Trials mixing and matching COVID-19 vaccines: Data Byte
Interest in mixing different COVID-19 vaccines in prime-boost regimens is on the rise due to supply issues and safety concerns. At least 12 ongoing trials were designed to test combinations of vaccines for prime and boost shots, and at least three others include secondary boosters of different vaccines, according to BioCentury’s Clinical Trial Dashboard.
Most of the trials designed to test heterologous prime-boost regimens (shown below) are pairing vaccines already authorized for emergency use, with only two of the trials including non-authorized vaccines.
One of the two trials is testing an additional boost with mRNA-1273.351, which targets the beta SARS-CoV-2 variant (B.1.351), after two doses of Moderna COVID-19 Vaccine, the authorized vaccine from Moderna Inc. (NASDAQ:MRNA). The other is a Phase I trial pairing a new mRNA vaccine and a new viral vector vaccine from Gritstone Oncology Inc.
At least three trials are testing a second boost after a standard homologous vaccine schedule (not shown in table), all of which are adding on non-authorized vaccines.
BioCentury’s analysis included ongoing Phase I-IV trials and those without an FDA-defined phase in the ClinicalTrials.gov and ChiCTR.org.cn registries.