Icosavax : Corporate Overview

The world needs better vaccines.

We're striving to create them.

CORPORATE OVERVIEW | JULY 2022

Forward looking statements

Statements contained in this presentation regarding matters that are not historical facts are forward-looking statements. The forward-looking statements are based on the company's current beliefs and expectations and include, but are not limited to: the company's goal to progress its preclinical and clinical programs, the timing of company milestone achievement, the company's cash balance and the company's expectations regarding the prophylactic and commercial potential of its vaccine product candidates and its platform technology. Actual results may differ from those set forth in this presentation due to the risks and uncertainties inherent in the company's business, including, without limitation: the early stage of the company's development efforts; the company's novel and unproven technology and the uncertainties associated with the development of the company's novel candidates and their potential use as part of a pan-respiratory vaccine; potential delays in the commencement, enrollment, and completion of, and receipt of data from, clinical trials and preclinical studies; the company's dependence on third parties in connection with manufacturing, research, and preclinical and clinical testing; unexpected adverse side effects or inadequate immunogenicity or efficacy of the company's product candidates that may limit their development, regulatory approval, and/or commercialization as monovalent or combination or pan- respiratory vaccines; the possibility of disappointing results in later clinical trials despite promising results in earlier preclinical research or clinical trials; the potential for challenges in the manufacturing and scale up process, including without limitation challenges that reduce drug product stability or potency; competing approaches limiting the commercial value of the company's vaccine candidates and the company's VLP platform technology; regulatory developments in the United States and other countries; the company's ability to obtain and maintain intellectual property protection for its product candidates and maintain its rights under intellectual property licenses; the company's ability to fund its operating plans with its current cash, cash equivalents, and investments; the company's ability to maintain undisrupted business operations during the COVID-19 pandemic, including with respect to clinical trials, manufacturing, and supply chain; and other risks described in the company's prior filings with the Securities and Exchange Commission (SEC), including under the heading "Risk Factors" in the company's quarterly report on Form 10-Q for the quarter ended March 31, 2022 and any subsequent filings with the SEC. You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof, and the company undertakes no obligation to update such statements to reflect events that occur or circumstances that exist after the date hereof. All forward-looking statements are qualified in their entirety by this cautionary statement, which is made under the safe harbor provisions of the Private Securities Litigation Reform Act of 1995.

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What if a SINGLE VACCINE could protect you from multiple viral respiratory infections?

AND LAST BEYOND A SINGLE SEASON

AND COVER EMERGING VARIANTS

AND LIMIT UNWANTED SIDE EFFECTS

RSV hMPV

COVID-19 Flu

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AND significantly reduce hospitalization and death?

U.S. hospitalizations and deaths per year (older adults)

RSV

Annual estimates, older adults 65+

~177,000

hospitalizations

~14,000

deaths

Economic burden:

Estimated at $1.5-3B in direct

medical costs for ages 60+

hMPV

Data support similar

morbidity and

mortality to that seen

with RSV or Flu

COVID-19		Flu
Data set: August 2020-March 2022,		2019-2020 flu season, older adults 65+
older adults 60+
~2.5 million	~171,000
hospitalizations		hospitalizations
Total deaths as of March 9, 2022,
Older adults 65+
~712,000	~12,000
deaths		deaths
Economic burden:		Economic burden:
~$28B in preventable COVID-19		~$3.2B in direct medical costs,
hospitalizations costs among		adults 65+ drove ~40% of this
unvaccinated adults (18+)^		(~$1.3B)

^ Extrapolated from six months data to an annualized figure.
CDC, RSV Trends and Surveillance; CDC Health Alert network, alert CDCHAN-00443; Sieling et al 2021, Influenza Other Respiratory Viruses; CDC COVID Data Tracker for hospitalizations and deaths; CDC Burden	4
of flu, 2019-2020 flu season; Herring et al 2022, Vaccine; Peterson-KFF Health System Tracker, Unvaccinated COVID-19 hospitalizations cost billions of dollars; Putri et al 2018, Vaccine

Especially in the MORE VULNERABLE OLDER ADULT POPULATION

WANING IMMUNITY WITH TIME

CREATES RISK FOR INFECTION AND HOSPITALIZATION

R I S K

Maternal	Infant	Older adult
immunization	immunization	immunization

PROTECTING THE WORLD'S >600 MILLION* OLDER ADULTS

CAN HELP THEM ACHIEVE THEIR FULL LIFESPAN

*Aged 65+.
Adapted from B. Graham, NIH, ResViNet 2017 presentation.	5
NIH News Releases 28 Mar 2016, World's older population grows dramatically