Duration of immunity following full vaccination against SARS-CoV-2: a systematic review

Abstract

Background As vaccine roll-out continues across the globe as part of the efforts to protect humanity against SARS-CoV-2, concerns are increasingly shifting to the duration of vaccine-induced immunity. Responses to these concerns are critical in determining if, when, and who will need booster doses following full vaccination against SARS-CoV-2. However, synthesised studies about the durability of vaccine-induced immunity against SARS-CoV-2 are scarce. This systematic review synthesised available global evidence on the duration of immunity following full vaccination against SARS-CoV-2. Methods We searched through Psych Info, Web of Science, Scopus, Google Scholar, PubMed, and WHO COVID-19 databases for relevant studies published before December 2021. Five eligibility criteria were used in scrutinising studies for inclusion. The quality of the included studies was assessed based on Joana Briggs Institute’s (JBI) Critical Appraisal tool and Cochrane’s Risk of Bias tool—version 2 (RoB 2), while the reporting of the results was guided by the Synthesis Without Meta-analysis (SWiM) guidelines. Results Twenty-seven out of the 666 identified studies met the inclusion criteria. The findings showed that vaccine-induced protection against SARS-CoV-2 infections builds rapidly after the first dose of vaccines and peaks within 4 to 42 days after the second dose, before waning begins in subsequent months, typically from 3 to 24 weeks. Vaccine-induced antibody response levels varied across different demographic and population characteristics and were higher in people who reported no underlying health conditions compared to those with immunosuppressed conditions. Conclusions Waning of immunity against SARS-CoV-2 begins as early as the first month after full vaccination and this decline continues till the sixth month when the level of immunity may not be able to provide adequate protection against SARS-CoV-2. While the evidence synthesised in this review could effectively inform and shape vaccine policies regarding the administration of booster doses, more evidence, especially clinical trials, are still needed to ascertain, with greater precision, the exact duration of immunity offered by different vaccine types, across diverse population characteristics, and in different vulnerability parameters. Registration The protocol for this review was pre-registered with the International Prospective Register of Systematic Reviews [PROSPERO] (Registration ID: CRD420212818).

Heterologous boosting of neutralizing activity against Delta and Omicron SARS-CoV-2 variants in CoronaVac-primed adults; a randomized study with SCB-2019 vaccine

“…A major limitation of our study is that it only reports the immediate immune response following booster vaccination. As previously noted, immunity begins to wane within one month of completion of a primary series [5,6]. A small study of boosting of mRNA-vaccine primed adults with adenovirus-vector vaccine suggests that heterologous boosting provides an initially higher and then more durable immune response in terms of maintained levels of antibody titers [21].…”

“…These new variants accumulate mutations in the primary antigenic target, the spike protein (S-protein), so that they evade immune protection induced by vaccines developed against the ancestral Wuhan-Hu-1 strain [2][3][4]. Decreases in vaccine-induced immunity due to the natural waning of antibody titers from the first month post-vaccination [5] and this lower susceptibility of the new variants to vaccine-induced immunity has led to the observation of lower protective efficacy from the first licensed COVID-19 vaccines [6,7]. This has driven the implementation of booster vaccination campaigns, especially with vaccines heterologous to the primary series in an effort to broaden the immune response and consequently the protection against new variants [8][9][10][11][12][13].…”

Immune profile of healthcare professionals six months after vaccination or exposure to SARS‐CoV‐2 in Angola

“…The second dose begins to taper off in subsequent months, typically 3–24 weeks. Vaccine‐induced antibody response levels varied across different demographic and population characteristics and were higher in people who reported no underlying health conditions compared with those with underlying health conditions, such as immunosuppressed 7 …”

“…11 These antibodies have been detected in blood samples from infected individuals from the first few weeks after infection or when they present any symptoms related to the infection. 7 However, the duration of immunity after exposure to SARS‐CoV‐2 is still poorly understood and requires further investigation, mainly in resource‐limited countries. 8 , 9 Numerous types of COVID‐19 vaccines, including AstraZeneca, Jonhson & Johnson, and Sputinik, were administered to the Angolan population during the year 2021.…”

Associations of neuralgic amyotrophy with COVID‐19 vaccination: Disproportionality analysis using the World Health Organization pharmacovigilance database

“…The time interval between vaccination and NA coincides with the well‐known point at which the immune response is maximized after infection or vaccination and suggests a possible association between NA and COVID‐19 vaccination. 17 , 18 …”