The single-dose Covid vaccine by manufacturer Janssen has been authorised for use in the UK, the Government has announced.

The vaccine can be stored at fridge temperatures of +2-8C and was shown to be 66% effective in phase 3 trials earlier this year, the Department of Health and Social Care (DHSC) said.

The Government has secured 20 million doses for use across the UK, which are expected to be available ‘from later this year’, it added.

It was previously announced that 30 million doses had been ordered, but the DHSC today (28 May) said it has ‘decided to amend its original order’ thanks to the ‘unprecedented scale and pace’ of the UK vaccine rollout.

The Government is ‘exploring how best to optimise supply across the current programme’, the DHSC added.

It said: ‘The MHRA has today announced that the Covid-19 Vaccine Janssen meets the expected standards of safety, quality and effectiveness. The independent Commission on Human Medicines (CHM) has reviewed the MHRA’s decision and endorsed it.’

The Joint Committee on Vaccination and Immunisation (JCVI) will submit ‘updated advice’ for the vaccine before doses become available, it added.

Data from the vaccine’s phase 3 trial demonstrated a 67% reduction in symptomatic Covid disease compared with those who received a placebo from 14 days after vaccination, Janssen said.

It also showed the vaccine is 85% effective in preventing severe disease, with a reduction in hospitalisations from 14 days following the jab, the manufacturer added.

Janssen said its vaccine – which has been authorised for use in those aged 18 and over – is ‘estimated to remain stable for two years’ at between  -25C and -15C can be kept at +2 to +8C for up to three months.

The single-dose vaccine is part of a Government-backed study assessing options for a vaccine booster programme, involving a third shot.

The DHSC reiterated that the Government is preparing for a booster programme ‘based on clinical need’ and will publish further details ‘in due course’, with final policy to be informed by JCVI advice and clinical trial results.

Meanwhile, the DHSC said Janssen ‘continues to explore’ a two-dose regimen of its vaccine – which has already been authorised as a single-dose jab by the European Medicines Agency (EMA), the Food and Drug Administration (FDA) and the World Health Organisation (WHO).

Health secretary Matt Hancock said: ‘This is a further boost to the UK’s hugely successful vaccination programme, which has already saved over 13,000 lives, and means that we now have four safe and effective vaccines approved to help protect people from this awful virus.

‘As Janssen is a single-dose vaccine, it will play an important role in the months to come as we redouble our efforts to encourage everyone to get their jabs and potentially begin a booster programme later this year.’

The UK vaccination programme remains ‘on track’ to offer a first Covid jab to all adults by its end of July target, the DHSC added.

Last month, the Janssen vaccine rollout in the US, South Africa and the EU was paused over concerns about links with rare blood clotting.

But the manufacturer today said that a combination of blood clots and low levels of platelets ‘has been observed extremely rarely’.

An assessment of the single-shot jab by the EMA last month concluded: ‘The reported combination of blood clots and low blood platelets is very rare, and the overall benefits of Covid-19 vaccine Janssen in preventing Covid-19 outweigh the risks of side effects.’

The UK Government previously said that the single-dose vaccine ‘would offer a significant advantage’. 

This story first appeared on our sister title, Pulse.