What Phylex BioSciences does

Phylex BioSciences, Inc. is a privately held, preclinical-stage vaccine developer founded in 2020 and headquartered in Del Mar, California, operating with a 1-10 person team. The company builds AI-derived mRNA nanoparticle vaccines against zoonotic viruses, using deep learning (including AlphaFold2) to design antigens that are encoded by mRNA to self-assemble into nanoparticles displaying 60 copies of the optimized antigen. Its pipeline spans second-generation SARS-CoV-2, Nipah, West Nile, SFTS, human metapneumovirus, Andes hantavirus, and Chikungunya vaccine candidates, with peer-reviewed immunogenicity and protection data published in Frontiers in Immunology (2022) and Vaccine (2025) and collaborations with the US CDC, Pasteur Institute, University of Bern, ATUM, and Geneva University Hospitals.

The company is led by co-founder and CEO Pascal Brandys (genomics pioneer and inventor of mRNA nanoparticle vaccines, previously co-founder of Genset acquired by Merck-Serono at ~$1.5B) and co-founder and Chief Scientific Adviser Jens Herold, Ph.D. (coronavirus specialist since 1990 and senior manager at Boehringer Ingelheim). Phylex outsources manufacturing and trial execution to contract research organizations and technology partners, and has demonstrated a two-working-day ready-to-manufacture vaccine design for Andes hantavirus and 32-fold higher SARS-CoV-2 delta neutralization titers versus current mRNA vaccines in published preclinical studies.

Phylex is pre-revenue with no commercial customers or approved products; its stated path to monetization is licensing, co-development partnerships with pharmaceutical companies, and eventual product sales, with plans to initiate clinical trials on a compassionate basis in exposed populations. No institutional investors, parent companies, subsidiaries, or external funding rounds are disclosed in the available data, suggesting the company is currently founder-financed and reliant on academic and government research partnerships for validation and progression.

Name

Phylex BioSciences

Legal name

Phylex BioSciences, Inc.

Website

https://phylexbio.com

Company type

Private

Founded year

2020

Operating status

Operating

Headcount range

1–10 employees

Short description

Phylex BioSciences is a preclinical, founder-owned vaccine developer using AI-derived mRNA nanoparticle technology to design vaccine candidates against zoonotic viruses including SARS-CoV-2, Nipah, West Nile, SFTS, hMPV, Andes hantavirus, and Chikungunya for global public-health and pharmaceutical partners.

Ownership category

akta.pro rank

Product category

mRNA Vaccines

NAICS

Biological Product (except Diagnostic) Manufacturing (325414)

SIC

Biological Products, (No Disgnostic Substances) (2836)

akta.pro primary industry

Vaccine Technology Platforms (mRNA, viral vector, protein subunit, inactivated/live-attenuated, VLP, DNA) (HLAAAEAD)

akta.pro secondary industry

mRNA Therapeutics (vaccines, protein replacement, immuno-oncology) (HLAAADAA)

Keywords

• MRNA nanoparticle vaccines
• AI antigen design
• Zoonotic virus vaccines
• Vaccine research development
• Biologics platform

Headquarters

HQ city

Del Mar

HQ country

United States

HQ region

North America

Offices1 record

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

Technology or R&D, Personnel, Operations, Supply Chain, Marketing or Sales

Revenue model

1. Vaccine Development and Licensing: Phylex BioSciences is a pre-revenue vaccine development company focused on developing AI-derived mRNA nanoparticle vaccines against zoonotic viruses. The company is pursuing clinical development with plans to initiate clinical trials with exposed individuals on a compassionate basis. Revenue would likely come from licensing agreements, co-development partnerships with pharmaceutical companies, or eventual product sales.

Go-to-market motion1 record

Marketing channels7 records

Core offering

Phylex BioSciences develops AI-derived mRNA nanoparticle vaccines against zoonotic viruses using deep learning for antigen design. Its mRNA directly encodes self-assembling nanoparticles that display 60 copies of an optimized antigen, mimicking the virus in size, geometry, and symmetry to elicit long-lasting neutralizing antibody immunity. The pipeline includes vaccine candidates for SARS-CoV-2, Nipah virus, West Nile virus, SFTS virus, human metapneumovirus, Andes hantavirus, and Chikungunya virus.

