Revelation Biosciences, Inc., a Life Sciences Company Developing Therapeutics and Diagnostics for Respiratory Viral Infections, Including COVID-19, to Become Publicly Traded through a Merger with Petra Acquisition, Inc.

Revelation Biosciences, Inc., a Life Sciences Company Developing

Therapeutics and Diagnostics for Respiratory Viral Infections, Including COVID-19, to Become Publicly Traded through a Merger with Petra

NEW YORK, NY & SAN DIEGO, CA - August

30, 2021 - Revelation Biosciences, Inc. ("Revelation"), a clinical-stage life sciences company focused on the development

of immunologic-based therapies for the prevention and treatment of disease, and Petra Acquisition, Inc. ("Petra") (NASDAQ:

PAICU, PAIC, & PAICW), a special purpose acquisition company ("SPAC"), today announced they have entered into a

definitive merger agreement for a business combination that will result in Revelation becoming a publicly traded company.

An Urgent Need for Prevention and Treatment

of Respiratory Infections

In 2019, lower respiratory tract infections (LRTIs),

including pneumonia and bronchiolitis, affected 489 million people globally. During the 2019-2020 season, the CDC estimates that influenza

was associated with 38 million illnesses, 18 million medical visits, 405,000 hospitalizations, and 22,000 deaths.

The burden of respiratory infections on the healthcare

system and economy is significant, with respiratory infections leading to more doctor visits and absences from school and work than any

other illness. In addition, recent studies suggest a troubling increase in deaths from these viruses.

a recent study from Houston Methodist shows a rapid return of seasonal respiratory viruses after COVID-19 restrictions were relaxed in

the state of Texas. In England, positive RSV samples among suspected cases in children have increased from 1.2% to 8.9%, which is of particular

concern to local health leaders given the disease is most common during the winter months.

pandemic brought on by COVID-19, with over 4.4 million deaths globally, has only heightened the need for easy-to-use, effective therapies

that prevent the user from becoming infected, or that activate the innate immune system to combat early infections.

As respiratory infections impact populations and

economies around the world - including the global pandemic brought on by COVID-19 - Revelation is developing innate immune

system based therapeutics and diagnostics for the identification, prevention and treatment of respiratory diseases.

Revelation - Proven Leadership with Extensive

Product Development Experience Across Multiple Indications

Revelation's leadership and scientific teams

bring extensive product development experience across multiple indications, spanning all stages of drug development, including 8 FDA and

EMA approvals. The leadership team has a successful track record in multiple startups and turn-arounds including, 3 NASDAQ and 1 NYSE

Currently, Revelation has several product candidates

start a Phase 2 viral challenge study in the first quarter of 2022, as well as a Phase 1 proof of concept study, which is intended to

support the chronic nasal congestion program, in the fourth quarter of 2021.

Transaction Overview

the merger agreement, Revelation will merge with a wholly owned subsidiary of Petra, with Revelation being the surviving entity of the

merger and a wholly owned subsidiary of Petra. Petra, which currently holds approximately $73 million of cash in trust, will be renamed

to Revelation Biosciences, Inc. following the merger. The combined entity will have an estimated pro forma enterprise value of approximately

$128 million. Assuming no trust account redemptions by Petra's public stockholders, Revelation's existing stockholders will

own approximately 54% of the fully diluted shares of common stock of the combined company immediately following the closing of the business

company expects to receive approximately $73 million in gross proceeds from the trust account, assuming no redemptions by Petra's

existing public shareholders. The cash proceeds from the transaction are expected to fund the continued development of REVTx-99, Revelation's

lead therapeutic candidate. REVTx-99 is being developed to prevent or treat respiratory viral infections and chronic nasal congestion.

Proceeds from the transaction will also be used to fund the continued development of REVDx-501, a rapid point-of-care diagnostic that

can be used to detect various respiratory viral infections, regardless of virus type and without the need for specialized instrumentation.

closing of the transaction, the company will be led by existing management from Revelation, including CEO James Rolke.

The transaction has been approved by the Board

of Directors of both Petra and Revelation and is subject to the satisfaction of customary closing conditions, including the approval of

Petra's stockholders. The transaction is expected to close in the fourth quarter of 2021.

Additional information

about the proposed business combination, including a copy of the merger agreement and investor presentation, will be provided in a Current

Report on Form 8-K to be filed by Petra with the Securities and Exchange Commission (the "SEC") and available at www.sec.gov.

