With Johnson & Johnson (J&J) and Novavax, two more companies presented Covid-19 vaccine efficacy data last week. With an efficacy of 66%, J&J’s vaccine is hardly the most efficacious regimen but will be the agent of choice for controlling the outbreak, since a single dose of the vaccine protects against hospitalisation and death from Covid-19.
Novavax’s candidate showed a more potent efficacy of 89.3% with two doses, but potentially twice as many people can get vaccinated with J&J’s vaccine in the same time frame. Additionally, countries may adopt a policy being proposed by Germany: use more potent vaccines from Pfizer / BioNTech, Moderna, and Novavax in high-risk groups, while vaccinating the general population with whatever vaccine is available to control the overall spread. J&J is still testing a two-dose regimen, so it still has the potential to compete with the current leaders in terms of overall efficacy, but these data will only be available in a few months.
J&J’s adenovirus vector-based vaccine, developed by its subsidiary Janssen Pharmaceuticals, reported 66% overall vaccine efficacy with a single dose after 28 days in a global Phase III trial with 43,783 participants. However, efficacies were different at different trial locations: 72% efficacy in the US, 66% in Latin America, and 57% in South Africa, the latter in which many cases were caused by the new SARS-CoV-2 variant B.1.351.
J&J’s vaccine was 85% overall effective in preventing severe disease and demonstrated complete protection against Covid-19-related hospitalisation and death 28 days after vaccination. J&J is planning to apply for emergency use authorisation (EUA) in the US in early February and expects that vaccine distribution can start directly after regulatory authorisation. The company has supply agreements for 200 million doses with the EU and for 100 million doses with the US government.
Novavax’s Covid-19 vaccine NVX-CoV2373 showed 89.3% efficacy in a Phase III UK trial with 15,000 participants. A total of 62 Covid-19 cases were observed, 56 in the placebo group and six in the vaccine group, with 50% of cases from the B.117 variant found in the UK, showing good protection against the new variant. The vaccine was only 60% effective in a separate Phase IIb trial in South Africa with 4,400 participants. Many of the Covid-19 cases in this trial were caused by the new SARS-CoV-2 variant B.1.351 first found in South Africa.
Furthermore, one-third of the South African trial participants had previous SARS-CoV-2 infections. In 6% of trial participants who were HIV-positive, the vaccine showed 49.4% efficacy. NVX-CoV2373 is a recombinant nanoparticle of the SARS-CoV-2 spike protein with a saponin-based adjuvant. Assuming similar regulatory processes as for Pfizer / BioNTech’s and Moderna’s COVID-19 vaccines, GlobalData expects first authorisation of Novavax’s vaccine in the UK, while the EU’s approval process is slower. The FDA will likely wait for trial results from the US, where the Phase III trial started three months later than in the UK.
However, as more and more Covid-19 vaccines become available, increased scrutiny will be placed on the fifth, sixth, and later vaccines to enter the market. Eventually, enough real-world data will be had to determine that one vaccine might be best for controlling the outbreak, while another vaccine offers the best overall protection in high-risk groups, and another is best for use in the general population. Considering vaccine distribution to countries with less developed healthcare infrastructure, a combination of acceptable efficacy, good protection in high-risk groups, and ease of distribution by being more stable at lower temperatures, such as vaccines from AstraZeneca, Novavax, and J&J, will be equally important.