In a study of 4,000 participants, the vaccine showed efficacy of 85.3 percent 14 to 28 days after a booster vaccination.
China has approved its first domestically developed mRNA vaccine against COVID-19, its manufacturer said on Wednesday, months after the relaxation of strict zero-COVID regulations sparked a surge in cases.
The vaccine, developed by CSPC Pharmaceutical Group Ltd, has been approved for “emergency use” by Beijing’s health regulator, the company said in a statement on Wednesday.
It showed high efficacy in a trial in which it was used as a booster shot for people who have been given other types of vaccines, the company added, without offering further details.
China, whose home-grown vaccines are seen as less effective than the Moderna and Pfizer-BioNTech mRNA shots, has been racing to develop vaccines using messenger RNA (mRNA) technology since early 2020.
While traditional vaccines use a weakened or inactivated germ to prepare the body for a future attack from the real virus, mRNA deploys snippets of genetic material that carry instructions showing the body’s cells how to produce a protein – in this case, the spike protein on the coronavirus that causes COVID.
The body’s immune system then triggers antibodies to fight off that spike protein, making it ready for when the real coronavirus invades.
The long-awaited approval
The long-awaited approval came as infections have fallen sharply across China since it suddenly dropped its strict “zero-COVID” curbs in December, making the sales outlook for the newly approved vaccine moderate.
But it would give China an additional option to tackle future outbreaks and a base for development against newly emerging variants, scientists said.
The news of China’s first successful mRNA vaccine did not generate much buzz in domestic social media on Wednesday, as the country has returned to normal and its borders have re-opened.
Its top leaders declared a “decisive victory” over COVID last month.
CSPC said its vaccine trials showed adverse effects were substantially lower in an elderly group compared with an adult group, boosting Chinese efforts to protect its vulnerable elderly population.
The company said its independently developed mRNA vaccine SYS6006 targets some major Omicron variants and its booster dose showed good neutralisation effect against Omicron subvariants BA.5, BF.7, BQ.1.1., XBB.1.5 and CH.1.1. in clinical trials.
In a study of 4,000 participants from December 10 to January 18 when China was experiencing a surge in infections, the vaccine showed efficacy of 85.3 percent 14 to 28 days after a booster vaccination.
CSPC did not say how many doses it plans to produce. It said the vaccine could be stored at 2 to 8 C (35.6 degrees to 46.4 degrees F) for a long time.
The firm won emergency approval for clinical trials of the mRNA shot in April last year, around the same time as CanSino, another China-based company that is testing an mRNA Omicron booster shot.