China National Biotec Group (CNBG) is planning late-stage human trials of a potential COVID-19 vaccine after scientists at its Wuhan-based medical facilities noted the experimental drug caused positive antibody responses in 100% of all tested human subjects.
Initial trials for the potentially life-saving vaccine started in April this year. Over 1 100 healthy candidates, aged 18 to 59, were selected as part of the clinical trial by CNBG, an affiliate of parent company, Sinopharm.
Results showed a 100% seroconversion (the process of antibody manifestation) rate after 28 days in the subjects administered a medium dose. The perfect score bodes well for the drug and, while the company didn’t specify the number of antibodies produced by effective vaccination, the state-run group confirmed it observed no serious adverse side-effects.
The Covid-19 pandemic has killed more than 400 000 people globally and, with no working vaccine, the race is on to develop a safe, effective drug.
CNBG’s next step is a mass human efficacy trial. The group confirmed to Reuters that several foreign nations are already looking to cooperate in a late-stage trial.
Trialling the vaccine in an environment where the virus is still circulating is a crucial step. Scientists use this information to establish whether activating the antibodies via vaccine is sufficient to prevent natural infection from occurring.
Bar a recent isolated Beijing spike, China has been free of the virus for some time now so finding candidates for late-stage trials has become difficult. Researchers have had to look abroad for the clinical evaluation of vaccine candidates.
Sinovac, another Chinese medical group, has announced a successful phase two trial. The group observed a 90% efficacy rate in 600 subjects with its vaccine. The drug, an older generation vaccine modelled on existing polio and influenza vaccine technologies, has been picked up by Brazilian drug manufacturer Instituto Butantan. Brazil has the second worst infection rate globally and its doctors, hospitals and morgues have been under severe strain for weeks.
China currently has five ongoing vaccine candidate trials in various stages, the most of any nation. Oxford University’s vaccine candidate has been cleared for trial among 2 000 Brazilian volunteers, while the US’s ‘Operation Warp Speed’ candidates Moderna and AstraZeneca are to introduce large late-stage trials as soon as July.
