Heterologous Omicron-adapted vaccine as a secondary booster promotes neutralizing antibodies against Omicron and its sub-lineages in mice

ABSTRACT

Over one billion people have received 2–3 dosages of an inactivated COVID-19 vaccine for basic immunization. Whether a booster dose should be delivered to protect against the Omicron variant and its sub-lineages, remains controversial. Here, we tested different vaccine platforms targeting the ancestral or Omicron strain as a secondary booster of the ancestral inactivated vaccine in mice. We found that the Omicron-adapted inactivated viral vaccine promoted a neutralizing antibody response against Omicron in mice. Furthermore, heterologous immunization with COVID-19 vaccines based on different platforms remarkably elevated the levels of cross- neutralizing antibody against Omicron and its sub-lineages. Omicron-adapted vaccines based on heterologous platforms should be prioritized in future vaccination strategies to control COVID-19.

KEYWORDS:

• COVID-19
• Omicron variant
• booster vaccine
• neutralizing antibody
• heterologous vaccination

Acknowledgements

M. X. and Q. M. designed the study. J. L., F. G., and other authors performed the experiments. J. L. and Q. H. wrote the manuscript. The authors thank all vaccine donors.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Emergency Key Program of Guangzhou Laboratory [No. EKPG21-30-1].