Active Surveillance of Adverse Events After COVID-19 and Other Vaccinations: a Feasibility Study as Part of the CoVaKo Project

Abstract

Background: The Corona-Vakzin-Konsortium project (CoVaKo) analyses the efficacy and safety of COVID-19 vaccines in a real-world setting and breakthrough infections in Bavaria, Germany. A subproject of CoVaKo aims to identify adverse events of the COVID-19 vaccine and to compare these to adverse events of other vaccines in an online survey. A prior feasibility study was conducted to test study materials for comprehensibility, visual design and motivation to participate and secondly, to test practical implementation and realization in primary care practices and vaccination centres.Methods: A mixed-methods design was used. Three focus groups with general population participants were performed to evaluate the study materials and survey. Second, a test-roll-out was conducted in vaccination centres and primary care practices, which involved implementation and quantitative evaluation of the online survey. Third, interviews were conducted with participating general practitioners and heads of vaccination centres four weeks after the test-roll-out.Results: Parts of the study information and registration form proved incomprehensible in the recruitment material and/or online survey. For example, headings were misleading since the COVID-19 vaccination was overemphasized in the title as compared to other vaccinations. Participants requested more information on the procedure and completion time. In 31 days, 2199 participants who received either a COVID-19 vaccination (99 %) or at least one of the control vaccinations (1 %) registered for the study. Participants (strongly) agreed that the registration process was easy to understand, that all relevant information was provided, the completion time was reasonable and technical framework manageable. Physicians and heads of the vaccination centres perceived the study as easy to integrate into their workflow and most of them were willing to participate in the main study.Conclusions: Our study indicated that capturing adverse events after vaccinations with an online survey is feasible. Testing of materials and surveys provided valuable improvements. Participation of health professionals is important to ensure practicality of the procedures. Flexible adaptation of the study organization to changing structures and requirements is necessary for a successful implementation, especially due to dynamic changes in COVID-19 vaccination strategies.Trial registration: The trial was retrospectively registered at “Deutsches Register Klinischer Studien” (DRKS-ID: DRKS00025881) on Oct 14, 2021.

Reactogenicity after heterologous and homologous COVID-19 prime-boost vaccination regimens: descriptive interim results of a comparative observational cohort study

“…In an observational cohort study, reactogenicity and safety of vaccinations were assessed including 14 to 19 days (short-term survey) and 40 to 59 days (long-term survey) after the second COVID-19 vaccination using web-based surveys [ 25 ]. In an interim analysis reactions and health problems after the second dose were compared in individuals with (1) homologous immunization with ChAdOx1 (ChAdOx1/ChAdOx1), (2) heterologous immunization with ChAdOx1 as first dose and BNT162b2 or mRNA-1273 as second dose (ChAdOx1/mRNA), or (3) homologous immunization with mRNA vaccination BNT162b2 or mRNA-1273 (mRNA/mRNA).…”

“…Due to the dynamic changes in vaccination regimens, and the importance of generating real-world evidence on the safety of the different prime-boost regimens, we included both, the data of the feasibility study and the main study in this interim analysis. With only minor changes to the survey between the feasibility study [ 25 ] and main study this approach was considered methodologically valid. All methods were carried out in accordance with relevant guidelines and regulations.…”

Reactogenicity After Heterologous and Homologous COVID-19 Prime-Boost Vaccination Regimens: Descriptive Interim Results of a Comparative Observational Cohort Study

“…In an observational cohort study, reactogenicity and safety of vaccinations were assessed including 14 to 19 days (short-term survey) and 40 to 59 days (long-term survey) after the second COVID-19 vaccination using web-based surveys [25]. In an interim analysis reactions and health problems after the second dose were compared in individuals with (1) homologous immunization with ChAdOx1 (ChAdOx1/ChAdOx1), (2) heterologous immunization with ChAdOx1 as first dose and BNT162b2 or mRNA-1273 as second dose (ChAdOx1/ mRNA), or (3) homologous immunization with mRNA vaccination BNT162b2 or mRNA-1273 (mRNA/mRNA).…”