The vaccine showed immune responses consistent with those measured in people recovered from Covid-19, in all adult age groups


Sanofi, GSK Covid-19 vaccine candidate. (Credit: pearson0612 from Pixabay.)

Sanofi and GSK announced that their adjuvanted recombinant Covid-19 vaccine candidate has showed strong neutralising antibody responses in a Phase 2 study.

The randomised, double-blind, multi-centre, dose-ranging study was conducted in 722 healthy adults, aged 18 years of age and older, including high-risk medical conditions.

In the Phase 2 study, the vaccine showed immune responses, in all adult age groups, consistent with those measured in people recovered from Covid-19.

Interim results from the Phase 2 trial showed that the vaccine induced 95% to 100% seroconversion after the second dose, with no safety concerns and acceptable tolerability.

Sanofi Pasteur executive vice president and global head Thomas Triomphe said: “Our Phase 2 data confirm the potential of this vaccine to play a role in addressing this ongoing global public health crisis, as we know multiple vaccines will be needed, especially as variants continue to emerge and the need for effective and booster vaccines, which can be stored at normal temperatures, increases.

“With these favourable results, we are set to progress to a global Phase 3 efficacy study. We look forward to generating additional data and working with our partners around the world to make our vaccine available as quickly as possible.”

Under the partnership, Sanofi offers its recombinant antigen and GSK its pandemic adjuvant, both vaccine platforms that have been successful against influenza.

Based on the positive Phase 2 interim results, Sanofi and GSK are planning to commence a global Phase 3 study with the 10µg dose, in few weeks.

The Phase 3 trial will enrol more than 35,000 adult participants to evaluate the efficacy of two vaccine formulations including the Wuhan (D614) and South African (B.1.351) variants.

Also, the companies intend to conduct booster studies with different variants to assess the capability of a lower vaccine dose to generate a strong booster response, regardless of the initial vaccine platform received.

The vaccine candidate is expected to be approved in the fourth quarter of 2021, pending positive Phase 3 outcomes and regulatory reviews.

GSK Vaccines president Roger Connor said: “These positive data show the potential of this protein-based adjuvanted vaccine candidate in the broader context of the pandemic, including the need to address variants and to provide for booster doses.

“We believe that this vaccine candidate can make a significant contribution to the ongoing fight against Covid-19 and will move to Phase 3 as soon as possible to meet our goal of making it available before the end of the year.”