Efficacy, immunogenicity and safety of COVID-19 vaccines in older adults: a systematic review and meta-analysis

Li, Zejun; Liu, Shouhuan; Li, Fengming; Li, Yifeng; Li, Yilin; Pu, Peiyu; Li, Sai; He, Li; Liu, Tieqiao

doi:10.3389/fimmu.2022.965971

Cited by 24 publications

(24 citation statements)

References 107 publications

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“…Specific mRNA, viral-vector-based, and inactivated SARS-CoV-2 vaccines are being used worldwide. While efficacy of vaccines have been confirmed in adults 1 – 3 , there is a debate regarding the outcomes of vaccination in the elderly 4 , 5 . Several factors affect vaccine efficacy including age, prior antigen exposure, vaccine schedule, and vaccine dose 6 .…”

Section: Introductionmentioning

confidence: 99%

The Efficacy of SARS-CoV-2 Vaccination in the Elderly: A Systemic Review and Meta-analysis

et al. 2023

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Background Given the reduced immune response to vaccines in older populations, this study aimed to evaluate the efficacy of COVID-19 vaccinations and its impact on breakthrough infection, hospital admission, and mortality in the elderly. Methods We carried out a systemic review and meta-analysis where MEDLINE, Web of Science, EMBASE, ClinicalTrials.gov, and Cochrane Central Register for Controlled Trials were queried to identify relevant literature. We included randomized controlled trials (RCTs), non-randomized trials, prospective, observational cohort, and case–control studies assessing breakthrough infection, hospital admission, and mortality after coronavirus 2 (SARS-CoV-2) vaccination in the elderly (≥ 60 years old). Results Overall, 26 studies were included in this meta-analysis. Compared with the unvaccinated group, the vaccinated group showed a decreased risk of SARS-CoV-2 infection after 28–34 (relative risk [RR] = 0.42, 95% confidence interval [CI] 0.37–0.49) and 35–60 days (RR = 0.49, 95% CI 0.37–0.62). There was a step-wise increase in efficacy with additional doses with the two-dose group experiencing decreased risk of breakthrough infection (RR = 0.37, 95% CI 0.32–0.42), hospital admissions (RR = 0.25, 95% CI 0.14–0.45), disease severity (RR = 0.38, 95% CI 0.20–0.70), and mortality (RR = 0.21, 95% CI 0.14–0.32) compared with those receiving one or no doses. Similarly three-dose and four-dose vaccine groups also showed a decreased risk of breakthrough infection (3-dose: RR = 0.14, 95% CI 0.10–0.20; 4-dose RR = 0.46, 95% CI 0.4–0.53), hospital admissions (3-dose: RR = 0.11, 95% CI 0.07–0.17; 4-dose: RR = 0.42, 95% CI 0.32–0.55), and all-cause mortality (3-dose: RR = 0.10, 95% CI 0.02–0.48; 4-dose: RR = 0.48, 95% CI 0.28–0.84) Subgroup analysis found that protection against mortality for vaccinated vs. unvaccinated groups was similar by age (60–79 years: RR = 0.59; 95% CI, 0.47–0.74; ≥ 80 years: RR = 0.76; 95% CI, 0.59–0.98) and gender (female: RR = 0.66; 95% CI, 0.50–0.87, male: (RR = 0.58; 95% CI, 0.44–0.76), and comorbid cardiovascular disease (CVD) (RR = 0.69; 95% CI, 0.52–0.92) or diabetes (DM) (RR = 0.59; 95% CI, 0.39–0.89. Conclusions Our pooled results showed that SARS-CoV-2 vaccines administered to the elderly is effective in preventing prevent breakthrough infection, hospitalization, severity, and death. What’s more, increasing number of vaccine doses is becoming increasingly effective. Supplementary Information The online version contains supplementary material available at 10.1007/s11606-023-08254-9.

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Section: Introductionmentioning

confidence: 99%

The Efficacy of SARS-CoV-2 Vaccination in the Elderly: A Systemic Review and Meta-analysis

et al. 2023

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“…Sixteen of 67 systematic reviews identified were relevant (Supplemental Table S1) and were cross-checked for articles to be included in abstract screening and full-text assessment. One prior systematic review identified had similar objectives to the current study (11) and all studies included in this prior review were included for full-text assessment. A total of 243 studies for full-text screening were identified from this first step.…”

Section: Search Strategy and Study Selectionmentioning

confidence: 99%

“…A total of 243 studies for full-text screening were identified from this first step. The main search was then conducted in the WHO COVID-19 Research Database to identify relevant studies published since the prior similar systematic review (11) S2.…”

