On 28 May 2021, the MHRA approved the single-shot COVID-19 vaccine produced by Janssen, a subsidiary of US-based pharma giant Johnson & Johnson. This approval follows the approval of the vaccine (on a conditional basis) by the European Medicines Agency.

This is the fourth COVID-19 vaccine to be approved for use in the UK, after those produced by AstraZeneca, Pfizer and Moderna, but is the first which is single-shot. It is as a result of this one-dose regimen that the Janssen vaccine is considered key to tackling the virus globally.

Route to approval

The Janssen vaccine is the first COVID-19 vaccine to be approved in the UK through the grant of a conditional marketing authorisation (cMA), the previous three being granted temporary approval under Regulation 174 of the Human Medicine Regulations 2012 (HMRs).

The Regulation 174 approval pathway allows the MHRA to authorise (on a temporary basis) supply of a medicinal product in response to the spread of pathogenic agents. Unlike the cMA route, there are no formal criteria to be satisfied before the grant of an authorisation under Regulation 174, and there is no formal time limit on an authorisation under Regulation 174. Consequently, the Regulation 174 route is very flexible and there were no precedents for its use prior to the approval of the Pfizer/BioNTech vaccine at the start of December 2020.

The cMA granted by the MHRA to the Janssen vaccine is valid in Great Britain only and was approved via the European Commission (EC) Decision Reliance Route. Approval by this route means Janssen would have applied for a GB marketing authorisation, referencing the EMA’s Committee for Medicinal Products for Human Use (CHMP)’s decision to recommend the vaccine for authorisation in the EU, which was published on 11 March 2021.

It is possible that the links to rare but dangerous blood clots, similarly to the AstraZeneca jab, could have influenced approval being granted through this alternative route.

Development

The Janssen vaccine was developed through the same successful approach used by Johnson & Johnson against Ebola and has similarities to the AstraZeneca vaccine but delivers a protein from the coronavirus using a human common cold vector rather than a chimp adenovirus one. The vaccine was trialled with over 44,000 people in the US, South Africa and Brazil and results suggest it provided 100% protection against hospitalisation and death.

[1] Regulation 174 of the HMRs (as amended)