Merck Receives Positive CHMP Opinion for VAXNEUVANCEtm (Pneumococcal 15-valent Conjugate Vaccine) in Individuals 18 Years of Age and Older

Merck (NYSE: MRK), known as MSD outside the United States and Canada, today announced that the European Medicines Agency's Committee for Medicinal Products for Human Use (CHMP) has recommended the approval of VAXNEUVANCEtm (Pneumococcal 15-valent Conjugate Vaccine) for active immunization for the prevention of invasive disease and pneumonia caused by Streptococcus pneumoniae in individuals 18 years of age and older.

The CHMP recommendation will now be reviewed by the European Commission for marketing authorization in the European Union, and a final decision is expected by the end of the year.

The CHMP opinion was based on data from seven randomized, double-blind clinical studies evaluating VAXNEUVANCE in 7,438 individuals from a variety of adult populations and clinical circumstances. In July 2021, VAXNEUVANCE received approval from the U.S. Food and Drug Administration (FDA) for active immunization for the prevention of invasive disease caused by Streptococcus pneumoniae serotypes 1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, 22F, 23F and 33F in adults 18 years and older.

About Pneumococcal Disease

The global prevalence of pneumococcal disease, an infection caused by bacteria called Streptococcus pneumoniae, is evolving. Highly aggressive strains, or serotypes, threaten to put more people at risk for invasive pneumococcal illnesses such as bacteremia (infection in the bloodstream); bacteremic pneumonia (pneumonia with bacteremia); and meningitis (infection of the coverings of the brain and spinal cord), as well as non-invasive pneumonia (when pneumococcal disease is confined to the lungs). While healthy adults can suffer from pneumococcal disease, patient populations particularly vulnerable to infection include older adults such as those 65 years of age and older, people with HIV, and those with certain chronic health conditions.

About VAXNEUVANCE (Pneumococcal 15-valent Conjugate Vaccine)

VAXNEUVANCE, Merck's 15-valent pneumococcal conjugate vaccine, consists of purified capsular polysaccharides from S. pneumoniae serotypes 1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, 22F, 23F and 33F individually conjugated to CRM197 carrier protein.

VAXNEUVANCE is indicated in the U.S. for active immunization of adults 18 years of age and older for the prevention of invasive disease caused by the S. pneumoniae serotypes contained in the vaccine.

U.S. Select Safety Information for VAXNEUVANCE in Adults 18 Years of Age and Older

Do not administer VAXNEUVANCE to individuals with a severe allergic reaction (e.g., anaphylaxis) to any component of VAXNEUVANCE or to diphtheria toxoid.

Some individuals with altered immunocompetence, including those receiving immunosuppressive therapy, may have a reduced immune response to VAXNEUVANCE.

The most commonly reported solicited adverse reactions in individuals 18 through 49 years of age were: injection site pain (75.8%), fatigue (34.3%), myalgia (28.8%), headache (26.5%), injection site swelling (21.7%), injection site erythema (15.1%) and arthralgia (12.7%).

The most commonly reported solicited adverse reactions in individuals 50 years of age and older were: injection site pain (66.8%), myalgia (26.9%), fatigue (21.5%), headache (18.9%), injection site swelling (15.4%), injection site erythema (10.9%) and arthralgia (7.7%).

Vaccination with VAXNEUVANCE may not protect all vaccine recipients.

Merck's Commitment to Infectious Diseases

For more than 100 years, Merck has contributed to the discovery and development of novel medicines and vaccines to combat infectious diseases. In addition to a combined portfolio of vaccines and antibacterial, antiviral and antifungal medicines, Merck has multiple programs that span discovery through late-stage development. To learn more about Merck's infectious diseases pipeline, visit www.merck.com.

About Merck

For over 130 years, Merck, known as MSD outside of the United States and Canada, has been inventing for life, bringing forward medicines and vaccines for many of the world's most challenging diseases in pursuit of our mission to save and improve lives. We demonstrate our commitment to patients and population health by increasing access to health care through far-reaching policies, programs and partnerships. Today, Merck continues to be at the forefront of research to prevent and treat diseases that threaten people and animals ? including cancer, infectious diseases such as HIV and Ebola, and emerging animal diseases ? as we aspire to be the premier research-intensive biopharmaceutical company in the world. For more information, visit www.merck.com and connect with us on Twitter, Facebook, Instagram, YouTube and LinkedIn.

Forward-Looking Statement of Merck & Co., Inc., Kenilworth, N.J., USA

This news release of Merck & Co., Inc., Kenilworth, N.J., USA (the "company") includes "forward-looking statements" within the meaning of the safe harbor provisions of the U.S. Private Securities Litigation Reform Act of 1995. These statements are based upon the current beliefs and expectations of the company's management and are subject to significant risks and uncertainties. There can be no guarantees with respect to pipeline products that the products will receive the necessary regulatory approvals or that they will prove to be commercially successful. If underlying assumptions prove inaccurate or risks or uncertainties materialize, actual results may differ materially from those set forth in the forward-looking statements.

Risks and uncertainties include but are not limited to, general industry conditions and competition; general economic factors, including interest rate and currency exchange rate fluctuations; the impact of the global outbreak of novel coronavirus disease (COVID-19); the impact of pharmaceutical industry regulation and health care legislation in the United States and internationally; global trends toward health care cost containment; technological advances, new products and patents attained by competitors; challenges inherent in new product development, including obtaining regulatory approval; the company's ability to accurately predict future market conditions; manufacturing difficulties or delays; financial instability of international economies and sovereign risk; dependence on the effectiveness of the company's patents and other protections for innovative products; and the exposure to litigation, including patent litigation, and/or regulatory actions.

The company undertakes no obligation to publicly update any forward-looking statement, whether as a result of new information, future events or otherwise. Additional factors that could cause results to differ materially from those described in the forward-looking statements can be found in the company's 2020 Annual Report on Form 10-K and the company's other filings with the Securities and Exchange Commission (SEC) available at the SEC's Internet site (www.sec.gov).

Please see U.S. Prescribing Information for VAXNEUVANCE (Pneumococcal 15-valent Conjugate Vaccine) at https://www.merck.com/product/usa/pi_circulars/v/vaxneuvance/vaxneuvance_pi.pdf and U.S. Patient Information at https://www.merck.com/product/usa/pi_circulars/v/vaxneuvance/vaxneuvance_ppi.pdf.