China's COVID-19 vaccine candidate was found to be safe and induced an immune response in its phase 2 trial, accoding to a paper detailing the study was published in the medical journal The Lancet. 

The results of phase 2 were drawn from a wider group of test patients than the phase 1 trial, which had involved 108 healthy adults. Examiners found promising results. 

"The phase 2 trial adds further evidence on safety and immunogenicity in a large population than the phase 1 trial," said Professor Fengcai Zhu from Jiangsu Provincial Center for Disease Control and Prevention, China. "This is an important step in evaluating this early-stage experimental vaccine and phase 3 trials are now underway."

As detailed on The Lancet, the trial of the Ad5 vectored COVID-19 vaccine involved over 500 participants, conducted in Wuhan. 13% of participants were aged 55 years and above, a quarter aged 45-54 years old, and participants aged 18-44 consisted two-thirds of the total number.

Professor Wei Chen from the Beijing Institute of Biotechnology in Beijing noted that elderly persons face a higher risk of serious illness, which could even lead to death, making them an important target population for the COVID-19 vaccine. It's even possible that the elderly may need another dose of the vaccine in order to ensure a more robust immune response. However, Prof. Chen said further research is needed in order to evaluate this. 

In order to make sure the spread of COVID-19 is stopped, scientists are hard at work to accelerate the development of vaccines and new treatments. As for China, the nation has promised that its vaccine will become a global public good once approved and available. 

Meanwhile, the United Kingdom is also seeing progress in its development of a potential vaccine for COVID-19. The Lancet also published a separate study of Britain's vaccine candidate, revealing the results of the phase 1-2 trial of the Oxford coronavirus vaccine ChAdOx1 nCoV-19. So far, no early safety concerns were raised and the vaccine has induced a strong immune response. 

Oxford University has revealed that the trial involved more than 1,000 healthy volunteers. It was found that its vaccine candidate triggered a T cell response (white blood cells that can attack cells infected with the SARS-CoV-2 virus) within 14 days of vaccination, and an antibody response within 28 days.