Evan J. Anderson, MD Associate Professor of Medicine and Pediatrics Emory University School of Medicine

SARS-CoV-2 mRNA-1273 Vaccine: Encouraging Safety and Immunogenicity Data in Older Adults

MedicalResearch.com Interview with:

Evan J. Anderson, MD Associate Professor of Medicine and Pediatrics Emory University School of Medicine

Dr. Anderson

Evan J. Anderson, MD
Associate Professor of Medicine and Pediatrics
Emory University School of Medicine

MedicalResearch.com: What is the background for this study?

Response: Older adults have suffered a disproportionate number of the hospitalizations and deaths due to COVID-19. A vaccine is clearly needed for older adults.  For a number of vaccines, the immune response and efficacy of vaccines decreases with increasing age. A prime example would be influenza and the need for high dose influenza vaccine in the elderly. We had previously conducted a Phase I study in 18 – 55 year old adults of mRNA-1273 vaccine – published in NEJM 2020 with Lisa Jackson as the lead author. This phase I study was expanded to include older adults in 2 separate cohorts (56 – 70, >70 years of age) and 2 different doses.

MedicalResearch.com: What are the main findings? 

Response: No safety issues were identified in these 40 adults, but the size of study was small. The reactogenicity of the vaccine was similar to that of younger adults. We saw more local and systemic reactions after the second dose than after the first, but these were mostly mild to moderate in severity.  The most common local symptom was pain at the injection site. The most common systemic reactogenicity side effects were fatigue, chills, headache, and myalgia.  The antibody responses observed after vaccination were similar to the young adults in the Phase I study of 18 – 55 year olds.  These typically exceeded the antibody responses of most convalescent plasma samples.  Neutralizing antibodies developed within 1-2 weeks after the second dose of vaccine.  These antibody responses were better in those that had received 100 mcg in comparison to the 25 microgram dose.  T cell responses were observed were TH1 biased, which is the type of response that is thought to be of benefit.

MedicalResearch.com: What should readers take away from your report?

Response: These data from this study are very encouraging that 100 micrograms of the mRNA-1273 vaccine is tolerated in older adults and that immune responses are similar to those of younger adults.  These data support the continued evaluation of the 100 microgram dose level and 2 dose regimen in a large Phase 3 study with a more diverse study population to assess the safety and efficacy of this vaccine.

MedicalResearch.com: What recommendations do you have for future research as a result of this work?

Response: The Phase 3 study of mRNA-1273 assessing the 100 microgram dose includes older adults and will hopefully help to answer whether the vaccine works in adults of all ages.

Disclosures: E.J.A has received personal fees from AbbVie, Pfizer, and Sanofi Pasteur for consulting, and his institution receives funds to conduct clinical research unrelated to this manuscript from MedImmune, Regeneron, PaxVax, Pfizer, GSK, Merck, Novavax, Sanofi-Pasteur, Janssen, and Micron. He also serves on a safety monitoring board for Kentucky BioProcessing, Inc.


Anderson et al. Safety and immunogenicity of SARS-CoV-2 mRNA-1273 vaccine in older adults. New England Journal of Medicine DOI: 10.1056/NEJMoa2028436 (2020).



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Last Updated on October 4, 2020 by Marie Benz MD FAAD