Johnson & Johnson reveals its Covid vaccine is 66% effective in clinical trial

Johnson and Johnson’s coronavirus vaccine is 66 per cent effective against the disease, early trial results reveal.

And it was shown to prevent severe cases of the virus in 86 per cent of cases – with no participants who were vaccinated needing hospital treatment or dying 28 days after the dose was administered. 

The jab is made by Janssen – the Belgian arm of the US pharmaceutical giant – uses similar technology to the Oxford vaccine, making it easy to transport and store, but requires just a single injection to protect against Covid. 

The UK has ordered 30million doses, with the option of purchasing 22million more, and experts say it could be rolled out in Britain by late February. 

It comes after Novavax announced its jab was 89 per cent effective last night. Both will need to be reviewed by Britain’s medical regulator before they can be deployed.

The figures revealed today show a lower efficacy compared to others reported so far, with Pfizer and Moderna’s both around 95 per cent.

But scientists have said this is still a very good result, with the World Health Organization initially setting the threshold for effectiveness at around 50 per cent. 

The new vaccines could significantly speed up the programme which has been held back by supply shortages. 

Pfizer’s and AstraZeneca’s are the only ones currently being rolled out in the UK and have accounted for the 7million doses given out already.

Another jab, made by US firm Moderna and approved by the British regular, won’t be delivered until March because the UK was late to get its order in.

Janssen said it recorded 468 infections in its phase 3 tests involving more than 44,000 volunteers.

They added it was shown to have slightly less efficacy (57 per cent) in trials in South Africa, where a mutant strain of Covid-19 is feared to make jabs less potent. 

Johnson and Johnson’s early results show variation in the jabs effectiveness between countries. It was up to 72 per cent effective in the US, but this dropped in other areas where trials were carried out.

Hailing the early results in the study, the global research chief for Janssen Dr Mathai Mammen said: ‘Gambling on one dose was certainly worthwhile.’

J&J said it plans to file for emergency use authorisation in the US within a week, before also sending applications abroad.

The Health Secretary Matt Hancock heralded the results as ‘good news’ and said the UK’s approach of securing large vaccine stocks was ‘paying off’.

‘After the good news last night of the effectiveness of the Novavax vaccine that, should it be approved, will be made in Teesside, this lunchtime we just had more good news about the new Janssen vaccine,’ he said.

‘This is a single dose vaccine, and our approach of buying abroad and making here at home is paying off.’

He added: ‘I want to say a huge thank you to everybody involved who’s helped get the UK in this pole position to protect our population and to make sure we get out of this pandemic.’

In the trials, researchers tracked illnesses starting 28 days after vaccination which scientists say is about the time when immunity would be triggered if participants had received a two-dose vaccination instead. 

But amid shortages, some countries have advised delaying the second dose of certain vaccines with little data on how that would affect protection.

All COVID-19 vaccines train the body to recognize the new coronavirus, usually by spotting the spikey protein that coats it. But they´re made in very different ways.

J&J´s shot uses a cold virus like a Trojan horse to carry the spike gene into the body, where cells make harmless copies of the protein to prime the immune system in case the real virus comes along.

Rival AstraZeneca makes a similar cold virus vaccine that requires two doses. Both the AstraZeneca and J&J vaccines can be stored in a refrigerator, making them easier to ship and to use in developing countries than the frozen kind made by Pfizer and Moderna.

It´s not clear exactly how well the AstraZeneca version, being used in Britain and several other countries, works. Tests in Britain, South Africa and Brazil suggested two doses are about 70% effective although there are questions about how much protection older adults get. An ongoing U.S. study may provide more information.

J&J said its vaccine works consistently in a broad range of people: A third of participants were over age 60, and more than 40% had other illnesses putting them at risk of severe COVID-19, including obesity, diabetes and HIV.

J&J said the vaccine is safe, with reactions similar to other COVID-19 shots such as fever that occur when the immune system is revved up.

While it released few details, the company said there were no serious allergic reactions. But occasionally other COVID-19 vaccines trigger such reactions, which can be reversed if promptly treated – and authorities have warned people to be on the lookout regardless of which type of vaccine is used.

J&J had hedged its bets with a study of a two-dose version of its vaccine, which is still underway.

Friday’s interim results come on the heels of another vaccine in final testing. Novavax reported this week that its vaccine appears 89% effective in a U.K. study and that it also seems to work – though not as well – against new mutated versions of the virus circulating in Britain and South Africa. A larger study in the U.S. and Mexico is still enrolling volunteers.

The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute´s Department of Science Education. The AP is solely responsible for all content.