Pharmaceutical giants Sanofi and Glaxo Smith Kline (GSK) on Thursday started a clinical trial for their jointly developed Covid-19 vaccine candidate.A total of 440 healthy adults are being enrolled in the trial across 11 investigational sites in the US, the two drugmakers said.The vaccine candidate uses the same recombinant protein-based technology as one of Sanofi's seasonal influenza vaccines with GSK's pandemic adjuvant technology.The Phase 1/2 clinical trial is a randomised, double blind and placebo-controlled trial designed to evaluate the safety, tolerability and immune response of the Covid-19 vaccine candidate.The companies anticipate first results early December which will support the initiation of a Phase 3 trial in the same month.If data are sufficient for licensure application, the plan is to request regulatory approval in the first half of 2021, French pharma company Sanofi and its British peer GSK said, adding that the two companies are scaling up manufacturing of the antigen and adjuvant with the target of producing up to one billion doses in 2021."Sanofi and GSK bring proven science and technology to the fight against the global Covid-19 pandemic, with the shared objective of delivering a safe and effective vaccine," Thomas Triomphe, Executive Vice President and Global Head of Sanofi Pasteur, said in a statement."The initiation of our clinical study is an important step and brings us closer to a potential vaccine which could help defeat Cocid-19."Preclinical data showed an acceptable tolerability profile and data based on two injections of the adjuvanted recombinant vaccine showed high levels of neutralising antibodies that are comparable to levels in humans who recovered from the Covid-19 infection, the drugmakers said, adding that pre-clinical results will be published later this year."Moving this vaccine candidate into clinical development is an important moment in the progress towards addressing the global pandemic we are all facing," said Roger Connor, President of GSK Vaccines.Sanofi and GSK said they are committed to making the vaccine available globally.