A COVID-19 candidate vaccine from Novavax has produced the highest reported levels of neutralizing titers in non-human primate studies. “We are seei...
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Novavax announces high neutralizing antibody titers in COVID-19 vaccine
A COVID-19 candidate vaccine from Novavax has produced the highest reported levels of neutralizing titers in non-human primate studies.
“We are seeing neutralizing titers in the 10,000 range in non-human primates,” Gregory Glenn, president of R&D at Novavax Inc. (NASDAQ:NVAX), said Tuesday in a presentation to the BIO annual meeting.
Glenn was discussing Novavax’s NVX CoV2373, a protein antigen made using the company’s nanoparticle technology and that includes its adjuvant Matrix-M.
Glenn said he believes the immunogenicity data will translate to high levels of efficacy in humans.
The company’s vaccine candidate is being tested in a Phase I trial and at-risk manufacturing is ramping up to a capacity of 2 billion doses in 2021.
In a June 2 presentation, Novavax showed that NVX CoV2373 induced animals to produce neutralizing antibodies against SARS-CoV-2 and that titers increased at least eightfold following a second vaccination. The company also showed that Matrix-M enhances immunogenicity.
The company’s adjuvant plays an important role in boosting its potency. Novavax Chairman James Young told BioCentury in an interview last month that in a baboon study, “We got more antibodies to the spike protein and more neutralizing antibodies to the spike protein with 1 μg with Matrix-M compared to 25 μg with no adjuvant.”
On May 13 during a World Vaccine Congress webcast, Novavax presented the baboon data, which also showed that single doses of NVX-CoV2373 plus Matrix-M led to higher neutralization titers than one or two immunizations without the adjuvant. Neutralization was measured using a cytopathic effect assay.
The Novavax data, which has not been formally reported, is higher than neutralizing titer reports from three other vaccine candidates. The data are not directly comparable because the vaccines act through different mechanisms, and preclinical tests were conducted under different dosing regimens.
AstraZeneca plc (LSE:AZN; NYSE:AZN) has reported that AZD1222, a candidate viral vector vaccine it has licensed from Oxford University, led to neutralizing titers up to about 40. The non-human primates had received one immunization with 2.5x1010 viral particles.
Sinovac Biotech Ltd. (NASDAQ:SVA) has reported neutralizing titers of up to about 60 from its CoronaVac candidate. Animals had been vaccinated three times with up to 6 μg of the inactivated SARS-CoV-2 vaccine.
The China National Biotec Group (CNBG) subsidiary of China National Pharmaceutical Group Corp. (Sinopharm) has reported neutralizing titers of about 200 from its BBIBP-CorV, which is also an inactivated SARS-CoV-2 vaccine. The titers were from non-human primates twice with up to 8 μg of the candidate, but not subsequently challenged with virus. Data from the study, which also assessed protection from SARS-CoV-2 challenge, were reported Sunday in
Cell.
Novavax started a Phase I trial of NVX CoV2373 in May; in July, the company expects results and plans to start a Phase II trial, Glenn said.
The company has capacity to manufacture 100 million doses in 2020, Glenn said. Novavax has contracted with Emergent Biosolutions Inc. (NYSE:EBS) to manufacture its COVID-19 vaccine candidate. In May, Novavax acquired Praha Vaccines a.s., part of the Cyrus Poonawalla Group. The Czech facility can manufacture over 1 billion doses of Matrix M adjuvant, according to Novavax.
