J&J "Janssen Vaccine Shows Strong Immune Efficacy Against Delta Variant" (Comprehensive Report 2)

Announcement of In-House Clinical Trial Analysis Results
"Immune Efficacy Lasts at Least 8 Months"

[Image source=EPA Yonhap News]

[Asia Economy Reporter Kim Suhwan] Johnson & Johnson (J&J) announced on the 1st (local time) that its pharmaceutical subsidiary Janssen's COVID-19 vaccine has strong immune efficacy against various variants, including the Delta variant.

In a press release on the same day, J&J stated that the Janssen vaccine has immune efficacy against the Delta variant virus, and that the immune response of vaccinated individuals lasted for at least 8 months.

J&J said that an analysis of the Phase 3 clinical trial data of the Janssen vaccine showed that the neutralizing antibody activity induced by this vaccine against the Delta variant was at a high level.

'Neutralising' refers to the defensive action of antibodies that block the virus from invading cells.

J&J also explained that the efficacy against the Delta variant was much higher than the immune efficacy against the Beta variant originating from South Africa.

Dr. Paul Stoffels, Vice Chairman of the J&J Board and Chief Scientific Officer (CSO), said, "We believe our vaccine provides sustained protection against COVID-19 and induces neutralizing antibody activity against the Delta variant as well."

J&J stated that at 8 months after vaccination, the average neutralizing titer of this vaccine was measured to exceed the neutralizing titer at 29 days post-vaccination. Generally, the higher the antibody titer, the stronger the defense against COVID-19 is known to be.

In other words, it means that the effect of neutralizing the Delta variant appears from at least 29 days after vaccination.

Additionally, the company added that the vaccine's immune response lasts for more than 8 months after vaccination, and the duration may be extended further.

The company also reported that the Janssen vaccine was evaluated to have 85% efficacy in preventing severe disease with just one dose against COVID-19.

Unlike vaccines such as Pfizer, Moderna, and AstraZeneca, which require two doses, the Janssen vaccine is administered only once.

J&J announced that it has posted two related papers, which have not yet undergone peer review, on the preprint server 'bioRxiv'.