Most vaccinated people still respect the rules

April 6th 2021

Big Corona study confirms that young adults experience relatively more vaccine side effects 

People who have already received their vaccine seem to continue to comply to the measures. The three most commonly reported side effects of the vaccines are fatigue, soreness or swelling at the injection site, and headaches. This and more was found in a new wave of the Big Corona Study. 

For the 34th time, scientists presented the Big Corona Study to the general public last Tuesday. The public responded eagerly again, as just under 22,000 people – about the same as two weeks earlier – completed the questionnaire. The Big Corona Study is an initiative of UAntwerp, in cooperation with UHasselt, KU Leuven, ULB and supported by a financial boost from the Research Foundation Flanders (FWO). 

From the enormous amount of data, the researchers produced the following results from an initial analysis: 

  • 18% of participants in the 34th edition of the Big Corona Study have received at least one dose of the vaccine. About three quarters of participants say that they still strictly adhere to the measures after getting vaccinated. This is apparent from, for example, the percentage of participants who have recently shaken hands with or kissed someone outside their own household. But we do see the usual age gradient, with older adults more likely to report strictly complying to the rules than younger adults. The relation between being vaccinated and social distancing seems to be less relevant so far. The sample of minors is small in this questionnaire, so the scientists can’t make any statements about them. The number of adults who have already received a second dose is, of course, still fairly small at this stage, but the small number still allows for cautious interpretations (18–35 years: 179 participants; aged 36–65: 1071 participants; 66+: 264 participants).  

  • Young adults report experiencing side effects more often than other age groups. 23.2% of 18–35 year-olds said they felt their symptoms were severe. Among 36–65 year-olds, it is 11.8%; among 66+ year-olds only 1.2%. Fatigue, soreness or swelling at the injection site, and headaches are the three most commonly reported side effects. These findings are in line with the results of several phase 3 vaccine studies.  

  • In terms of trust, it again appears that the participants place the most trust in scientific experts to deal with the COVID-19 crisis, followed by the pharmaceutical sector (to supply vaccines), and the city/municipal and federal governments.  

In one year, the Big Corona Study has produced an incredible collection of data. ‘But this data is only valuable if it is interpreted in the right way statistically’, Prof. Thomas Neyens (KU Leuven) says. ‘We know that our sample is not fully representative of the Belgian population, but using statistical corrections we can still make meaningful statements. We are very pleased with the large number of participants, but there are significantly more Flemish than Walloon respondents. The statistics for French-speaking Belgium are therefore more uncertain than those for Flanders.’ In this contribution the scientists frame the statistical interpretation of the Big Corona Study.