Since Covid-19 was officially declared a global pandemic, scientists around the world have been racing to develop novel vaccines to combat it. This study—conducted between April 21 and May 10, 2021—characterises the main perceptions, attitudes, and knowledge about Covid-19 vaccination of a sample of Portuguese teachers, health professionals and older adults. These at-risk groups were chosen to participate in the survey because they were the first in line to receive the Covid-19 vaccine in Portugal. The sample was composed of teachers (kindergarten, primary, secondary, and higher education; n=1062), health professionals (physicians, nurses, pharmacists, and dentists; n=890) and non-institutionalised older adults (n=602) (Table 1).

Most of the participants were females residing in the northern, central or Lisbon metropolitan areas of mainland Portugal. The majority of the older adults interviewed only had an education level up to lower secondary (72.8%). In general, all three groups considered themselves to have reasonable to very good health and were up to date on their vaccines (over 90%). However, only around 60% of the health professionals and older adults, and less than half of the teachers had already been vaccinated. Furthermore, around 10% of all participants reported that they were not willing to receive the vaccine when it becomes available to them.

Participants were asked about their views of Covid-19 infection and the importance of taking the vaccine (graph 2). Over 75% of the participants from the three groups agreed or strongly agreed that getting vaccinated would reduce their probability of getting Covid-19 or suffering associated complications. Although around 85% of the teachers and health professionals perceived the high importance of getting vaccinated, even after being infected with Covid-19, only 64% of the older adults (≥ 65 years old) shared this view. Over 20% of the teachers and health professionals did not perceive that the vaccine would protect them from infection or complications, which could be a reason why some of these participants reported an unwillingness to be vaccinated.

A major reason for the high rate of Covid-19 vaccine hesitancy observed in some countries is the concern about vaccine efficacy and safety. Graph 3 indicates that approximately half of the teachers and health professional respondents still hold some reservations regarding the efficacy of the Covid-19 vaccine, while this specific concern was shared by only 35% of the older adults. Similarly, the possibility of side effects following vaccination is a critical worry among teachers (67%) and health professionals (59%), while only around 30% of older adults had this concern. These outcomes may be due to the different types of vaccines administrated to each of these groups or to greater access to information about side effects among people with a higher education level. The study also reveals that 35% to 40% of the teachers and health professionals and nearly 20% of the older adults were concerned about the vaccine’s producer or country of origin, which may represent an obstacle to vaccination (graph 3).

Graph 4 illustrates that a large majority of the respondents trusted the information released by the relevant authorities (such as the Portuguese General Directorate of Health, the Portuguese Health Ministry, the Portuguese National Authority of Medicines and Health Products IP, the World Health Organisation, and the European Medicines Agency). Still, around 20% of teachers and health professionals did not believe this information to be reliable. Participants were much more distrustful of information provided by social media. This difference is especially stark among health professionals (80% who trusted relevant authorities vs. 36% who trusted social media) and is less prominent among older adults (74% vs. 59%). Furthermore, over half of all participants agreed or strongly agreed that they will only take the Covid-19 vaccine if they have sufficient information beforehand (graph 4).

An immune response is produced following natural infection or Covid-19 vaccination, although its levels can vary greatly across individuals. The majority of teachers and health professionals expressed a strong interest in taking a test to detect their immune response after a natural infection (95% and 88%, respectively), or following vaccination (93% and 88%, respectively) (graph 5). On the other hand, only 62% to 65% of the older adults were keen to take an immune response test.

This is an exploratory study of three groups (Portuguese teachers, health professionals and older adults) and, therefore, is not representative of the Portuguese population. The snowball strategy used in this study also limits representativeness among the different groups. There may be a sampling bias among teachers and health professionals, as members of these populations needed Internet access to participate. This problem was avoided in older adults by using telephone interviews, although vulnerable older adults may have been underrepresented. Albeit online questionnaires present limitations, they are cost-effective and quick.

This national-level study assessed Portuguese teachers’, health professionals’ and older adults’ main perceptions, attitudes, and knowledge about Covid-19 vaccination. In general, it shows that while most of the participants perceived the benefits of getting vaccinated, a small but significant proportion of the participants was concerned about vaccine efficacy and side effects, and a smaller proportion planned to refuse vaccination. Overall, the major outcomes are promising, as they reveal good knowledge of and high confidence in Covid-19 vaccination. Nevertheless, concerns about vaccine efficacy and safety, and reported plans to refuse vaccination are disturbing, given that a high level of vaccination is required for the population to reach herd immunity.

ITA, K. (2021). Coronavirus disease (Covid-19): current status and prospects for drug and vaccine development. Archives of Medical Research, 52(1), 15–24. 
KAPLAN, R. M. & MILSTEIN, A. (2021). Influence of a Covid-19 vaccine’s effectiveness and safety profile on vaccination acceptance. Proceedings of the National Academy of Sciences, 118(10), e2021726118. 
LIN, C., TU, P., & BEITSCH, L. M. (2020). Confidence and receptivity for Covid-19 vaccines: a rapid systematic review. Vaccines, 9(1), 16. 
RANDOLPH, H. E., & BARREIRO, L. B. (2020). Herd immunity: understanding Covid-19. Immunity, 52(5), 737–741. 
RAZAI, M. S., CHAUDHRY, U. A. R., DOERHOLT, K., BAULD, L. e MAJEED, A. (2021) Covid-19 vaccination hesitancy. BMJ, n1138.