Product overview

Phylex BioSciences is developing the first AI-derived mRNA nanoparticle vaccines with advanced deep learning AI models. The company's core platform is an mRNA nanoparticle technology that encodes for self-assembling nanoparticles displaying 60 copies of optimized antigens, providing enhanced immunogenicity and long-lasting immunity. The product portfolio includes vaccine candidates against SARS-CoV-2 (second-generation/complement vaccine), Nipah virus (first mRNA nanoparticle vaccine), West Nile virus, Severe Fever with Thrombocytopenia Syndrome virus, human metapneumovirus, Andes hantavirus, and Chikungunya virus. The platform leverages AI for accelerated antigen design and is designed to counter immune imprinting issues affecting current mRNA vaccines.

Differentiator

Problem solved

Functional benefit

Products and services

• SARS-CoV-2 Vaccine (Second-Generation) AI-derived mRNA nanoparticle vaccine designed to complement current COVID-19 vaccines by eliciting different classes of neutralizing antibodies and countering immune imprinting. Displays 60 copies of antigen based on receptor binding domain of latest SARS-CoV-2 variants. Developed for public health authorities and global health partners.
• Nipah Virus Vaccine First mRNA nanoparticle vaccine against Nipah virus causing encephalitis and respiratory distress with up to 75% fatality rate. Displays 60 copies of the head domain of the G attachment protein. Targeted at public health authorities in South Asia (Bangladesh, India) and global outbreak response partners.
• West Nile Virus Vaccine AI-derived mRNA nanoparticle vaccine in development targeting West Nile virus as an emerging threat in North America. Nanoparticle design provides enhanced protection against viral dissemination and neurological symptoms. Targeted at North American public health agencies.
• Severe Fever with Thrombocytopenia Syndrome Virus Vaccine AI-derived mRNA nanoparticle vaccine in development targeting SFTS virus as an emerging threat in Japan. Self-assembling nanoparticle platform directly applicable to zoonotic viruses. Targeted at Japanese and broader Asia-Pacific public health agencies.
• Human Metapneumovirus Vaccine AI-derived mRNA nanoparticle vaccine targeting respiratory virus spreading throughout Northern California with symptoms similar to influenza, particularly affecting young children and older adults. Targeted at U.S. public health authorities addressing seasonal respiratory outbreaks.
• Andes Hantavirus Vaccine AI-derived mRNA nanoparticle vaccine designed in two days against Andes hantavirus causing hantavirus pulmonary syndrome with up to 50% fatality rate. Person-to-person transmission documented in Argentina and Chile. Targeted at LATAM public health agencies.
• Chikungunya Virus Vaccine mRNA nanoparticle vaccine in development against Chikungunya virus, with antigen displayed on a self-assembling nanoparticle that enhances immune response including long-term adaptive cell-mediated immunity. Targeted at regions with recurring Chikungunya outbreaks.

Quantifiable outcome

• Nanoparticle displays 60 copies of optimized antigen
• +5 more outcomes

Segments4 records

Ideal customer profiles3 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

AI capability2 records

Feature5 records

Partnerships

Five partnerships are on record, tiered minor and core.

• Geneva University HospitalsminorStrategic or Co-development Partner · 13 May 2026Received the first viral sequence of the Andes hantavirus from the outbreak aboard cruise ship MV Hondius posted by Geneva University Hospitals, enabling rapid vaccine design in two working days.
• US Centers for Disease Control and Prevention (CDC)coreStrategic or Co-development Partner · 23 July 2025Collaboration with scientists of the U.S. CDC in Atlanta, Georgia on Nipah virus mRNA nanoparticle vaccine. Published results in the journal Vaccine demonstrating robust neutralizing antibody response with titers 3-fold higher than survivors of Nipah infection and 60-fold higher antibody concentration compared to most advanced mRNA Nipah vaccine in clinical trials.
• Pasteur Institute (Paris, France)coreStrategic or Co-development Partner · 23 March 2022Collaboration with the Pasteur Institute in Paris and Institute of Virology and Immunology, University of Bern, Switzerland on immunogenicity and protection studies of the mRNA nanoparticle vaccine against SARS-CoV-2 delta variant. Published proof-of-principle results demonstrating robust neutralizing antibody response with titers an order of magnitude above currently approved mRNA vaccines and protective immunity in transgenic mouse model.
• Institute of Virology and Immunology, University of BerncoreStrategic or Co-development Partner · 23 March 2022Collaboration on immunogenicity and protection studies of the mRNA nanoparticle vaccine against SARS-CoV-2 delta variant alongside the Pasteur Institute, demonstrating protective immunity in transgenic mouse model.
• ATUMcoreTechnology or Integration · 15 June 2020Collaboration leveraging ATUM's Leap-In Transposase platform to develop the cell line essential for manufacturing Phylex's universal SARS coronavirus vaccine candidate. ATUM's platform enables robust cell line development program for vaccine manufacturing, supporting GMP-compliant manufacturing and clinical development timeline acceleration.

