Johnson & Johnson one-dose Covid vaccine shown to work

A fifth vaccine, made by the US company Johnson & Johnson, has shown efficacy against the coronavirus and could transform prospects for protecting both the UK and the rest of the world, because it needs only a single dose.

The vaccine, made by the US giant’s subsidiary Janssen, based in the Netherlands, was trialled in the UK – and the British government has bought 30m doses. The EU has ordered 400m doses.

The company said it had 72% efficacy in preventing Covid in the US but a lower rate of 66% was observed globally in the large trial conducted across three continents and against multiple variants.

The results of the trials have been much anticipated, because the Janssen vaccine can be given as a single injection. That means stocks will go further, and particularly in lower-income countries an immunisation programme will be easier as there is no need for a recall after three or 12 weeks.

Results recently published from early trials showed the vaccine triggered a good immune response. Just one shot induced neutralising antibody titers in 96% and T-cell responses in at least 80% of vaccinated volunteers. Some trials are investigating whether a second booster dose confers a useful benefit.

UK vaccine orders

Janssen has agreed in principle to supply up to 500m doses to Covax, the UN initiative to get vaccines to lower-income countries. It is the second biggest order for Covax after the AstraZeneca vaccine.

It is based on a J&J vaccine successfully used against Ebola. It is similar to the Oxford University/AstraZeneca design, but delivers a protein from the spike of the coronavirus through a human common cold rather than chimp adenovirus.

The Food and Drug Administration in the US and the Medicines and Healthcare products Regulatory Agency in the UK have already been looking at the early data and will be expected to make a decision soon on the vaccine’s emergency authorisation.

Three vaccines have so far been authorised by various regulators around the world: those from Pfizer/BioNTech, Moderna and Oxford/AstraZeneca. The European Medicines Agency is expected to approve the Oxford vaccine on Friday. A fourth vaccine, from Novavax, published results from last-stage trials on Thursday and will also now go forward for approval.