COVID-19 vaccine development: milestones, lessons and prospects

Abstract

With the constantly mutating of SARS-CoV-2 and the emergence of Variants of Concern (VOC), the implementation of vaccination is critically important. Existing SARS-CoV-2 vaccines mainly include inactivated, live attenuated, viral vector, protein subunit, RNA, DNA, and virus-like particle (VLP) vaccines. Viral vector vaccines, protein subunit vaccines, and mRNA vaccines may induce additional cellular or humoral immune regulations, including Th cell responses and germinal center responses, and form relevant memory cells, greatly improving their efficiency. However, some viral vector or mRNA vaccines may be associated with complications like thrombocytopenia and myocarditis, raising concerns about the safety of these COVID-19 vaccines. Here, we systemically assess the safety and efficacy of COVID-19 vaccines, including the possible complications and different effects on pregnant women, the elderly, people with immune diseases and acquired immunodeficiency syndrome (AIDS), transplant recipients, and cancer patients. Based on the current analysis, governments and relevant agencies are recommended to continue to advance the vaccine immunization process. Simultaneously, special attention should be paid to the health status of the vaccines, timely treatment of complications, vaccine development, and ensuring the lives and health of patients. In addition, available measures such as mix-and-match vaccination, developing new vaccines like nanoparticle vaccines, and optimizing immune adjuvant to improve vaccine safety and efficacy could be considered.

A nanoparticle-based COVID-19 vaccine candidate elicits broad neutralizing antibodies and protects against SARS-CoV-2 infection

“…They will play an important role to better control the COVID-19 pandemic considering the shortage of SARS-CoV-2 vaccines 2. , 17. .…”

Immunogenicity of a third dose of inactivated COVID-19 vaccine in people living with HIV-1, HBV, and tuberculosis during the Omicron variant epidemic: A cross-sectional study

“…Recent Syed's study reported that the effectiveness of one dose of the COVID-19 mRNA vaccine peaked at month 1 after immunization (77% for BNT162b2 and 88.2% for mRNA-1273), following this, a decline was observed at month 2 (67.6% for BNT162b2 and 84.5% for mRNA-1273) 1 . However, the effectiveness of two doses of BNT162b2 could be 94% 2 .…”

“…Recent real-world studies performed the investigation of the sustainability of immune memory stimulated by the COVID-19 vaccines in healthcare individuals 2 , 3 , 4 . It has been known that the immunogenicity of the COVID-19 mRNA vaccine was higher than the inactivated vaccine in normal and immunocompromised patients 2 , 5 , 6 .…”

“…Recent real-world studies performed the investigation of the sustainability of immune memory stimulated by the COVID-19 vaccines in healthcare individuals 2 , 3 , 4 . It has been known that the immunogenicity of the COVID-19 mRNA vaccine was higher than the inactivated vaccine in normal and immunocompromised patients 2 , 5 , 6 . One previous study revealed that the antibodies (Abs) of two doses of inactivated vaccine immunization peaked at ∼1 month in cirrhosis people and significantly declined between month 3 and 6 7 .…”

“…Vaccinated individuals received the third dose of inactivated COVID-19 vaccine, NAbs are important indicators used in evaluating the protective immunity after vaccine injection. NAbs that block the interaction between spike proteins and their receptor angiotensin-converting enzyme 2 (ACE2) are particularly important for preventing the onset of COVID-19 during the SARS-CoV-2 wild-type (wt) or variant strain prevalence 2 . Nevertheless, the effectiveness of the third dose of inactivated COVID-19 vaccine-induced NAbs in people living with HIV-1, HBV, and tuberculosis has not been evaluated like the normal population.…”