RT Journal Article
SR Electronic
T1 Limiting the priming dose of a SARS CoV-2 vaccine improves virus-specific immunity
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2021.03.31.437931
DO 10.1101/2021.03.31.437931
A1 Sarah Sanchez
A1 Nicole Palacio
A1 Tanushree Dangi
A1 Thomas Ciucci
A1 Pablo Penaloza-MacMaster
YR 2021
UL http://biorxiv.org/content/early/2021/04/01/2021.03.31.437931.abstract
AB Since late 2019, SARS-CoV-2 has caused a global pandemic that has infected 128 million people worldwide. Although several vaccine candidates have received emergency use authorization (EUA), there are still a limited number of vaccine doses available. To increase the number of vaccinated individuals, there are ongoing discussions about administering partial vaccine doses, but there is still a paucity of data on how vaccine fractionation affects vaccine-elicited immunity. We performed studies in mice to understand how the priming dose of a SARS CoV-2 vaccine affects long-term immunity to SARS CoV-2. We first primed C57BL/6 mice with an adenovirus-based vaccine encoding SARS CoV-2 spike protein (Ad5-SARS-2 spike), similar to that used in the CanSino and Sputnik V vaccines. This prime was administered either at a low dose (LD) of 106 PFU or at a standard dose (SD) of 109 PFU, followed by a SD boost in all mice four weeks later. As expected, the LD prime induced lower immune responses relative to the SD prime. However, the LD prime elicited immune responses that were qualitatively superior, and upon boosting, mice that were initially primed with a LD exhibited significantly more potent immune responses. Overall, these data demonstrate that limiting the priming dose of a SARS CoV-2 vaccine may confer unexpected benefits. These findings may be useful for improving vaccine availability and for rational vaccine design.Competing Interest StatementPablo Penaloza-MacMaster reports being a Task Force Advisor to the Illinois Department of Public Health (IDPH) and the Governor on SARS CoV-2 vaccine approval and implementation in the state of Illinois.Pablo Penaloza-MacMaster is a member of the COVID-19 Vaccine Regulatory Science Consortium (CoVAXCEN) at Northwestern University.