Vaccine Info

mRNA-1345 Respiratory Syncytial Virus (RSV) Vaccine

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Last reviewed
January 9, 2022
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mRNA-1345 Respiratory Syncytial Virus (RSV) Vaccine Description

Moderna Inc.'s mRNA-1345 Respiratory Syncytial Virus (RSV) vaccine candidate encodes for a prefusion F glycoprotein, eliciting a superior neutralizing antibody response. The mRNA-1345 vaccine is a messenger RNA (mRNA) vaccine. This mRNA is entirely made in a laboratory and instructs your body to make small pieces of proteins.

In this case, the vaccine candidate contains the mRNA code for the RSV glycoprotein F, which does not cause RSV infection but helps the body's immune system recognize and protect itself if it encounters the virus. Therefore, you cannot become infected with RSV from receiving the investigational vaccine.

The Phase 1 study of mRNA-1345 to evaluate the tolerability and reactogenicity of mRNA-1345 in younger adults, older adults, and children are ongoing. All four cohorts of younger adults (ages 18-49 years) are fully enrolled. Dosing in the older adult cohort (65-79 years) is ongoing. In this de-escalation Phase 1 study, the age range of toddlers is 12-59 months. The Company shared the first interim analysis of the Phase 1 study of mRNA-1345, through 1-month post-vaccination, of the younger adult cohorts at its annual Vaccines Day on April 14, 2021. Results showed the vaccine candidate generated a geometric mean rise in neutralizing antibodies relative to a baseline of at least 11-fold.

The FDA has granted Fast Track designation for mRNA-1345 in adults older than 60 years of age. Moreover, Moderna also intends to evaluate the potential of combinations of mRNA-1345 with its vaccines against other respiratory pathogens in children and separately in older adults.

mRNA-1345 uses the same lipid nanoparticle (LNP) as Moderna's U.S. FDA Authorized SpikeVax Covid-19 vaccine and contains optimized protein and codon sequences.

Massachusetts-based Moderna's mRNA platform builds on continuous advances in basic and applied mRNA science, delivery technology and manufacturing, and has allowed the development of therapeutics and vaccines. To learn more, visit www.modernatx.com.

mRNA-1345 Respiratory Syncytial Virus (RSV) Vaccine Indication

The mRNA-1345 Respiratory Syncytial Virus (RSV) Vaccine candidate is indicated to prevent illness from the RSV. RSV is the leading cause of respiratory illness in young children. Older adults (65+) are at high risk for severe RSV infections. A single vaccination of 50 µg, 100 µg, or 200 µg was well-tolerated in older adults through month one in a phase 1 study.

RSV is the leading cause of respiratory illness in young children. RSV is the most common cause of bronchiolitis (inflammation of the small airways in the lung) and pneumonia (infection of the lungs) in children younger than one year. According to the U.S. Centers for Disease Control and Prevention, in the USA, RSV leads each year, on average, to approximately 58,000 hospitalizations among children younger than five years old, 177,000 hospitalizations among adults 65 years and older, and 14,000 deaths among adults 65 years and older.

There is no U.S. FDA-approved vaccine for RSV as of December 1, 2021.

mRNA-1345 Respiratory Syncytial Virus (RSV) Vaccine Dosage

The interim data from a Phase 1 study in older adults ages 65-79 years showed that a single mRNA-1345 vaccination of 50 µg, 100 µg, or 200 µg boosted neutralizing antibody titers against RSV-A by approximately 14-fold and against RSV-B by about 10-fold. Data were pooled across dose levels because there was no significant difference between doses.

mRNA-1345 Respiratory Syncytial Virus (RSV) Vaccine News

November 18, 2021 - Moderna, Inc. announced the first participant had been dosed in the ConquerRSV Phase 2/3 study of mRNA-1345, the Company's Respiratory Syncytial Virus (RSV) vaccine candidate.

November 4, 2021 - Moderna announced a pivotal Phase 2/3 study of respiratory syncytial virus (RSV) vaccine candidate (mRNA-1345) in older adults expected to begin in 2021; study expected to enroll approximately 34,000 participants, subject to agreement with regulatory authorities.

August 3, 2021 - Moderna, Inc. announced that the U.S. FDA had granted Fast Track designation for mRNA-1345, its investigational single-dose mRNA vaccine against RSV in adults older than 60 years of age.

May 6, 2021 - Moderna Inc., investor presentation regarding mRNA-1345 vaccine candidate.

April 14, 2021 - Moderna shared the first interim analysis of the Phase 1 study after 1-month post-vaccination of younger adults (18-49). 'mRNA-1345 was shown to increase RSV neutralizing antibodies in seropositive younger adults. As expected, neutralizing antibodies were confirmed to be present at baseline in all participants. In addition, a single vaccination of mRNA-1345 at the 50 or 100 μg dose level boosted neutralizing antibody titers against both serotypes of RSV-A and RSV-B with no apparent dose-response. At month 1, the geometric mean fold rise in neutralizing antibody relative to baseline was at least 20.5 for RSV-A and 11.7 for RSV-B.'

mRNA-1345 Respiratory Syncytial Virus (RSV) Vaccine Clinical Trials

Clinical Trial NCT04528719: A Dose Escalation Study to Evaluate Safety, Reactogenicity, and Immunogenicity of mRNA-1345 in Healthy Adults and Children Who Are Respiratory Syncytial Virus Seropositive. Estimated Completion Date: September 30, 2023

About the ConquerRSV Phase 2/3 Trial - The purpose of this clinical trial is to assess the safety of an investigational vaccine (a vaccine not yet approved by a country's drug regulatory agency) aimed at preventing RSV infection in women and men over 60.

The study will be conducted in 2 phases: Phase 2 and Phase 3. In the Phase 2 segment, between 400 and 2,000 participants will be randomly assigned to receive a single injection of either mRNA-1345 vaccine at the selected dose or placebo in a 1:1 randomization ratio.

In the Phase 3 segment, between 32,000 and 33,600 participants will be randomly assigned to receive a single injection of either mRNA-1345 vaccine at the selected dose or placebo in a 1:1 randomization ratio.