Initial data for corona vaccine indicate good tolerability but weak immune response

Blog Post Date: Montag 11 Januar 2021

Further development of the MVA-SARS-2-S vector vaccine against COVID-19 by IDT Biologika GmbH and the German Center for Infection Research (DZIF) has been postponed. The vector vaccine was developed by Ludwig-Maximilian-Universität (LMU) in Munich.

Findings of the first clinical testing of the vaccine for safety, tolerability and immunological effectiveness, conducted by University Medical Center Hamburg Eppendorf (UKE) and the Institute of Virology at Philipps University Marburg, are now available. The vaccination is safe and offers good tolerability with a low side effects profile, however, the immune response in the preliminary findings was lower than expected. Clinical testing is set to continue once the reasons for this have been identified.

The MVA-SARS-2-S vector vaccine was administered to 30 test persons in two different dosages up to mid-December. Whilst in preclinical models it displayed robust immune responses and a protective effect, these were less pronounced in the first phase of clinical testing. The causes of this are currently under investigation. The phase II study planned for the beginning of this year has therefore been postponed pending clarification.

“The data that have been evaluated thus far show that immune responses are present but are not generated to the anticipated extent. As we are aware of our high responsibility for the health of the population and a best-possible protective effect for the vaccine, we are now working to optimize it in order to achieve that goal,” says Prof. Dr. Marylyn Addo, the investigator responsible for the clinical study and head of infectiology at the UKE, speaking on behalf of all partners in the consortium.