Study Details

Protocol Status:
Study Purpose:
Study Design:

This is a multicenter, randomized, double-blind, placebo-controlled, Phase 3, pivotal efficacy and safety study in adults >=18 to <60 years of age and >=60 years of age. The efficacy, safety, and immunogenicity of Ad26.COV2.S will be evaluated in participants living in, or going to, locations with high risk for acquisition of SARS-CoV-2 infection after administration of study vaccine.

The study will consist of a screening phase of up to 28 days, a 52-week double-blind study period (including the administration of 1 dose of study vaccine [on Day 1], after randomization), and a long-term follow-up period of 1 additional year. The duration of individual participation, including screening, will be maximum 2 years and 1 month. If a participant is unable to complete the study, but has not withdrawn consent, an early exit visit will be conducted. The end-of-study is considered as the completion of the last visit for the last participant in the study.

Participants will be randomized in parallel in a 1:1 ratio to receive intramuscular (IM) injections of Ad26.COV2.S or placebo as shown in Table 2. Ad26.COV2.S will be administered at a dose level of 1×10^11 vp.

Study Population:
Study Size:

60000

Study Duration:
Treatment Regimen:
Primary Objectives:

To demonstrate the efficacy of Ad26.COV2.S in the prevention of molecularly confirmed, moderate to severe/critical COVID-19, as compared to placebo, in SARS-CoV-2 seronegative adults

Secondary Objectives:

Efficacy:

1. To demonstrate the efficacy of Ad26.COV2.S in the prevention of molecularly confirmed,
moderate to severe/critical COVID-19, as compared to placebo, in adults regardless of
their serostatus

2. To evaluate the efficacy of Ad26.COV2.S in the prevention of molecularly confirmed,
moderate to severe/critical COVID-19 in SARS-CoV-2 seronegative adults, as compared to
placebo, with onset 1 day after study vaccination

3. To assess the effect of Ad26.COV2.S on COVID-19 requiring medical intervention (based
on objective criteria) compared to placebo

4. To assess the effect of Ad26.COV2.S on SARS-CoV-2 viral RNA load compared to
placebo for moderate to severe/critical COVID-19

5. To assess the effect of Ad26.COV2.S on molecularly confirmed, mild COVID-19

6. To assess the effect of Ad26.COV2.S on COVID-19 as defined by the US FDA harmonized
case definition

7. To assess the effect of Ad26.COV2.S on all molecularly confirmed symptomatic COVID-
19, as compared to placebo

8. To assess the effect of Ad26.COV2.S on occurrence of asymptomatic or undetected
infections with SARS-CoV-2, as compared to placebo

Safety:

1. To evaluate safety in terms of SAEs (during the entire study), MAAEs (until 6 months
post-vaccination), and MAAEs leading to study discontinuation (during the entire study)
for all participants

2. In a subset of participants, to evaluate the safety and reactogenicity in terms of solicited
local and systemic AEs during 7 days after vaccination, and in terms of unsolicited AEs
during 28 days post-vaccination

Immunogenicity:

1. In a subset of participants, to evaluate the immunogenicity of Ad26.COV2.S, as compared to placebo

Key Study Personnel

Personnel list available upon request.

Study Sites List