A perspective on SARS-CoV-2 virus-like particles vaccines

Abstract

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) first appeared in Wuhan, China, in December 2019. The 2019 coronavirus disease (COVID-19) pandemic, caused by SARS-CoV-2, has spread to almost all corners of the world at an alarming rate. Vaccination is important for the prevention and control of the COVID-19 pandemic. Efforts are underway worldwide to develop an effective vaccine against COVID-19 using both traditional and innovative vaccine strategies. Compared to other vaccine platforms, SARS-CoV-2 virus-like particles （VLPs ）vaccines, as a new vaccine platform, have unique advantages: they have artificial nanostructures similar to natural SARS-CoV-2, which can stimulate good cellular and humoral immune responses in the organism; they have no viral nucleic acids, have good safety and thermal stability, and can be mass-produced and stored; their surfaces can be processed and modified, such as the adjuvant addition, etc.; they can be considered as an ideal platform for COVID-19 vaccine development. This review aims to shed light on the current knowledge and progress of VLPs vaccines against COVID-19, especially those undergoing clinical trials.

Keywords: COVID-19; SARS-CoV-2; VLPs; Vaccines.

Graphical abstract

Fig. 1

The unique advantages of VLPs vaccines compared to conventional vaccines.

Fig. 2

Induction of Intrinsic and adaptive immunological responses after immunization with SARS-CoV-2 VLPs vaccines. The administration VLPs stimulates both humoral and cell-mediated immunity. VLPs interact with pattern recognition receptors (PRRs) present on the dendritic cells (DCs), such as the toll-like receptors (TLRs). DCs then engulf the VLPs through phagocytosis. This leads to the maturation of DCs, which then secrete pro-inflammatory cytokines such as TNF-α to IL-12 and recruit more antigen-presenting cells (APCs). VLPs taken up by DCs are subsequently enzymatically cleaved into short peptides that bind to major histocompatibility complexes class I (MHC I) and class II (MHC II) and are translocated to the DCs surface. The short peptide displayed on MHC II, together with CD40 and CD80/86 then interact with T cell receptor (TCR), CD40L, and CD28 presence on the naive helper T cell (Th), respectively. This promotes the proliferation and differentiation of Th cells into type 1 (Th1) and type 2 (Th2) Th cells. Aided by Th1, naive CTL proliferates and differentiates into effector and memory CTLs, providing immediate and long-lasting cellular immunity, respectively. On other hand, aided by Th2, the naive B cell differentiates into plasma B cells which actively secrete antibodies and memory B cells which provide long-lasting humoral immunity.