Ipsilateral or contralateral boosting of mice with mRNA vaccines confers equivalent immunity and protection against a SARS-CoV-2 Omicron strain

• Published in: Journal of virology Vol. 98; no. 9; p. e0057424
• Main Authors: Ying, Baoling, Liang, Chieh-Yu, Desai, Pritesh, Scheaffer, Suzanne M., Elbashir, Sayda M., Edwards, Darin K., Thackray, Larissa B., Diamond, Michael S.
• Format: Journal Article
• Language: English
• Published: United States American Society for Microbiology 17.09.2024
• Subjects: 2019-nCoV Vaccine mRNA-1273 - immunology; Angiotensin-Converting Enzyme 2 - genetics; Angiotensin-Converting Enzyme 2 - immunology; Angiotensin-Converting Enzyme 2 - metabolism; Animals; Antibodies, Neutralizing - blood; Antibodies, Neutralizing - immunology; Antibodies, Viral - blood; Antibodies, Viral - immunology; B-Lymphocytes - immunology; COVID-19 - immunology; COVID-19 - prevention & control; COVID-19 - virology; COVID-19 Vaccines - administration & dosage; COVID-19 Vaccines - immunology; Editor’s Pick; Female; Humans; Immunization, Secondary; Immunoglobulin G - blood; Immunoglobulin G - immunology; Mice; mRNA Vaccines - immunology; SARS-CoV-2 - immunology; Spike Glycoprotein, Coronavirus - genetics; Spike Glycoprotein, Coronavirus - immunology; T-Lymphocytes - immunology; Vaccines and Antiviral Agents; Virology; SARS-CoV-2; infection; vaccine; immunity; B-cell responses; T cell responses
• ISSN: 0022-538X; 1098-5514; 1098-5514
• DOI: 10.1128/jvi.00574-24

Sequential boosting with mRNA vaccines has been an effective strategy to overcome waning immunity and neutralization escape by emerging SARS-CoV-2 variants. However, it remains unclear how the site of boosting relative to the primary vaccination series shapes optimal immune responses or breadth of protection against variants. In K18-hACE2 transgenic mice, we observed that intramuscular boosting with historical monovalent or variant-matched bivalent vaccines in the ipsilateral or contralateral limb elicited comparable levels of serum spike-specific antibody and antigen-specific B and T cell responses. Moreover, boosting on either side conferred equivalent protection against a SARS-CoV-2 Omicron challenge strain. Our data in mice suggest that the site of intramuscular boosting with an mRNA vaccine does not substantially impact immunity or protection against SARS-CoV-2 infection.