Scale indicators6 records

Recent moves6 records

Expansion highlights4 records

Direct peers

• Moderna: Moderna is the leading mRNA vaccine company, with approved COVID-19 vaccines and a broad mRNA platform spanning infectious disease, oncology, and rare diseases. It is the most direct comparability peer to Phylex for mRNA technology, target indications (SARS-CoV-2, Nipah), and AI-augmented design, but at vastly larger scale.
• CureVac: CureVac is a pure-play mRNA technology company developing prophylactic vaccines, cancer vaccines, and molecular therapies. Its comparable focus on mRNA-encoded antigens and infectious-disease targets makes it a like-for-like small/mid-cap peer for Phylex's mRNA-nanoparticle vaccine platform.
• BioNTech: BioNTech co-developed Comirnaty with Pfizer and is the other anchor mRNA platform globally, with pipelines spanning infectious-disease vaccines, oncology, and emerging AI capabilities (InstaDeep). It competes head-on with Phylex for SARS-CoV-2 second-generation booster positioning and infectious-disease mRNA partnerships.
• Translate Bio (Sanofi): Translate Bio developed an mRNA platform and lipid-nanoparticle delivery technology for vaccines and therapeutics, acquired by Sanofi in 2022. Its mRNA + LNP encapsulation approach is materially comparable to Phylex's mRNA + nanoparticle architecture for infectious-disease applications.
• Arcturus Therapeutics: Arcturus is an mRNA medicines company with a self-amplifying RNA (STARR) platform and vaccines for COVID-19 and influenza. Its mRNA-based vaccine pipeline and self-amplifying/structured-particle orientation closely mirror Phylex's mRNA nanoparticle strategy in infectious disease.

Broad incumbents

• Pfizer: Pfizer co-developed Comirnaty with BioNTech and runs a broad vaccine portfolio including respiratory and infectious-disease programs. It is the largest counterparty for any partnership discussion Phylex could pursue and competes in the same SARS-CoV-2 booster and zoonotic vaccine spaces.
• Novavax: Novavax is a vaccine specialist with an approved protein-nanoparticle COVID vaccine and pipeline in Nipah, RSV, and malaria. Its nanoparticle vaccine technology (Matrix-M, recombinant protein nanoparticles) and active Nipah program make it especially comparable to Phylex's mRNA nanoparticle + zoonotic portfolio.
• Sanofi Pasteur: Sanofi operates one of the world's largest vaccine businesses (Sanofi Pasteur) and, through the Translate Bio acquisition, has built an mRNA vaccine franchise. It overlaps with Phylex in infectious-disease mRNA targets but at vastly broader portfolio scale and global manufacturing footprint.
• GSK (GlaxoSmithKline): GSK is a top-3 global vaccine manufacturer with established programs in influenza, meningitis, and emerging infectious diseases. Its broad vaccine portfolio and adjuvant systems (AS01) overlap with Phylex's target indications, especially for government tenders and stockpiling partnerships.

Emerging players

• Emergex Vaccines: Emergex is a clinical-stage company developing T-cell-targeted vaccines against pandemic-threat viruses including Nipah, Ebola, and Lassa. It is comparable as a small-cap, emerging-market vaccine specialist focused on high-fatality zoonotic diseases overlapping Phylex's pipeline.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat4 records

Key risks6 records

Key highlights7 records

Customer concentration

Revenue estimate

Valuation estimate

Number of profiles

Profiles2 records

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Phylex BioSciences