J&J single-shot vaccine found 66% effective in phase 3 clinical trials; what this means

J&J is using its flagship AdVac vaccine platform , which was also used to develop and manufacture Janssen’s European Commission-approved Ebola vaccine regimen and construct its Zika, RSV, and HIV investigational vaccine candidates. Janssen’s AdVac vectors are based on a specific type of adenovirus — one genetically modified so that it can no longer replicate in humans and cause disease.

The phase 3 trial is being conducted in eight countries across three continents — with 44% (19,302) of the participants in the US, 41% (17,905) in Central and South America (Argentina, Brazil, Chile, Colombia, Mexico, Peru) and 15% in South Africa. Nearly one-third (14,672) are over age 60.

“Efficacy against severe disease increased over time with no cases in vaccinated participants reported after day 49,” J&J said. It said the candidate demonstrated “complete protection” against Covid-related hospitalization and death, 28 days post-vaccination. “There was a clear effect of the vaccine on Covid-19 cases requiring medical intervention (hospitalization, ICU admission, mechanical ventilation, extracorporeal membrane oxygenation (ECMO), with no reported cases among participants who had received the Janssen Covid-19 vaccine, 28 days post-vaccination,” J&J said.

On safety, J&J said that overall fever rates were 9% with Grade 3 fever in just 0.2%. “Overall serious adverse events (SAEs) reported were higher in participants who received placebo as compared to the active vaccine candidate. No anaphylaxis was observed,” J&J said.

AstraZeneca in Europe

On Friday, AstraZeneca’s Covid-19 vaccine was recommended for conditional marketing authorisation (CMA) in the European Union. The EU announced that following a renewed request from the European Commission on January 27, AstraZeneca has agreed to publish a redacted contract signed between the two parties on August 27.

The announcement comes after AstraZeneca had announced it would only be able to deliver a fraction of the vaccine doses agreed upon for the first quarter. It claimed there were production problems at its European plants.

According to the contract, all EU member states can purchase 300 million doses of the AstraZeneca vaccine, with an option for a further 100 million doses, to be distributed on a population-based pro- rata basis; the contract also allows the member states to donate their doses to lower and middle income countries or to re-direct them to other European countries.

On Friday, the European Commission said it welcomed the company’s commitment “towards more transparency in its participation in the rollout of the EU Vaccines Strategy”.