# Implementing Vaccine and Treatment Evaluation Unit (VTEU) Clinical Site: DMID 21-0012 Mix and Match

> **NIH NIH UM1** · UNIVERSITY OF MARYLAND BALTIMORE · 2021 · $1,121,472

## Abstract

Summary/Abstract
The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), causative agent of the coronavirus
disease of 2019 (COVID-19) which was designated as a pandemic respiratory illness (WHO - 2020), has
infected over 172 million people worldwide and resulted in over 3.7 million deaths, including > 596,000 in the
United States (June 3, 2021, WHO; www.who.int). Multiple Phase 3 efficacy trials of SARS-CoV-2 vaccine
constructs are underway or in long-term follow-up in the U.S, and these studies have supported 3 Emergency
Use Authorizations (EUAs) for COVID vaccines. However, logistical and manufacturing obstacles are limiting
the number of vaccines available at any one time. Further, the emergence of variant strains has raised
concerns about the breadth of immunity and protection achieved by the current vaccines. WHO SAGE and
CDC ACIP have identified the safety and immunogenicity of mixed schedules as a critical and immediate
research priority to inform policy on the use of mixed schedules.
Knowledge of the safety, tolerability, and immunogenicity of a delayed boost vaccine incorporating a
heterologous platform or variant spike lineage administered following EUA prime dosing regimens may
greatly stretch the ability to immunize against SARS-CoV-2 at a population level, induce immunity to variant
circulating strains and improve upon the breadth and durability of protection. The heterologous boost strategy
will also provide an opportunity to thoroughly evaluate innate, cellular, and humoral immune responses
elicited from the multiple prime boost combinations using very similar immunogens, utilizing mRNA,
adenovirus- vectored, and protein- based platforms. As new immunogens are manufactured to closely match
emerging variants, these foundational data will be key to the evaluation of future variant and heterologous
prime- boost strategies. This phase 1/2 clinical trial will evaluate the safety and immunogenicity of different
heterologous delayed doses (boosts) in those who received an EUA vaccine (either prior to participation in
this trial, or as part of this trial).

## Key facts

- **NIH application ID:** 10424839
- **Project number:** 3UM1AI148689-02S7
- **Recipient organization:** UNIVERSITY OF MARYLAND BALTIMORE
- **Principal Investigator:** Karen L. Kotloff
- **Activity code:** UM1 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $1,121,472
- **Award type:** 3
- **Project period:** 2021-08-10 → 2025-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10424839

## Citation

> US National Institutes of Health, RePORTER application 10424839, Implementing Vaccine and Treatment Evaluation Unit (VTEU) Clinical Site: DMID 21-0012 Mix and Match (3UM1AI148689-02S7). Retrieved via AI Analytics 2026-07-19 from https://api.ai-analytics.org/grant/nih/10424839. Licensed CC0.

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