The European Medicines Agency (EMA) has issued a positive opinion for Janssen's vaccine, named "COVID-19 Vaccine Janssen". It is the fourth COVID-19 vaccine to be authorised on the market in the European Union. It is the first vaccine requiring only one dose. The positive opinion has yet to be confirmed by the European Commission.
The Committee for Medicinal Products for Human Use (CHMP) of the EMA has thoroughly assessed the quality, safety and efficacy data of the Janssen vaccine and recommended by consensus that the European Commission should grant a formal conditional marketing authorisation for the vaccine. European standards are met and allow for a vaccination campaign in line with European Union (EU) requirements.
Results from a clinical trial with participants from the United States, South Africa and Latin American countries found that COVID-19 Vaccine Janssen was safe and effective for the prevention of COVID-19 in people aged 18 years and older. The study involved over 44,000 participant. Half of the participants received a single dose of the vaccine and half were given a placebo (dummy injection). People did not know if they had been given COVID-19 Vaccine Janssen or placebo.
The trial found a 67% reduction in the number of symptomatic COVID-19 cases after two weeks in people who received COVID-19 Vaccine Janssen (116 cases out of 19,630 people) compared with people given placebo (348 of 19,691 people). This means that the vaccine had a 67% efficacy.
The side effects of COVID-19 Vaccine Janssen were usually mild or moderate and disappeared within a couple of days after vaccination. The most common side effects were pain on the injection site, headache, tiredness, muscle pain and nausea.
Belgium as rapporteur
The authorisation for candidate vaccines always happens via the central European procedure. The EMA appoints one Member State as rapporteur and another Member State as co-rapporteur. For Janssen's vaccine, the FAMHP in Belgium took on the role of rapporteur. Vaccines are one of the FAMHP's spearheads. The agency therefore already has experience as rapporteur and co-rapporteur for the evaluation of non-COVID-19 vaccines.
As for all other medicinal products, the safety and efficacy of COVID-19 vaccines are followed up after they have been marketed. All adverse events are monitored at a national and European level. Janssen's vaccine has been granted conditional marketing authorisation: this means that the manufacturer must provide additional information to the EMA at regular intervals which have been established according to a procedure. In addition, for COVID-19 vaccines, the existing systems for monitoring safety have been extended, both at a national and European level.
Already purchased by Belgium
Subject to market authorisation, Janssens’s vaccine has already been purchased by the Belgian government on 10 October 2020. Five million doses are planned for 2021.
How does COVID-19 Vaccine Janssen work?
The Janssen vaccine is a viral vector vaccine. The vaccine uses a virus that is already known but does not cause disease in humans. This may be an innocuous virus or a live attenuated virus used in another vaccine. In Janssen's case, it is an adenovirus. An antigen (spike protein) or the genetic code of an antigen is added to this viral vector. Some viral vector vaccines can replicate in the host cell (replicating viral vector vaccines), others cannot (non-replicating viral vector vaccines), depending on the changes made to the vector genome. Janssen's vaccine is a non-replicating viral vector vaccines.