A survey of mechanisms underlying current and potential COVID‐19 vaccines

Abstract

The emergence of SARS‐CoV‐2 caught the world off guard resulting in a global health crisis. Even though COVID‐19 have caused the death of millions of people and many countries are still battling waves of infections, the odds of the pandemic ending soon have turned significantly in our favor. The key has been the development and distribution of a broad range of vaccines in record time. In this survey, we summarize the immunology required to understand the mechanisms underlying current and potential COVID‐19 vaccines. Furthermore, we provide an up to date (according to data from WHO May 27, 2022) overview of the vaccine landscape consisting of 11 approved vaccines in phase 4, and a pipeline consisting of 161 vaccine candidates in clinical development and 198 in preclinical development (World Health Organization, Draft landscape and tracker of COVID‐19 candidate vaccines [Internet], WHO, 2022). Our focus is to provide an understanding of the underlying biological mode of action of different vaccine platform designs, their advantages and disadvantages, rather than a deep dive into safety and efficacy data. We further present arguments concerning why a broad range of vaccines are needed and discuss future challenges.

Heterologous versus homologous COVID-19 booster vaccinations for adults: systematic review with meta-analysis and trial sequential analysis of randomised clinical trials

“…Additionally, we compared vaccine regimens with three doses against those with four doses to explore differences in their risk ratios. As different vaccine booster platforms use distinct mechanisms to elicit immune responses [ 18 ], which may lead to varying efficacy and safety profiles [ 19 ], we also conducted a subgroup analysis to compare differences in risk ratios between boosters with different vaccine platforms, including inactivated, protein-based, viral vectored, and mRNA-based boosters. Furthermore, we investigated the variation in risk ratios for vaccine efficacy outcomes between trials from 2023 and those from 2022, thereby allowing us to consider the potential influence of the predominance of XBB subvariants towards the end of 2022 and 2023.…”

Causes and Effects of COVID-19 Vaccine Hesitancy Among Pregnant Women and its Association with Adverse Maternal, Placental, and Perinatal Outcomes

“…Human-to-human transmission occurs through close contact, respiratory secretions, and aerosols. SARS-CoV-2 is a coronavirus that is an enveloped, positive-sense, single-stranded RNA virus containing 12 open-reading frames encoding protein, including four structural proteins: envelope, membrane, nucleocapsid, and lastly, the spike protein [47]. The molecular mechanism of host entry is through the surface spike glycoprotein (S protein).…”

Boosting the immunogenicity of the CoronaVac SARS-CoV-2 inactivated vaccine with Huoxiang Suling Shuanghua Decoction: a randomized, double-blind, placebo-controlled study

“…Vaccination proved to be a safe and effective way to reduce mortality and morbidity from COVID-19. According to the World Health Organization, there were 198 COVID-19 vaccine candidates in preclinical development, 161 COVID-19 vaccine candidates in clinical development, and 11 approved phase IV COVID-19 vaccines as of May 27, 2022 ( 1 ). The latter included 1 recombinant protein vaccine, 3 nucleic acid vaccines, 3 inactivated vaccines, and 4 vector vaccines, which have been used in different populations worldwide ( 2 ).…”