The Paul-Ehrlich-Institut, Federal Institute for Vaccines and Biomedicines has authorised another Phase-1 clinical trial of a vaccine against COVID-19 in Germany. The new vaccine candidate is a so-called vector vaccine. Trials on vaccine candidates in humans are a significant step in the direction of authorising safe and efficacious vaccines against COVID-19.

This new vaccine is a vector vaccine developed by the German Center for Infection Research (Deutsches Zentrum für Infektionsforschung, DZIF) and the IDT Biologika GmbH against SARS-CoV-2. In this vector vaccine, the genetic information for the spike surface protein of the SARS-CoV-2 virus is built into the smallpox vaccine virus MVA. The starting vaccine virus MVA was already developed more than 30 years ago at the Ludwig-Maximilians University (LMU) in Munich, and the authorised smallpox vaccine Imvanex was derived from it. The viral vector MVA equipped with the genetic information of SARS-CoV-2 cannot replicate in the body after injection. The genetic information (desoxyribonucleic acid, DNA) of the spike protein of the virus thus inserted is used in the body to form the spike protein. The immune system recognises the foreign spike protein and triggers an immune response. The aim is to generate antibodies, certain cytokines and immune cells (T cells) for lasting protection against SARS-CoV-2. Preclinical models at the universities of Marburg and Munich have already shown that the MVA vector vaccine against SARS-CoV-2 shows the desired immune responses and a protective effect.

The clinical trial authorised by the Paul-Ehrlich-Institut on 30 September 2020 is a phase 1 clinical trial with altogether 30 healthy subjects aged between 18 and 55 years. The participants receive two vaccinations at an interval of four weeks. The working group at the University Medical Center Hamburg-Eppendorf (UKE) and the DZIF partner in Marburg are simultaneously measuring the formation of antibodies and T cells in the body and comparing them with the immune response of recovered COVID-19 patients. The UKE is responsible for the clinical trial, which is carried out jointly with the contracted medical institute CTC North. The study is financed by public funds from the DZIF.

According to the World Health Organisation (WHO), as per 30 September 2020, the vaccine candidate is one of the 41 preventive specific COVID-19 vaccine candidates being evaluated in clinical trials. In Germany, it represents the first authorised phase 1 clinical trial for a vector-based COVID-19 vaccine. The increasing number of clinical trials worldwide is an important step toward authorising safe and efficacious COVID-19 vaccine products.

The Paul-Ehrlich-Institut, which is the competent authority for authorising clinical trials and the evaluation and marketing authorisation of vaccines in Germany, expects additional clinical trials for COVID-19 vaccine candidates to start in Germany in the next few months. The Paul-Ehrlich-Institut supports the worldwide COVID-19 vaccine development with top priority.

Background for Vector Vaccines

COVID-19 vector vaccines contain innocuous parts of the genome of SARS-CoV-2 in their genetic information, i.e. the blueprint for the spike protein or for a component of that spike protein. After this genetic information has entered a few body cells of the vaccinated subject, it is read (like the genetic information of the body cells itself) in the cells as messenger RNA, and the appropriate surface structures (proteins) of the virus are produced. The immune system reacts to the foreign protein thus formed and forms defences against it (among other things antibodies). If the person thus vaccinated comes into contact with SARS-CoV-2 later on, the immune system will recognise the surface structure with the aim to prevent or alleviate a serious course of a COVID-19 infection, and even to reduce the transmission of SARS-CoV-2 from human to human.