Chinese Covid-19 vaccine gets UAE nod for therapeutic use trial

Approval follows earlier green light in the UAE and New Zealand for preventive use trials of YishengBio vaccine
Patients with mild to moderate Covid-19 infections will be targeted first in trial of regimen involving two shots seven days apart

Chinese coronavirus vaccines

Zhuang Pinghuiin Beijing

Published: 12:00pm, 7 Sep 2021

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A Chinese Covid-19 vaccine that completes dosage within a week has been cleared for trial in the United Arab Emirates as both a preventive and therapeutic option.

The UAE’s approval for therapeutic use human trials of the vaccine developed by Beijing-based YishengBio came last Thursday, with efficacy studies on mild to moderate Covid-19 infections to be carried out first.

This comes after the UAE health ministry last month also approved phase 1 human trials for preventive use of the vaccine, as did the New Zealand medical regulatory authority.

The human trials will be carried out in partnership with the Pharmaceutical Development Company of UAE and New Zealand Clinical Research.

Recruitment of trial participants in New Zealand was expected to start soon, while applications for clinical trials in more countries were under way, YishengBio CEO David Shao told the South China Morning Post.

He said preclinical studies had showed that the vaccine was capable of inducing rapid and high levels of neutralising antibodies and cellular immunity.

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In a non-human primate preclinical study, monkeys were infected with coronavirus first before being injected with what Shao called the first therapeutic Covid-19 vaccine in the country, with “promising results”.

“The vaccine can induce cellular immunity. We found good results in animal studies, which is why we were also given approval for conducting relevant evaluation by the UAE health ministry,” Shao said.

The recombinant protein-based YishengBio vaccine targets the spike protein of the coronavirus and involves an independently developed adjuvant, a compound that boosts the immune response effect of vaccines. Recombinant technology involves growing the DNA coding of a coronavirus antigen, which stimulates an immune response.

The patented PIKA adjuvant was partly the reason the vaccine required an interval of just seven days between the required two doses, Shao said.

Some recombinant protein Covid-19 vaccines, such as one developed by the Anhui Zhifei Longcom, involve three doses to be taken within two months.

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“We developed the PIKA adjuvant platform more than 10 years back … It has been used in our hepatitis B vaccines as well as our rabies vaccine that is under early stage human trials, and immune-oncology products. We used Covid-19 vaccine on this platform and the result looks good, too,” Shao said.

PIKA did not involve aluminium, the oldest and most common ingredient in adjuvants, Shao said.

“Thanks to our very special adjuvant, the durability of immunity is greatly enhanced and [it is] very likely we can achieve promising results with only two doses and a one week interval. The levels of neutralising antibodies have been very high in animal studies and we are very excited about the results.”

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Shao said animal serum studies showed the YishengBio vaccine could offer broad and lasting protection against coronavirus variants including Alpha, Beta, Gamma and Lambda even at day 448 post vaccination, indicating good durability of the immune response. With just a week needed to complete the regimen, the vaccine would be potentially very useful during an outbreak.

Shao said the company hoped to explore application prospects with “rigorous clinical trials” that could test whether the vaccines could induce rapid, robust immunity response in humans, with lasting effect and broader protection from various variants as shown in animal trials.

The early and late stage trials would all be held overseas as Covid-19 is not prevalent in China, Shao said, adding that a production facility nearing completion in Shenyang, in northeast China’s Liaoning province, would be able to roll out up to 1 billion doses a year.