GlaxoSmithKline (GSK.L) reported a second set of optimistic results in its coronavirus vaccine trials in as many days on Tuesday, saying it had seen "positive interim phase 2 clinical trial safety and immunogenicity data" in its link-up with Medicago.
Its vaccine candidate has produced a similar antibody response in adults and in the elderly after two doses, it said.
It also said that neutralising antibody responses were ten times higher than in people recovering from COVID-19.
Alongside this, no related severe adverse events have been reported in conjunction with the trials.
GSK is a FTSE 100 (^FTSE) drugs giant worth about £69bn ($97bn) and employing 94,000 people.
Despite its size, it has been something of a laggard in the race to produce a coronavirus vaccine, with several other candidates moving to mass-production and worldwide rollout first, including Pfizer (PFE), the Oxford-AstraZeneca (AZN.L) effort and Moderna (MRNA).
"These results give us confidence as we continue to move forward with our Phase 3 clinical trial. We hope to add another tool in the global fight against COVID-19, particularly as cross-protection emerges as an important consideration in vaccination efforts worldwide," said Nathalie Landry, executive vice-president, scientific and medical affairs at Medicago.
On Monday, GSK and Sanofi (SNY) reported strong results, saying the jab it is developing had "triggered strong neutralising antibody responses in all adult age groups."
"Overall, the vaccine candidate elicited strong neutralising antibody levels that were comparable to those generated by natural infection, with higher levels observed in younger adults (18 to 59 years old)," it said.
Phase 3 trials are expected to start in the coming weeks.
The phase 3 trial is expected to enrol more than 35,000 adult participants from a broad range of countries and will assess the efficacy of two vaccine formulations including the D614 (Wuhan) and B.1.351 (South African) variants.
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