Single dose Janssen Covid-19 vaccine 66% effective

29 January 2021, 13:18 | Updated: 29 January 2021, 14:08

A single dose of the Janssen Covid-19 vaccine has proven 66% effective in trials, the Belgian company has announced
A single dose of the Janssen Covid-19 vaccine has proven 66% effective in trials, the Belgian company has announced. Picture: PA

By Kate Buck

A single dose of the Janssen Covid-19 vaccine has proven 66% effective in trials, the Belgian company has announced.

The UK has 30 million doses of the vaccine on order.

The international trial only gave participants one dose of the vaccine, in hopes that it would make it easier to roll out that existing vaccines which need two doses.

Janssen, a pharmaceutical company owned by Johnson & Johnson, is now looking at whether two doses will give stronger or longer-lasting protection.

Read more: Novavax Covid vaccine proves 89% effective in trials - with 60 million doses on order

J&J said on Friday that in the US and seven other countries, the single-shot vaccine was 66% effective overall at preventing moderate to severe illness, and much more protective - 85% - against the most serious symptoms.

There was some geographic variation.

The vaccine worked better in the US - 72% effective against moderate to severe Covid-19 - compared with 57% in South Africa, where it was up against an easier-to-spread mutated virus.

"Gambling on one dose was certainly worthwhile," Dr Mathai Mammen, global research chief for J&J's Janssen Pharmaceutical unit said.

The company said within a week, it will file an application for emergency use in the US, and then abroad.

It expects to supply 100 million doses to the US by June, and expects to have some ready to ship as soon as authorities give the green light.

These are preliminary findings from a study of 44,000 volunteers that is not completed yet.

More to follow...