VBI Vaccines’ pan-coronavirus vaccine disappoints in PhI study

The first data from a clinical trial of a vaccine designed to protect against many kinds of coronaviruses suggest that efforts to significantly improve over existing Covid-19 shots will be hampered by high levels of immunity that many people already have to the virus.

The results of the 101-person study conducted by VBI Vaccines were disclosed Wednesday morning in a press release. The announcement, which was light on details, said that the pan-coronavirus vaccine boosted antibodies against multiple variants of SARS-CoV-2 as well as coronaviruses that infect bats and pangolins.

David Anderson

But in an exclusive interview with Endpoints News, chief scientific officer David Anderson revealed that less than 10% of participants who got one or two high doses of the vaccine in the trial (six out of 69 people) saw their antibody levels boosted at least four times higher than before the shot — a common benchmark for vaccine developers.

“It’s a 10% that had not been so heavily vaccinated or so infected that you can actually see boosting in the response,” Anderson said.

And according to data that VBI showed Endpoints, the 34 patients who got a single high dose of the vaccine had their antibodies against the Wuhan strain of the virus rise 1.6 times on average after a month. CEO Jeff Baxter insisted that the modest boost was “clinically meaningful,” in part because the antibody levels fell only 25% after five months, a rate slower than that seen with mRNA booster shots for Covid-19.

Execs haven’t decided whether to move the vaccine into later-stage trials, although they say funding to do so is available.

VBI’s vaccine was designed early in the pandemic, long before variants of concern began emerging. It’s a virus-like particle that displays spike proteins from the coronaviruses that cause SARS, MERS and Covid-19, and the goal was to protect against emerging forms of SARS-CoV-2 or animal coronaviruses that might make the jump to humans.

Gaurav Gaiha

Gaurav Gaiha, a scientist developing his own novel coronavirus vaccines at the Ragon Institute of MGH, MIT and Harvard, told Endpoints that the results were “ambiguous” and “a little disappointing.”

Gaiha was intrigued by the possibility of a more durable immune response but wished to see more data on the vaccine’s ability to spur antibodies against animal coronaviruses or variants to which people have little preexisting immunity toward. “That would be the most compelling thing to be able to share,” he said.

VBI’s press release noted that antibody levels in the responders ranged from a 5.8-time increase for Omicron BA.5 to a 14.2-time increase for Beta — variants of SARS-CoV-2 that are long gone. The company hasn’t tested the vaccine against more recent variants but said that data on antibody protection against the SARS and MERS coronaviruses could come later this year.

Baxter said that VBI has secured committed funding through the Canadian government to take the vaccine to the next stage of testing but hasn’t decided if it will do so. “We do expect to be speaking to some of the major global pharma companies,” he added.

The company also has funding through the Coalition for Epidemic Preparedness Innovations (CEPI) to develop new versions of its nanoparticle vaccine that could add in spike proteins from more recent variants — for up to five unique antigens in one particle.

VBI’s stock $VBIV has plummeted 95% this year, bringing its market capitalization to roughly $14.4 million. In April, the Cambridge, MA-based company announced layoffs and an “increased focus” on commercializing its hepatitis B vaccine. VBI had $20.8 million in cash at the end of June and got $15 million from its partnership with Brii Bio in July.

Editor’s note: The company’s name was incorrect in the headline as has been updated.

antibodies
vaccines
pharma