Only 16 spots left

~16 spots leftby Apr 2026

Chimpanzee Adenovirus and Self-Amplifying mRNA Prime-Boost Prophylactic Vaccines Against SARS-CoV-2 in Healthy Adults

Recruiting in Palo Alto (17 mi)

+7 other locations

Age: 18+

Sex: Any

Travel: May Be Covered

Time Reimbursement: Varies

Trial Phase: Phase 1

Waitlist Available

Sponsor: National Institute of Allergy and Infectious Diseases (NIAID)

No Placebo Group

Trial Summary

What is the purpose of this trial?

This trial is testing new COVID-19 vaccines on healthy adults to see if they are safe and effective. It includes people who have never been vaccinated and those who have already received a COVID-19 vaccine. The vaccines work by helping the immune system recognize and fight the virus.

Research Team

Eligibility Criteria

Inclusion Criteria

You are 18 years or older, and you are either a man or a non-pregnant woman.

Plan to remain living in the area for the duration of the study

Women of childbearing potential must have a negative urine or serum pregnancy test within 24 hours prior to each study vaccination

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Exclusion Criteria

You have had a severe allergic reaction in the past, such as anaphylaxis, which could include a reaction to a vaccine.

You had surgery, immobility, chronic infection, or head trauma in the last 3 months that could increase the risk of blood clots.

You have already received an approved or experimental COVID-19 vaccine, or any other vaccine that could affect the trial's results.

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Treatment Details

Interventions

ChAdV68-S (Virus Therapy)
ChAdV68-S-TCE (Virus Therapy)
SAM-LNP-S (Virus Therapy)
SAM-LNP-S-TCE (Virus Therapy)

Participant Groups

15Treatment groups

Experimental Treatment

Group I: Stage 2 (SAM-S-TCE Boosts after approved/licensed mRNA COVID-19 Vaccines) Group 9Experimental Treatment2 Interventions

3 mcg of SAM-S-TCE administered through 0.25 mL intramuscular injection in the deltoid muscle on Day 1 in participants older than 60 years of age. N=8

Group II: Stage 2 (SAM-S-TCE Boosts after approved/licensed mRNA COVID-19 Vaccines) Group 12A,BExperimental Treatment2 Interventions

10 mcg of SAM-S-TCE administered through 0.5 mL intramuscular injection in the deltoid muscle on Day 1 and 10 mcg SAM-S-TCE administered through 0.5 mL intramuscular injection in the deltoid muscle on Day 57 in participants older than 60 years of age. N=8-12

Group III: Stage 2 (SAM-S-TCE Boosts after approved/licensed mRNA COVID-19 Vaccines) Group 11A,BExperimental Treatment2 Interventions

10 mcg of SAM-S-TCE administered through 0.5 mL intramuscular injection in the deltoid muscle on Day 1 in participants older than 60 years of age. N=8-12

Group IV: Stage 2 (SAM-S-TCE Boosts after approved/licensed mRNA COVID-19 Vaccines) Group 10A,BExperimental Treatment2 Interventions

6 mcg of SAM-S-TCE administered through 0.25 mL intramuscular injection in the deltoid muscle on Day 1 in participants older than 60 years of age. N=8-12

Group V: Stage 2 (SAM-S-TCE Boosts after EUA/licensed mRNA COVID-19 Vaccines) Group 8A,BExperimental Treatment2 Interventions

10 mcg of SAM-S-TCE administered through 0.5 mL intramuscular injection in the deltoid muscle on Day 1 and 10 mcg of SAM-S-TCE administered through 0.5 mL intramuscular injection in the deltoid muscle on Day 57 in participants from 18 to 60 years of age. N=8-12

Group VI: Stage 2 (SAM-S-TCE Boosts after EUA/licensed mRNA COVID-19 Vaccines) Group 7A,BExperimental Treatment2 Interventions

10 mcg of SAM-S-TCE administered through 0.5 mL intramuscular injection in the deltoid muscle on Day 1 in participants from 18 to 60 years of age. N=8-12

Group VII: Stage 2 (SAM-S-TCE Boosts after EUA/licensed mRNA COVID-19 Vaccines) Group 6Experimental Treatment2 Interventions

6 mcg of SAM-S-TCE administered through 0.25 mL intramuscular injection in the deltoid muscle on Day 1 in participants from 18 to 60 years of age. N=10

Group VIII: Stage 2 (SAM-S-TCE Boosts after EUA/licensed mRNA COVID-19 Vaccines) Group 5Experimental Treatment2 Interventions

3 mcg of SAM-S-TCE administered through 0.25 mL intramuscular injection in the deltoid muscle on Day 1 in participants from 18 to 60 years of age. N=10

Group IX: Stage 2 (ChAd-S-TCE Boosts after approved/licensed mRNA COVID-19 Vaccines) Group 15Experimental Treatment2 Interventions

5 x 10\^11 viral particles of ChAdV68-S-TCE administered through 1.0 mL intramuscular injection in the deltoid muscle on Day 1 in participants older than 60 years of age. N=7-10

Group X: Stage 2 (ChAd-S-TCE Boosts after approved/licensed mRNA COVID-19 Vaccines) Group 14Experimental Treatment2 Interventions

1 x 10\^11 viral particles of ChAdV68-S-TCE administered through 0.5 mL intramuscular injection in the deltoid muscle on Day 1 in participants older than 60 years of age. N=7-10

Group XI: Stage 2 (ChAd-S-TCE Boosts after approved/licensed mRNA COVID-19 Vaccines) Group 13Experimental Treatment2 Interventions

5 x 10\^10 viral particles of ChAdV68-S-TCE administered through 0.5 mL intramuscular injection in the deltoid muscle on Day 1 and on or after Day 113 in participants older than 60 years of age. N=7-10

Group XII: Stage 1 (Naïve) Group 4Experimental Treatment2 Interventions

10 mcg of SAM-S-TCE administered through 0.5 mL intramuscular injection in the deltoid muscle on Day 1 and 3 mcg of SAM-S-TCE administered through 0.25 mL intramuscular injection in the deltoid muscle on or after Day 85 and no later than Day 130 in participants from 18 to 60 years of age. N=3

Group XIII: Stage 1 (Naïve) Group 3BExperimental Treatment2 Interventions

30 mcg SAM-LNP-S administered through 0.5 mL intramuscular injection in the deltoid muscle on Day 1 and 3 mcg of SAM-LNP-S administered through 0.25 mL intramuscular injection in the deltoid muscle on or after Day 85 and no later than Day 130 in participants from 18 to 60 years of age. N=7

Group XIV: Stage 1 (Naïve) Group 3AExperimental Treatment2 Interventions

30 mcg of SAM-LNP-S administered through 0.5 mL intramuscular injection in the deltoid muscle on Day 1 and 30 mcg of SAM-LNP-S administered through 0.5 mL intramuscular injection in the deltoid muscle on Day 29 in participants from 18 to 60 years of age. N=3

Group XV: Stage 1 (Naïve) Group 1Experimental Treatment3 Interventions

5 x 10\^10 viral particles of ChAdV68-S administered through 0.5 mL intramuscular injection in the deltoid muscle on Day 1 and 30 mcg of SAM-LNP-S administered through 0.5 mL intramuscular injection in the deltoid muscle on Day 29 in participants from 18 to 60 years of age. N=4