As of October 14th, a trial was done consisting of randomly selected healthy adult 18-55 years old and 65-85 years of age to receive the placebo or the RNA vaccine. "Two lipid nanoparticle–formulated, nucleoside-modified RNA vaccine candidates: BNT162b1, which encodes a secreted trimerized SARS-CoV-2 receptor–binding domain; or BNT162b2, which encodes a membrane-anchored SARS-CoV-2 full-length spike, stabilized in the prefusion conformation."

Results: Each group at 15 participants where 12 received the vaccine and 3 received the placebo. BNT162b2 resulted in lower incidence and a severity in systemic reactions.

The safety and immunogenicity data from this U.S. phase 1 trial of two vaccine candidates consisting of people of a range of ages, added to earlier interim safety and immunogenicity data regarding BNT162b1 in younger adults from trials in Germany and the United States, support the selection of BNT162b2 for advancement to a pivotal phase 2–3 safety and efficacy evaluation.

Reference (was not adding as a node so was added to here): Walsh, Edward E., et al. Safety and Immunogenicity of Two RNA-Based Covid-19 Vaccine Candidates: NEJM. 8 Oct. 2020, www.nejm.org/doi/full/10.1056/NEJMoa2027906?query=featured_coronavirus.Â