In addition, Petra Acquisition, Inc. intends to file a registration statement on Form S-4 with the SEC, which will include a proxy statement/prospectus,

and will file other documents regarding the proposed transaction with the SEC.

"We have all seen the crippling effects

on lives and economies when a virus takes over," said James Rolke, Chief Executive Officer of Revelation. "We believe innovations

like REVTx-99 will enable a return to normalcy, alleviating concerns about exposure to severe respiratory infections. The mechanism of

REVTx-99, which activates the innate immune system, has the potential to reduce the exposure risks associated with travel, medical care

and normal daily interactions by preventing and combating early infection. Our merger with Petra Acquisition will provide the capital

needed to further our innovations and ensure they are widely available to transform the prevention and treatment landscape of viral respiratory

diseases which lead to millions of deaths annually as well as immense healthcare and economic disruptions."

"Revelation Biosciences represents an opportunity

to dramatically reduce the impact and severity respiratory infections have on our lives," said Andreas Typaldos, CEO and Chairman

of the Board of Petra. "This transaction will provide James and the proven leadership team at Revelation the capital necessary to

continue innovating in the world of innate immune system therapeutics and diagnostics - the first step towards a healthier future."

Investor Conference Call Information

Revelation and Petra will host a joint investor

conference call and webcast to discuss the proposed transaction on August 30, 2021 at 4:30 p.m. Eastern Time. The conference call can

be accessed by dialing 877-407-0792 for domestic callers and 201-689-8263 for international callers. Please provide the operator with

the conference ID number 13722753 to join the conference call or click here for the webcast. An archive of the conference call and webcast

will be available on Revelation's website for 30 days following the call.

About Revelation Biosciences, Inc.

Revelation Biosciences, Inc. is a clinical stage

life sciences company focused on the development of immunologic-based therapies for the prevention and treatment of disease. Revelation

has several product candidates in development. REVTx-99, the lead therapeutic candidate, is an intranasal immunomodulator to prevent or

treat infections caused by various respiratory viruses such as SARS-CoV-2 including its variants, influenza A and B, parainfluenza, rhinovirus,

and RSV. REVTx-200 is an intranasal immunomodulator adjunct to be used in combination with an intramuscular vaccination for more complete

immunity. REVTx-200 is based on the same technology used in REVTx-99. In addition to Revelation's therapeutic pipeline, Revelation

is also developing REVDx-501, a rapid point-of-care diagnostic that can be used to detect any respiratory viral infection, regardless

of virus type or strain, without the need for specialized instrumentation. For more information on Revelation, please visit www.RevBiosciences.com.

About Petra Acquisition, Inc.

Petra Acquisition, Inc. (Nasdaq: PAIC) is a blank

check company organized for the purpose of effecting a merger, share exchange, asset acquisition, stock purchase, recapitalization, reorganization

or other similar business combination with one or more businesses or entities, with an initial focus on target businesses in the healthcare

or a healthcare-related industry.

Forward-Looking Statements

This press release contains

forward-looking statements as defined in the Private Securities Litigation Reform Act of 1995, as amended, including statements regarding

the anticipated benefits of the transaction, the anticipated timing of the transaction, the future business and financial condition of

the company post-closing and expected financial impacts of the transaction, the satisfaction of closing conditions to the transaction,

the level of redemptions of Petra's public stockholders; the market opportunities for Revelation's product candidates; and

the potential for regulatory approval for Revelation's product candidates. These forward-looking

statements are generally identified by the words "anticipate", "believe", "expect", "estimate",

"plan", "outlook", and "project" and other similar expressions. Forward-looking statements are statements

that are not historical facts. We caution investors that forward-looking statements are based on management's expectations and are

subject to various risks and uncertainties. As a result, caution must be exercised in relying on forward-looking statements, which speak

only as of the date they were made. The following factors, among others, could cause actual results to differ materially from those described

in these forward-looking statements: the occurrence of any event, change or other circumstances that could give rise to an amendment or

termination of the Merger Agreement and the proposed transaction contemplated thereby; the inability to complete the transactions contemplated

by the Merger Agreement due to the failure to obtain approval of the stockholders of Petra or Revelation or other conditions to closing

in the Merger Agreement; the inability to project with any certainty the amount of cash proceeds remaining in the Petra trust account

at the closing of the transaction; the uncertainty relative to the cash made available to Revelation at the closing should any material

redemption requests be made by the Petra stockholders (since the sources of cash projected in this press release assume that no redemptions