• Vaccine Name: Moderna COVID-19 vaccine
• Target Pathogen: SARS-CoV-2
• Target Disease: COVID-19
• Product Name: mRNA-1273
• Manufacturer: Moderna
• Vaccine Ontology ID: VO_0005157
• CDC CVX code: 207
• CDC CVX description: SARS-COV-2 (COVID-19) vaccine, mRNA, spike protein, LNP, preservative free, 100 mcg/0.5mL dose
• Type: mRNA vaccine
• Status: Licensed
• Host Species for Licensed Use: Human
• Antigen: S-2P antigen, made of the SARS-CoV-2 glycoprotein with a transmembrane anchor and intact S1-S2 cleavage site (Wang et al., 2020).
• Immunization Route: Intramuscular injection (i.m.)
• Description: A SARS-CoV2 RNA vaccine made of lipid nanoparticle with mRNA which encodes the S-2P antigen, made of the SARS-CoV-2 glycoprotein with a transmembrane anchor and intact S1-S2 cleavage site (Wang et al., 2020).

Macaque Response

• Vaccination Protocol: Animals were vaccinated intramuscularly at week 0 and at week 4 with either 10 or 100 μg of mRNA-1273 in 1 ml of 1× phosphate-buffered saline (PBS) into the right hind leg. (Corbett et al., 2020)
• Immune Response: The mRNA-1273 vaccine candidate induced antibody levels exceeding those in human convalescent-phase serum, with live-virus reciprocal 50% inhibitory dilution (ID50) geometric mean titers of 501 in the 10-μg dose group and 3481 in the 100-μg dose group. Vaccination induced type 1 helper T-cell (Th1)–biased CD4 T-cell responses and low or undetectable Th2 or CD8 T-cell responses. (Corbett et al., 2020)
• Challenge Protocol: At week 8 (4 weeks after the second vaccination), all animals were challenged with a total dose of 7.6×105 plaque-forming units (PFU). The stock of 1.9×105 PFU per milliliter SARS-CoV-2 (USA-WA1/2020 strain) was administered in a volume of 3 ml by the intratracheal route and in a volume of 1 ml by the intranasal route (0.5 ml per nostril). (Corbett et al., 2020)
• Efficacy: Viral replication was not detectable in BAL fluid by day 2 after challenge in seven of eight animals in both vaccinated groups. No viral replication was detectable in the nose of any of the eight animals in the 100-μg dose group by day 2 after challenge, and limited inflammation or detectable viral genome or antigen was noted in lungs of animals in either vaccine group. (Corbett et al., 2020)

Human Response

• Vaccination Protocol: All the participants were assigned sequentially to receive two doses of either 25 μg or 100 μg of vaccine administered 28 days apart. (Anderson et al., 2020) The mRNA-1273 vaccine was administered as a 0.5-ml intramuscular injection into the deltoid on days 1 and 29 of the study.
• Immune Response: By day 57, among the participants who received the 25-μg dose, the anti–S-2P geometric mean titer (GMT) was 323,945 among those between the ages of 56 and 70 years and 1,128,391 among those who were 71 years of age or older; among the participants who received the 100-μg dose, the GMT in the two age subgroups was 1,183,066 and 3,638,522, respectively. After the second immunization, serum neutralizing activity was detected in all the participants by multiple methods. Binding- and neutralizing-antibody responses appeared to be similar to those previously reported among vaccine recipients between the ages of 18 and 55 years and were above the median of a panel of controls who had donated convalescent serum. The vaccine elicited a strong CD4 cytokine response involving type 1 helper T cells. (Anderson et al., 2020)
• Side Effects: Solicited adverse events were predominantly mild or moderate in severity and most frequently included fatigue, chills, headache, myalgia, and pain at the injection site. Such adverse events were dose-dependent and were more common after the second immunization. (Anderson et al., 2020)