Sanofi and GlaxoSmithKline delay Covid-19 vaccine, marking setback in global fight against pandemic

Sanofi and GlaxoSmithKline said that clinical trials of their COVID-19 The vaccine showed an insufficient immune response in older people, delaying its launch until the end of next year and marking a setback in the global fight against the pandemic.

Friday’s announcement, which highlighted the challenges of developing vaccines at record speed, hampers efforts to develop the multiple options that experts say the world needs to counter a disease that has killed more than 1.5 million people.

The news, which came on the same day Australia eliminated a national vaccine project, is also a blow to many governments that have booked hundreds of millions of doses of the injection, including the European Union, the United States and Britain.

Shares of France’s Sanofi fell 2.8% at 0910 GMT, while Britain’s GSK was up 0.2%.

The two companies said they planned to start another study next February, hoping to find a more effective vaccine by the end of 2021.

The setback affects one of the most established technologies in vaccines, used against the human papillomavirus, hepatitis B and pertussis, among other pathogens, which aims to introduce laboratory-made proteins into the body to stimulate the immune system to develop a targeted defense against the novel. coronavirus.

It builds leadership for newer approaches used by vaccines from companies like Pfizer-BioNTech and Moderna, which use genetic mRNA technology to trick the body into making those proteins. Both injections were found to be approximately 95% effective in large-scale successful trials.

The delays and additional trials are not unusual, but the Sanofi / GSK announcement highlights the unique set of challenges drug manufacturers face in the science, speed and logistics of multitasking during a pandemic that has crushed global economies. .

It also highlights why governments have spread their bets by securing photos from different developers.

Australia canceled the production of a COVID-19 A vaccine developed by the University of Queensland and using an adjuvant made by the biotech company CSL after trials showed it could interfere with HIV diagnosis.


Sanofi said Friday’s results from the phase I / II trials showed “an immune response comparable to that of patients who recovered from COVID-19 in adults aged 18 to 49 years, but a low immune response in older adults probably due to an insufficient concentration of the antigen ”.

“With this type of vaccine, the result is not a surprise, we know that more antigen is needed in older patients. But when they are in Phase I and II, drug manufacturers test tolerance and strong doses cannot be tested, ”said Jean-Daniel Lelievre, chief of clinical immunology and infectious diseases at Henri-Mondor hospital in Creteil, France.

“I think Sanofi and GSK will be able to improve their vaccine.”

Phase III studies were expected to begin this month. However, Sanofi said it would launch a phase 2b study in February instead.

“The study will include a proposed comparison with a COVID-19 vaccine, “the company said, declining to give further details.

“If the data is positive, a global phase III study could begin in the second quarter of 2021. The positive results of this study would lead to regulatory filings in the second half of 2021, delaying the potential availability of the vaccine from mid-2021. from 2021 to the fourth quarter of 2021 “.

The two companies said they had “updated governments and the European Commission where a contractual commitment has been made to buy the vaccine.”


The vaccine uses the same recombinant protein-based technology as one of Sanofi’s seasonal influenza vaccines. It will be combined with an adjuvant, a substance that acts as a booster for the vaccine, manufactured by GSK.

Sanofi and GSK have expanded manufacturing to be ready to produce up to 1 billion doses of their vaccine in 2021. GSK said the goal of producing one billion doses of adjuvants was maintained, with some expected to be delivered to other partners in 2021. in place but was under review.

The Phase I / II study tested the vaccine’s safety, tolerability, and immune response in 440 healthy adults at 11 research sites in the United States.

This week Britain began rolling out the Pfizer-BioNTech vaccine, ahead of the rest of the world in the race.

Canada also gave the green light to the vaccine, while a panel of external advisers from the US Food and Drug Administration voted Thursday to support the emergency use authorization.

Rival developers AstraZeneca Plc and Moderna have also reported late-stage data showing their shots are effective in preventing COVID-19.

Sanofi is also working on another vaccine candidate to prevent COVID-19 with the American company Translate Bio, which will rely on a different technology called mRNA, similar to that developed by Pfizer and Moderna. Phase I trials of this vaccine are expected to begin this month.