A Chinese vaccine maker has announced positive early results for its messenger RNA jab, as Covid-19 spreads rapidly across a population that has so far been inoculated with more traditional vaccines.
CanSinoBio said on Friday its vaccine had elicited 23 to 29 times more antibodies than an inactivated jab when given as a booster to people who had already received three shots.
The “phase 2b” trial of more than 400 people — which usually comes before a gold-standard phase 3 trial — showed positive results against the Omicron variants BA.1 and BA.5.
CanSinoBio’s mRNA vaccine programme and another by rival Sinopharm are among a handful in China that, if successful, could help the country as it grapples with soaring Covid-19 case rates and hospitalisations. But it could take many months until such a vaccine is approved.
A low uptake of boosters and less effective vaccines have helped the virus to spread quickly as the country abandoned its policy of strict lockdowns.
China has mainly vaccinated its population with shots from Sinopharm and Sinovac that use a killed virus to teach the immune system to react to a future infection, rather than the genetic code contained in mRNA jabs.
The two homegrown vaccines have not been as effective as the western mRNA vaccines from BioNTech/Pfizer and Moderna, particularly in tackling new variants.
China has not imported the western mRNA vaccines. Moderna refused to hand over to Beijing the core intellectual property behind its vaccine, leading to a collapse in negotiations.
BioNTech partnered with Chinese manufacturer Fosun International in 2020 to develop and commercialise its vaccine in China but it is still not available to Chinese nationals. The German government struck a deal to enable its nationals who are in China to get the jab.
CanSinoBio already has a Covid-19 vaccine available in China and recommended by the World Health Organization as a safe and effective shot. In November some Chinese cities began to roll out an inhaled version, sending its Hong Kong-listed shares up as much as 70 per cent.
In the trial of its mRNA vaccine, more than half the participants were more than 60 years old, and the older cohort tended to tolerate the mainly mild side effects better than their younger counterparts.
Seven days after vaccinations, participants’ neutralising antibodies — which tackle a virus — were 23 times higher against the BA.5 variant than those who had been given a fourth dose of the same inactivated vaccine they had previously received.
Shares in CanSinoBio rose 4 per cent to HK$71.70 on Friday.