Tonix Pharmaceuticals Reports Positive COVID-19 Vaccine Efficacy Results in Non-Human Primates Vaccinated with TNX-1800 and Challenged with Live SARS-CoV-2 Vaccine Candidate TNX-1800 Protected Both Upper and Lower Airway

Tonix Pharmaceuticals Holding Corp. 8-K

Tonix Pharmaceuticals Reports Positive COVID-19

Vaccine Efficacy Results in Non-Human Primates Vaccinated with TNX-1800 and Challenged with Live SARS-CoV-2

Vaccine Candidate TNX-1800 Protected Both

Upper and Lower Airways After Challenge with SARS-CoV-2, Suggesting an Ability to Block Forward Transmission

TNX-1800 is Based on a Proprietary Vaccine

Platform Designed to Stimulate Long Term T cell Immunity

CHATHAM, N.J., March 17, 2021 - Tonix Pharmaceuticals Holding Corp.

(Nasdaq: TNXP) (Tonix or the Company), a clinical-stage biopharmaceutical company, today announced preliminary results following

vaccination of non-human primates with TNX-1800 (modified horsepox virus, live vaccine), a live attenuated COVID-19 vaccine candidate

engineered to express the SARS-CoV-2 (CoV-2) spike protein. Immunogenicity and protective efficacy of single-dose TNX-1800 were

assessed at two dose levels (n=4 per group). At Day 41 after the vaccination, animals were challenged with live SARS-CoV-2 through

intra-nasal and intra-tracheal routes. Protection was assessed at Day 47, six days after challenge. The research is part of an

ongoing collaboration between Southern Research, the University of Alberta and Tonix.

"We are pleased that all eight animals vaccinated with TNX-1800

had undetectable SARS-CoV-2 in their upper and lower airways 6 days after challenge with SARS-CoV-2," said Seth Lederman,

M.D., President and Chief Executive Officer of Tonix Pharmaceuticals. "Today's results are from the second phase of

a study in which TNX-1800 vaccinated and control animals were challenged with SARS-CoV-2. Last Fall, we reported that all eight

of animals vaccinated manifested takes', a skin reaction to horsepox vaccination which is a validated biomarker of

functional T cell immunity, and that vaccination was associated with neutralizing antibodies in each case. The positive results

of the protection from live CoV-2 challenge that we are reporting today validate the capacity for TNX-1800 to protect against COVID-19,

and also validate the take' after TNX-1800 vaccination as a biomarker for functional T cell immunity."

Dr. Lederman continued, " 'Take is considered

important because it is otherwise difficult and costly to measure the T cell response to a vaccine. Vaccines that elicit a strong

T cell response, like horsepox and closely related vaccinia, have been established to provide long-term, durable immunity and to

block forward transmission. Single dose horsepox and vaccinia vaccination led to the eradication of smallpox, which, like CoV-2

is transmitted by the respiratory route. In the successful campaign to eradicate smallpox, take' was used as a biomarker

for protective immunity. We believe the absence of detectable CoV-2 in the upper or lower airways shows the potential for TNX-1800

to decrease shedding of virus and is consistent with decreased transmission."

"Although many successful vaccines have been put into use around the world, much remains unknown about

COVID-19, its emerging variants, and the durability of current vaccines," Dr. Lederman continued "We designed TNX-1800

as a single dose vaccine using a vector known to provide long term T cell immunity. This was originally demonstrated by the vector's

use as the backbone of Edward Jenner's smallpox vaccine which typically provided lifetime immunity with a single dose. Moreover,

by preventing forward transmission of the smallpox virus, it became a defining force in establishing herd immunity .Like Jenner's

smallpox vaccine, TNX-1800 can be scaled up for manufacturing and will not require a costly and cumbersome cold chain for distribution

and storage. It will also be glass-sparing, with 100 doses filled per vial. These features, coupled with the results announced

today, encourage us to advance TNX-1800 to human Phase 1 trials in the second half of 2021 when we expect to have Good Manufacturing

Practice, or cGMP, quality TNX-1800 available."

The Company believes the findings also demonstrate the flexibility

of the horsepox vaccine platform and its capability to be tailored to other diseases of interest in military and civilian populations.

Key features and results:

Anthony Macaluso, Ph.D., Executive Vice President, Strategic

Development at Tonix said, "In addition to their impact on the development

of a COVID-19 vaccine, these data also demonstrate the utility of horsepox as a vaccine platform that can be used to address many

other diseases of interest to the military and the general public. The horsepox platform has the following attributes favorable

for vaccine development: strong induction of both B and T cell immunity; amenability to genetic modification; and the ability to

express multiple genes, either alone or in combination. In addition, the horsepox vaccine platform allows for rapid scalability

of manufacturing, which is a key advantage of the horsepox virus over other platforms such as non-replicating viruses, DNA/RNA,

or protein subunit vaccines."

