Effectiveness of COVID-19 Vaccine Booster Shot Compared with Non-Booster: A Meta-Analysis

Abstract

The analysis of the effectiveness of booster shots compared with primary vaccination is extremely vital. This paper aimed to summarize the results of all available evidence studies on the effectiveness of booster vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Articles published up to 21 June 2022 were systematically searched through PubMed and EMBASE databases. The searched studies were independently assessed for quality using the Newcastle–Ottawa Scale. Results: Seven studies (nine datasets) met the criteria and were included in this study. The pooled results demonstrated a 71% (OR = 0.29, 95% CI = 0.17–0.48) reduction in SARS-CoV-2 infection rates among subjects who received a booster shot compared with those who did not receive a booster shot of coronavirus disease (COVID-19) vaccine. In addition, this analysis emphasized that during the period when the Delta variant was predominant, subjects who received the booster shot showed an 82% (OR = 0.18, 95% CI = 0.13–0.25) reduction in infection rates. Moreover, during the period of dominance of the Omicron variant, subjects who received the booster vaccination displayed a 47% (OR = 0.53, 95% CI = 0.35–0.81) reduction in infection rates. This finding confirmed that booster vaccination against the Omicron variant is significantly less effective than that against the Delta variant. In pandemic periods, correlations between the dominant variant and the efficacy of the COVID-19 vaccine booster should be considered when making vaccine booster plans.

Booster vaccination protection against SARS-CoV-2 infections in young adults during an Omicron BA.1-predominant period: A retrospective cohort study

“…The calculated booster effectiveness was 56% (95% CI: [42%, 67%]), which is slightly lower than a previously reported effectiveness against symptomatic COVID-like illness in adults (66%; 95% CI: [64%, 68%]) in the same time period [ 17 ]. Our estimate is similar to the reduction in cumulative incidence of reported infections associated with booster vaccination during an Omicron wave in Los Angeles County [ 33 ] and consistent with a pooled estimate of booster effectiveness (47%; 95% CI: [19%, 65%]) from a meta-analysis of studies completed during periods of Omicron predominance across the globe [ 34 ]. Importantly, our analysis includes both symptomatic and asymptomatic infections because the student population was under active surveillance, whereas none of the studies included in the meta-analysis examined a population under active surveillance [ 7 , 35 – 40 ].…”

Profiling Humoral Immunity After Mixing and Matching COVID-19 Vaccines Using SARS-CoV-2 Variant Protein Microarrays

“…Evasion of the Omicron strain against neutralizing antibodies is demonstrated by both in vitro studies like yeast display mutation screening and neutralization antibody assays ( 25 , 26 ). A meta-analysis of 7 studies show that during the omicron variant dominance period, the reduction of infection rates by booster shots has decreased from 82% to 47% ( 27 ). In certain studies, a heterologous schedule containing one dose each of the vaccines AZD1222 and COVID-19 (BNT162b2 or mRNA-1273) produce greater neutralizing antibody titers against SARS-CoV-2 variants and a more potent cellular response than a homologous schedule containing two doses ( 28 , 29 , 30 , 31 , 32 ).…”

In-depth genetic characterization of the SARS-CoV-2 pandemic in a two-year frame in North Macedonia using second and third generation sequencing technologies

“…A large meta-analysis showed that the effectiveness of the COVID-19 vaccines against the Delta variant was 86% (RR = 0.14, 95% CI: 0.07-0.54) (56). Moreover, boostervaccinated individuals demonstrated a significant reduction in infection rates compared with non-booster-vaccinated subjects (57). The loss of immunity caused by the poor booster vaccination coverage is a plausible reason for the breakthrough infections in North Macedonia, as it has been demonstrated that protection against the Delta variant waned over time in vaccinated persons and that an additional vaccine dose restored protection (58).…”