COVID-19 Vaccine Booster Strategies for Omicron SARS-CoV-2 Variant: Effectiveness and Future Prospects

Abstract

In the light of the lack of authorized COVID-19 vaccines adapted to the Omicron variant lineage, the administration of the first and second booster dose is recommended. It remains important to monitor the efficacy of such an approach in order to inform future preventive strategies. The present paper summarizes the research progress on the effectiveness of the first and second booster doses of COVID-19. It also discusses the potential approach in vaccination strategies that could be undertaken to maintain high levels of protection during the waves of SARS-CoV-2 infections. Although this approach can be based, with some shortcomings, on the first-generation vaccines, other vaccination strategies should be explored, including developing multiple antigen-based (multivariant-adapted) booster doses with enhanced durability of immune protection, e.g., through optimization of the half-life of generated antibodies.

A randomized phase I/II safety and immunogenicity study of the Montanide-adjuvanted SARS-CoV-2 spike protein-RBD-Fc vaccine, AKS-452

“…7 ). Note, however, additional booster administrations of mRNA- and adenovirus-based vaccines have demonstrated increased neutralization toward Omicron, suggesting that activation of B cells against mutant SP/RBD epitopes could be accomplished by multiple vaccination doses [27] , [40] , [41] . Perhaps the underlying mechanism of greater reactivity to omicron with SP/RBD-based AKS-452 or with increased SP-based vaccine dosing may be related to the “original antigenic sin” phenomenon [42] .…”

Immune Response to COVID-19 mRNA Vaccination in Previous Nonresponder Kidney Transplant Recipients After Short-term Withdrawal of Mycophenolic Acid 1 and 3 Months After an Additional Vaccine Dose

“…40 However, the extent of protection against other remaining Omicron subvariants and other future SARS-CoV-2 variants is yet unclear. 41 …”

Immunogenicity of a spike protein subunit-based COVID-19 vaccine with broad protection against various SARS-CoV-2 variants in animal studies

“…Many publications have evaluated the safety and immunogenicity elicited by homologous (same type of vaccine) or heterologous (different type of vaccines) COVID-19 vaccine booster. The heterologous prime-boost were demonstrated to be well tolerated, and the neutralizing antibody induction can be further enhanced compared to homologous prime-boost subjects [53][54][55]. For example, Atmar et al demonstrated that heterologous booster was able to induce 7-63 folds increase of neutralizing antibody, whereas homologous booster only showed 4-20 folds of increase in the study with different primary vaccination and booster combination [56].…”