The coronavirus vaccine developed by pharmaceutical company Janssen from Leiden is 66 percent effective, parent company Johnson & Johnson report. 

Leiden coronavirus vaccine 66 percent effective

45.000 people took part in the trials, and Janssen reports that the vaccine was 100 percent effective in preventing hospitalisation and death in coronavirus patients. They also state the vaccine meant 85 percent of those taking part in the trials experienced fewer symptoms if infected with the virus. 28 days after being immunised, 66 percent of those involved in the study were protected from COVID-19.

According to Johnson & Johnson, the vaccine is therefore effective in reducing the risk of moderate or severe illness. However, the Janssen vaccine appears to be less effective against the new South African variant of the virus. The effectiveness of this vaccine is considerably lower than those that have already been approved: both the Moderna and Pfizer/BioNTech vaccines reported around 90 percent efficacy.

Unlike the other vaccines that have already been approved by the European Medicines Agency, the Janssen vaccine is made up of only one dose. The Netherlands has purchased 11,3 million doses of the vaccine.