TNX-1800 is a live modified horsepox virus vaccine for percutaneous

administration that is designed to express the Spike protein of the SARS-CoV-2 virus and to elicit a predominant T cell response.

Horsepox and vaccinia are closely related orthopoxviruses that are believed to share a common ancestor. Tonix's TNX-1800

vaccine candidate is administered percutaneously using a two-pronged, or "bifurcated" needle. TNX-1800 is based on

a horsepox vector, which is a live replicating, attenuated virus that elicits a strong immune response. The major cutaneous reaction

or "take" to vaccinia vaccine was described by Dr. Edward Jenner in 1796 and has been used since then as a biomarker

for protective immunity to smallpox, including in the World Health Organization's accelerated smallpox eradication program

that successfully eradicated smallpox in the 1960's. The "take" is a measure of functional T cell immunity validated

by the eradication of smallpox, a respiratory-transmitted disease caused by variola. Tonix's proprietary horsepox vector

is believed to be more closely related to Jenner's vaccinia vaccine than modern vaccinia vaccines, which appear to have evolved

by deletions and mutations to a phenotype of larger plaque size in tissue culture and greater virulence in mice. Live replicating

orthopoxviruses, like vaccinia or horsepox, can be engineered to express foreign genes and have been explored as platforms for

vaccine development because they possess; (1) large packaging capacity for exogenous DNA inserts, (2) precise virus-specific control

of exogenous gene insert expression, (3) lack of persistence or genomic integration in the host, (4) strong immunogenicity as a

vaccine, (5) ability to rapidly generate vector/insert constructs, (6) readily manufacturable at scale, and (7) ability to provide

direct antigen presentation. Relative to vaccinia, horsepox has substantially decreased virulence in mice1. Horsepox-based

vaccines are designed to be single dose, vial-sparing vaccines that can be manufactured using conventional cell culture systems,

with the potential for mass scale production and packaging in multi-dose vials.

1Noyce RS, et al. (2018) PLoS One. 13(1):e0188453

Founded in 1941, Southern Research (SR) is an independent,

501(c)(3) nonprofit, scientific research organization with more than 400 scientists and engineers working across three divisions:

Drug Discovery, Drug Development, and Engineering. SR has supported the pharmaceutical, biotechnology, defense, aerospace, environmental,

and energy industries. SR works on behalf of the National Institutes of Health, the U.S. Department of Defense, the U.S. Department

of Energy, NASA and other major aerospace firms, utility companies, and other external academic, industry and government agencies.

SR pursues entrepreneurial and collaborative initiatives to develop and maintain a pipeline of intellectual property and innovative

technologies that positively impact real-world problems. SR has numerous ongoing drug discovery programs, which encompass drug

discovery programs to combat various forms of cancer, Alzheimer's, schizophrenia, opioid use disorder, human immunodeficiency

virus, disease, Parkinson's, tuberculosis, influenza, and others. SR's strong history, which includes over 75 years

of successful collaborations to solve complex problems, has led to the discovery of seven FDA-approved cancer drugs-a number

rivaling any other U.S. research institute. Furthermore, experts at SR are well-equipped to assist with the challenging landscapes

of drug design and development technologies and market viability. SR is headquartered in Birmingham, Alabama with additional laboratories

and offices in Frederick, Maryland.

about SR can be found at https://southernresearch.org/

About Tonix Pharmaceuticals Holding Corp.

Tonix is a clinical-stage biopharmaceutical

company focused on discovering, licensing, acquiring and developing small molecules and biologics to treat and prevent human disease

and alleviate suffering. Tonix's portfolio is primarily composed of central nervous system (CNS) and immunology product candidates.

The CNS portfolio includes both small molecules and biologics to treat pain, neurologic, psychiatric and addiction conditions.

Tonix's lead CNS candidate, TNX-102 SL1, is in mid-Phase 3 development for the management of fibromyalgia, and

positive data on the RELIEF Phase 3 trial were recently reported. The Company expects interim data from a second Phase 3 study,

RALLY, in the third quarter of 20212 and topline data in the fourth quarter of 2021. The immunology portfolio includes

vaccines to prevent infectious diseases and biologics to address immunosuppression, cancer, and autoimmune diseases. Tonix's

lead vaccine candidate, TNX-18003, is a live replicating vaccine based on the horsepox viral vector platform to protect

against COVID-19, primarily by eliciting a T cell response. Tonix reported positive efficacy data from animal studies of TNX-1800

in the first quarter of 2021. TNX-8013, live horsepox virus vaccine for percutaneous administration, is in development

to protect against smallpox and monkeypox.

1TNX-102 SL is an investigational

new drug and has not been approved for any indication.

2Pending submission and agreement

from FDA on statistical analysis plan.

3TNX-1800 and TNX-801 are investigational