Israel's COVID vaccine works against Delta variant - new data

EXCLUSIVE: Israel’s BriLife vaccine, a vector-based vaccine rather than a mRNA vaccine, is effective against certain Coronavirus variants.

Photo of Prof. Zeev Rotstein, head of Hadassah-University Medical Center, being screened for eligibility to be vaccinated on Monday as part of the Phase II trial of the Israeli vaccine candidate Brilife. December 20, 2020 (photo credit: HADASSAH)
Photo of Prof. Zeev Rotstein, head of Hadassah-University Medical Center, being screened for eligibility to be vaccinated on Monday as part of the Phase II trial of the Israeli vaccine candidate Brilife. December 20, 2020
(photo credit: HADASSAH)

New research conducted by the Israel Institute of Biological Research has shown that the Israeli Brilife vaccine is effective against the Delta variant, The Jerusalem Post has confirmed.

Specifically, neutralizing antibody tests performed in the IIBR lab showed that the vaccine’s antibodies maintain their neutralization capacity against all four major viral strains: Alpha, Beta, Gamma and Delta.

The data has been submitted for peer review by a major scientific journal. The Institute said it could not discuss the data until the report had been accepted for publication.

NeuroRx CEO Dr. Jonathan Javitt confirmed that he had seen the data. He said that he was given permission by IIBR to discuss it.

In July, the Defense Ministry announced that it had signed an agreement with NRx on behalf of IIBR to help fast-track Israel’s BriLife vaccine. The US company, which is traded on Nasdaq, was given exclusive worldwide development, manufacturing and marketing rights.

According to Javitt, the lab had access to the blood serum of vaccinated patients who were found to have developed antibodies. In the lab, the researchers were able to check if these samples had the same antibodies against the Delta variant and they found that they did.

The effectiveness of the mRNA vaccines that have been largely administered in Israel to date were found to wane after about four to six months and to have been less potent against the highly infectious Delta variant. Israel embarked on a third-shot campaign that slowed infection once again, managing to stay open even as the variant circulated throughout Israel.

So far, more than four million Israelis have been vaccinated with a third shot. There is not yet new research as to how long the booster will work, but health officials expect anywhere between six months and one year.

The Brilife vaccine, in contrast, is a vector-based vaccine. It takes the vesicular stomatitis virus (VSV) and genetically engineers it so that it will express the spike protein of the novel coronavirus on its envelope.

Once injected, it does not cause a disease by itself. VSV does not harm humans; instead, the body recognizes the spike protein that is expressed on the envelope and begins to develop an immunological response. The vaccine will initially be delivered by traditional injection.

 A BRILIFE COVID-19 vaccination at Jerusalem’s Hadassah-University Medical Center during trials last year. (credit: OLIVIER FITOUSSI/FLASH90) A BRILIFE COVID-19 vaccination at Jerusalem’s Hadassah-University Medical Center during trials last year. (credit: OLIVIER FITOUSSI/FLASH90)

“The BriLife vaccine differs from other COVID-19 vaccines by presenting the entire COVID-19 spike protein to the body’s immune system,” NRx explained in a release in August. “It also differs from other COVID-19 vaccine approaches in that it is a self-propagating, live-virus vaccine in which the spike protein of the vaccine appears to evolve in a manner consistent with the evolution of the SARS-CoV-2 virus in nature.

“Thus, while variants may arise that support manual enrichment of the vaccine against those specific variants, the vaccine itself may continue to evolve in a manner that provides ongoing protection against variants,” the release said.

Javitt said there is reason to be “optimistic” that the Brilife vaccine has the potential to be both durable in terms of its protection against new variants as they arrive and long-lived in terms of the immunity it confers.

Israel has already completed the dosing of participants in a Brilife Phase II clinical trial. About 450 people received a high dose or a top dose of the vaccine, which appears to be optimal and effective. The rest of the roughly 900 participants received doses that were too low and were recommended to get a Pfizer vaccine.

The Jerusalem Post also learned on Sunday that preliminary snapshot data taken about a month ago from this Phase II trial that was taking place at Sheba Medical Center, Hadassah-University Medical Center and other hospitals around the country had thus far shown astounding results: Only five out of around 250 patients who could be evaluated at that time had contracted the virus - four of them had received a placebo.

When asked about the data, Prof. Yossi Caraco, director of the clinical research unit at Hadassah-University Medical Center who helped lead the study for Israel, said that such data needed to be looked at with precaution as it was not only too early to report but did not reflect the main goals of the trial: safety and immunological response.

“This is partial data and premature and we need to be very careful,” Caraco stressed. “The sample was at a certain time and since then there has been more data.”

But he added that “it still looks very good.”

He said that the data is expected to be fully reviewed and released sometime next month.

NRx was planning on launching a Phase II placebo study in Georgia, but that study had to be shifted to a Phase II/III registration study, meaning one that will not compare the Brilife vaccine to a placebo but against an already licensed vaccine. This is called a non-inferiority study.

The study has already benefited from input from the World Health Organization and the European Medicines Agency.  The company is waiting to launch after December 2, when a meeting of the independent safety monitoring committee of the Health Ministry is meant to review the data of Israel’s Phase II trial and confirm that the vaccine has a good safety determination.

Javitt said that Israel will also take part in this registration study.

“There is a meaningful population of adults in Israel who have refused to get mRNA vaccines and many of those people have called our study sites and volunteered to be part of the study,” he said.