Durability of Vaccine-Induced and Natural Immunity Against COVID-19: A Narrative Review

Abstract

Vaccines developed against SARS-CoV-2 have proven to be highly effective in preventing symptomatic infection. Similarly, prior infection with SARS-CoV-2 has been shown to provide substantial protection against reinfection. However, it has become apparent that the protection provided to an individual after either vaccination or infection wanes over time. Waning protection is driven by both waning immunity over time since vaccination or initial infection, and the evolution of new variants of SARS-CoV-2. Both antibody and T/B-cells levels have been investigated as potential correlates of protection post-vaccination or post-infection. The activity of antibodies and T/B-cells provide some potential insight into the underlying causes of waning protection. This review seeks to summarise what is currently known about the waning of protection provided by both vaccination and/or prior infection, as well as the current information on the respective antibody and T/B-cell responses.

COVID-19, post-acute COVID-19 syndrome (PACS, “long COVID”) and post-COVID-19 vaccination syndrome (PCVS, “post-COVIDvac-syndrome”): Similarities and differences

“…While a recent mathematical modelling study estimated that the global COVID-19 vaccination campaign prevented 14.4 million deaths from COVID-19 in 185 countries and territories [30] (but see also a critical evaluation of the methodology of this study [31] ), the efficacy of the available COVID-19 vaccines is declining as novel SARS-CoV-2 variants emerge [32] , [33] . The current use of a bivalent booster for the two available mRNA COVID-19 vaccines (including the wild-type (Wuhan-Hu-1) and Omicron (BA.1) SARS-CoV-2 spike messenger RNAs) “likely only represents a temporizing measure until variants emerge”, and the “need to repeatedly vaccinate at-risk populations, combined with the documented emergence of a new dominant SARS-CoV-2 variant approximately every 3 to 4 months, presents a public health dilemma.” [34] .…”

Baricitinib treatment for hospitalized patients with severe COVID-19 on invasive mechanical ventilation：a propensity score-matched and retrospective analysis

“…So far, age and comorbidities such as diabetes, COPD, chronic kidney disease, have been reported to be independent predictors of mortality for COVID-19 patients (3,(18)(19)(20)(21)(22)(23). Vaccine has been shown to bring survival bene t in COVID-19, which can also in uence the outcomes (24,25). With the expanding coverage of COVID-19 vaccination, its in uence on reducing mortality could not been overlooked.…”

Clinical and Preclinical Methods of Heat-Stabilization of Human Vaccines

“…These vaccines are considered very safe because they cannot replicate in the host. Also they benefit from being able to be produced in a highly scalable manner, but there are challenges associated with short-term protection, higher production cost compared to subunit vaccines, storage requirements at low temperatures, and carrier-related immune responses (e.g., antipolyethylene glycol [PEG], antilipid). − …”