GlaxoSmithKline PLC (LON:GSK) announced that the COVID-19 vaccine developed with French giant Sanofi SA demonstrated strong immune responses in mid-stage trials.
The jab showed 95% to 100% seroconversion following a second injection in all age groups, with acceptable tolerability and with no safety concerns.
READ: GlaxoSmithKline emerges as unlikely loser of COVID-19 pandemic – but will a return to normality be enough to sort out trouble?
It prompted strong neutralising antibody levels that were comparable to those generated by natural infection, with higher levels observed in adults up to 59 years old.
Participants who previously contracted the virus experienced high antibody levels with the first dose, which the pharma company said suggests strong potential for development as a booster vaccine.
The phase 2 study, involving 722 adults aged 18 to 95 years old, will be followed by a phase 3 trial in the coming weeks.
It will include over 35,000 participants from various countries and will assess the efficacy of two vaccine formulations including the Wuhan and South African variants.
Glaxo and Sanofi expect the vaccine to be approved in the fourth quarter of 2021.