92.5% of students and 97.4% of physicians, p=0.390) and that "the benefits of vaccines are much more important" (100% of physicians and 98.1% of students, p=1.00).
• The NIP in Brazil was considered efficient and reliable by 88.7% of students and 92.3% of physicians (p=0.728), but 64.2% of students and 38.5% of physicians are unaware of the vaccine-preventable infectious diseases in the basic immunisation schedule.
• All students and 94.9% of physicians said that had a vaccination registry, but, despite belonging to a group at risk for influenza, 15.4% of physicians had not received the influenza vaccine in 2015; the most commonly reported reason was "lack of interest". Among students, 47.2% had not received influenza vaccine in 2015; the fear of adverse events was cited as the cause of refusal in 16% of occurrences in this group.
• Of the total, 54.7% of students and 59.0% of physicians stated that they know someone who refused to receive vaccines, and 43.4% of the students and 41.0% of the physicians said they know someone who refuses to vaccinate their children. Physicians who said that they had seen one or more patients who refused to receive vaccines during the previous 6 months were 19/39 (48.7%). The conduct described by physicians was always to orient them as to the risks and benefits of vaccination/vaccine refusal. The following reasons were considered possible causes for vaccine refusal by physicians and students, respectively: fear of adverse events (89.7 and 94.3%); philosophical reasons (66.7 and 67.9%); religious reasons (51.3 and 67.9%); and lack of knowledge about the severity and frequency of immunopreventable diseases (43.6 and 43.4%).
• Taking into account a patient who refuses to receive a vaccine (or refuses to vaccinate their children), 43.4% of students and 56.4% of physicians considered it reasonable to respect one's will but said they would explain the consequences of that choice to the patient. Only a minority would think about compulsory vaccination (9.4% of students and 10.3% of physicians) or would stop assisting these patients (13.2% of students and 15.4% of physicians). Most interviewees stated that it is unethical to disregard the risk to other subjects upon vaccine refusal (83% of students and 61.5% of physicians, p=0.003).

The discussion section explores issues raised by the findings, such as the suboptimal (influenza) vaccination of healthcare professionals and the fact that not knowing the potential severity of vaccine-preventable diseases or not knowing the vaccines available at no cost to the population may determine lack of concern with the potential risk of such diseases, and with the individual and collective importance of vaccines among health professionals. Also disconcerting is the finding that 18/53 (34%) of students did not acknowledge the importance of herd protection in controlling infectious diseases. The recent outbreak of measles in the United States, in Brazil, and still persisting in Europe could have been minimised had herd protection been sufficient in the affected populations.

In terms of cultivating that knowledge, the researchers suggest that studies like this one that highlight possible flaws in concepts among this population will be useful when introducing new contents in the teaching programming of immunisations and prevention of infectious diseases. Emphasising discussion on vaccination and its importance in medical school curriculi can empower the future physician for the decision-making process regarding vaccination, approaching vaccination itself, and vaccine refusal in an ethical way, thus maintaining the success obtained with vaccination programmes.