Abstract
This cross-sectional research study aimed to study adverse events and unsafety after receiving types of Covid-19 vaccine. The sample of the study was people with sevem groups of chronic illnesses and older adults who received the Covid-19 vaccine from Ramathiodi Hospital, Bangkok. Purposive sampling was 1,254 cases. Data were collected by face-to-face interview, telephone, or online using the personal questionnaire and the Adverse Events questionnaire. Results showed that almost half of the participants received AstraZeneca+AstraZeneca of 48.79 %. Participants with chronic illnesses and older adults who received the different types of Covid-19 vaccine had the significant difference of adverse events both first dose (χ2=20.21, p<0.001), second dose (χ2=47.7, p<0.001), and the two-dose crossover vaccine (χ2=50.3, p<0.001). The participants who received the two-dose crossover vaccine of Astrazeneca+Pfizer/Moderna had the most adverse events of 67.7%. However, the two-dose from the same group vaccine of Sinovac/Sinopharm+Sinovac/Sinopharm reported only 28% of adverse events. People who were younger than 60 years old with chronic disease had a statistically significant difference in the greatest adverse events compared to healthy older adults with chronic disease who received both the first and second doses of the Covid-19 vaccine (χ2=24.36, p<0.001; χ2=18.31, p<0.001). In addition, Pfizer/Moderna reported the greatest adverse events of 17.4-38.7% such as local symptoms (pain, swelling, redness, hotness, itchy at the injection site), fever, and muscle pain. Moreover, twenty-two participants reported severe adverse events and need to receive first aid and visit the doctor. The results of this study suggested continuing the policy recommendations for vaccination by using the same type of vaccine Sinovac/Sinopharm or AstraZeneca. Using the cross-over type of vaccine is not recommended, especially, in-group of people who were less than 60 years old and had chronic illnesses to decrease adverse events and increase safety.
