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University of Iowa participating in vaccine clinical trial evaluating second COVID-19 booster shots in adults

Date: Friday, April 29, 2022

University of Iowa Health Care is participating in a new Phase 2 clinical trial evaluating various additional COVID-19 booster shots. The trial aims to understand if different booster regimens can broaden immune responses in adults who already have received a primary vaccination series and a first booster shot. The various booster regimens being tested use combinations of an original (prototype) vaccine and various variant-specific vaccines as the booster shots. The study, known as the COVID-19 Variant Immunologic Landscape (COVAIL) trial, is sponsored by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health.  UI has received funding support as an agreement under NIH contract number 75N91019D00024 to Leidos Biomedical Research in Frederick, Maryland.

The COVID-19 vaccines available in the United States so far have maintained durable protection against severe COVID-19, despite their waning protection against infection and mild illness during the omicron wave. However, the new NIAID trial is preparing for the possibility of future variants evading protection against currently available COVID-19 vaccines. 

“The SARS-CoV-2 virus continues to evolve and produce new variants, and we need to continue testing new vaccine options to ensure we have vaccines available that keep up and provide protection against these new, emerging variants,” says Patricia Winokur, MD, UI professor of internal medicine and principal investigator of the UI site for the trial. 

For the mRNA-based COVID-19 vaccines, it is possible to adjust the mRNA to target specific variants. However, predicting which variants to target remains challenging. For example, the latest omicron variant and subvariants have mutations that make them substantially different from prior SARS-CoV-2 variants.  

One of the boosters being tested in the new study targets the omicron variant. However, if a new variant emerges that more closely resembles either ancestral SARS-CoV-2 or another existing variant, such as the beta or delta variants, then an omicron-specific vaccine may not offer substantial protection. In addition, an individual’s response to booster shots may also be affected by their history of prior infection and vaccination, or both, and which type of COVID-19 vaccines they received.  

The new trial, which is being conducted at up to 24 sites, including the UI, will test new and existing booster vaccines in various combinations to see which ones provide immune responses that cover existing and emerging COVID-19 variants. 

The trial aims to enroll 600 participants 18 years and older who already have received a primary COVID-19 vaccination series and booster shot. Participants will be randomly assigned to one of six booster regimens: 

  1. One 50-microgram (mcg) injection of the mRNA-1273 (Spikevax), the original Moderna vaccine, which is already authorized in the United States as a booster shot for adults; 
  2. One 50-mcg injection consisting of mRNA-1273.351 (an investigational vaccine targeting the beta variant) and mRNA-1273.529 (an investigational vaccine targeting the omicron variant); 
  3. Two vaccinations administered two months apart: each vaccination is one 50-mcg injection containing both mRNA-1273.351 (the investigational vaccine targeting the beta variant) and mRNA-1273.529 (the investigational vaccine targeting the omicron variant); 
  4. One 50-mcg injection consisting of mRNA-1273.617d.2 (an investigational vaccine targeting the delta variant) and mRNA-1273.529 (the investigational vaccine targeting the omicron variant); 
  5. One 50-mcg injection of mRNA-1273.529 (the investigational vaccine targeting the omicron variant); and 
  6. One 50-mcg injection consisting of mRNA-1273 (Spikevax) and mRNA-1273.529 (the investigational vaccine targeting the omicron variant). 

All the study vaccines included in this first stage of the trial are manufactured by Moderna, Inc., based in Cambridge, Massachusetts. The trial will be adapted to enroll more participants to evaluate additional vaccine platforms and variant vaccines from other manufacturers as needed to further inform public health decisions. 

Participants will be monitored for symptoms and adverse events following vaccination and will be asked to return to the clinic during set times over the course of 12-14 months to provide blood samples. Investigators will evaluate the samples in the laboratory to measure and characterize immune responses to SARS-CoV-2 strains. Investigators aim to have initial findings available by August 2022. 

The study is being conducted in collaboration with academic medical centers across the U.S., NIAID’s Infectious Diseases Clinical Research Consortium and the NIAID SARS-CoV-2 Assessment of Viral Evolution (SAVE) Program. For more information about the trial, including specific site locations, and for details on how to participate, please visit clinicaltrials.gov and search for the identifier NCT05289037