New COVID-19 Vaccine from China 79% Effective Against the Delta Variant

China carried out a new Covid-19 vaccine by Clover Biopharmaceuticals that was said to combat the disease with up to 79% efficacy, and 67% for severe infections caused by any strain.

The SCB-2019 vaccine, a protein-based vaccine candidate, was also 92% effective against the Gamma variant and 59% effective against the Mu variant, according to study. Overall, these three strains comprised "73% of all strains identified in the study," it said.

(Photo : Photo by Michael Ciaglo/Getty Images)
THORNTON, CO - MARCH 06: Prepared doses of the Johnson & Johnson COVID-19 vaccine, the newest vaccine approved by the U.S. FDA for emergency use, sit in a box at an event put on by the Thornton Fire Department on March 6, 2021 in Thornton, Colorado. 

"We are pleased that SCB-2019 has successfully demonstrated efficacy against the globally dominant Delta strain and other concerning variants," Clover's chief executive officer Joshua Liang said in the statement.

"It is the first vaccine candidate to demonstrate significant efficacy against all three of these variants. Differences in vaccine efficacy across variant strains are driven by the unique mutation profiles of each variant, which can make some strains more transmissible and/or virulent than others and may enable immune escape," said Clover company.

Development of the new vaccine

The Clover company, which distributed about 414 million doses of its coronavirus vaccines around the globe, received a funding of $328m from the Coalition for Epidemic Preparedness Innovations (CEPI) for the development of the new vaccine, which also backed the AstraZeneca and Moderna Covid vaccines.

Clover announced that its new COVID-19 vaccine was found to have higher neutralizing antibodies with Th1-biased cell-mediated immune responses during Phase I of clinical trial. It also achieved primary efficacy endpoint and secondary efficacy endpoints in SPECTRA, a global pivotal Phase 2/3 clinical trial. The trial was carried out between 28 April and 10 August 2021.

Over 30,000 adults from 31 sites in the Philippines, Brazil, Columbia, South Africa and Belgium were enrolled for its clinical trial, receiving randomized doses of SCB-2019 or a placebo in a two-dose regimen, administered 21 days apart.

Of the 207 symptomatic Covid-19 cases reported at least two weeks after the second dose, participants in the trial had not contracted the coronavirus infection earlier. 52 were from a vaccinated group, while the remaining 155 formed the placebo group.

Findings show neither cases of Covid hospitalization, nor cases of severe disease in the vaccine group. "Vaccine efficacy was successfully demonstrated in an environment where 100% of SARS-CoV-2 strains observed in the efficacy analysis were variants," scientists wrote.

Also read: California Now Has the Lowest Coronavirus Transmission Rate in the U.S.

Designed to protecting those most at risk

According to study, SCB-2019 is considered the "first COVID-19 vaccine to demonstrate significantly reduced risk of COVID-19 disease in previously infected individuals."

In addition, "this vaccine is poised to play a significant role in protecting those most at risk from COVID-19, wherever they are in the world," said Dr. Richard Hatchett, CEO of CEPI.

In cases of moderate-to-severe coronavirus infections against any strain, efficacy was up to 83.7%. Unfortunately, three have died from the placebo group.

Clover said that the elder participants they recruited in the trial were limited for inoculation campaign for vaccinating the elderly population. All five cases of Covid in 65 years or older occurred in the placebo or non-vaccine group.

Also read: Delirium: Scary Long-Term Effect in Patients With Severe COVID-19 Emerges