Section: Search Strategy and Study Selectionmentioning

confidence: 99%

“…A previous meta-analysis of 32 studies in older adults aged ≥55 years found that vaccination with either one of the 2 vaccines employing novel messenger ribonucleic acid (mRNA) technology provided the highest protection against COVID-19 compared with other vaccine types (11). The mRNA vaccines were developed and granted emergency use authorization in late 2020 to globally mitigate the spread of SARS-CoV-2: mRNA-1273 (Spikevax ® ; Moderna, Inc., Cambridge, MA, USA) (12) and BNT162b2 (Comirnaty®; Pfizer/BioNTech, New York, NY, USA/Mainz, Germany) (13).…”

Section: Introductionmentioning

confidence: 99%

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Comparative Effectiveness of mRNA-1273 and BNT162b2 COVID-19 Vaccines Among Older Adults: Systematic Literature Review and Meta-Analysis Using the GRADE Framework

Kavikondala,

Haeussler,

Wang

et al. 2023

Preprint

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BackgroundThe mRNA vaccines mRNA-1273 and BNT162b2 demonstrated high efficacy against SARS-CoV-2 infection in phase 3 clinical trials, including among older adults. To inform COVID-19 vaccine selection, this systematic literature review (SLR) and meta-analysis assessed the comparative effectiveness of mRNA-1273 versus BNT162b2 in older adults.MethodsWe systematically searched for relevant studies reporting COVID-19 outcomes with mRNA vaccines in older adults aged ≥50 years by first cross-checking relevant published SLRs. Based on the cutoff date from a previous similar SLR, we then searched the WHO COVID-19 Research Database for relevant articles published between April 9, 2022 and June 2, 2023. Outcomes of interest were SARS-CoV-2 infection, symptomatic SARS-CoV-2 infection, severe SARS-CoV-2 infection, COVID-19‒related hospitalization, and COVID-19‒related death following ≥2 vaccine doses. Random-effects meta-analysis models were used to pool risk ratios (RRs) across studies. Heterogeneity was evaluated using chi-squared testing. Evidence certainty was assessed per GRADE framework.Results24 non-randomized real-world studies reporting clinical outcomes with mRNA vaccines in individuals aged ≥50 years were included in the meta-analysis. Vaccination with mRNA-1273 was associated with significantly lower risk of SARS-CoV-2 infection (RR 0.72 [95% confidence interval (CI) 0.64‒0.80]), symptomatic SARS-CoV-2 infection (RR 0.72 [95% CI 0.62‒0.83]), severe SARS-CoV-2 infection (RR 0.67 [95% CI 0.57‒0.78]), COVID-19‒related hospitalization (RR 0.65 [95% CI 0.53‒0.79]) and COVID-19‒related death (RR 0.80 [95% CI 0.64‒0.99]) compared with BNT162b2. There was considerable heterogeneity between studies for all outcomes (I2>75%) except death (I2=0%). Multiple subgroup and sensitivity analyses excluding specific studies generally demonstrated consistent results. Certainty of evidence across outcomes was rated as low (type 3) or very low (type 4), reflecting the lack of randomized-controlled trial data.ConclusionMeta-analysis of 24 observational studies demonstrated significantly lower risk of asymptomatic, symptomatic, and severe infections; hospitalizations; and deaths with the mRNA-1273 versus BNT162b2 vaccine in older adults aged ≥50 years.SUMMARY POINTSThe COVID-19 pandemic has disproportionately affected older adults, as this population is generally more susceptible to infection and severe outcomes due to immune senescence and underlying comorbidities.The 2 available mRNA vaccines mRNA-1273 and BNT162b2 demonstrated high efficacy against SARS-CoV-2 infection in phase 3 clinical trials, including among older adults.To inform COVID-19 vaccine selection, this systematic literature review and meta-analysis assessed the comparative effectiveness of mRNA-1273 versus BNT162b2 among older adults in real-world settings.Vaccination with homologous primary or booster mRNA-1273 was associated with significantly lower risk of infection (including asymptomatic, symptomatic, and severe infections), hospitalization, and death due to COVID-19 than vaccination with BNT162b2 in older adults aged ≥50 years.

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“…Omicron variants of SARS-CoV-2 have been related to reduced severity of illness and risk of death but increased incidence of breakthrough infections [1]. Primary and boosted vaccination against SARS-CoV-2 has also significantly reduced the risk for severe disease and death associated with COVID-19 [2][3][4][5], however, SARS-CoV-2 infection remains significant morbidity and mortality issue among the highly vulnerable populations including the elderly, immunocompromised people, and those with chronic diseases [6][7][8].…”

Section: Introductionmentioning

confidence: 99%

Real-world effectiveness of molnupiravir and nirmatrelvir/ritonavir among COVID-19 community, highly vaccinated patients with high risk for severe disease: Evidence that both antivirals reduce the risk for disease progression and death

Paraskevis

Gkova

Mellou

et al. 2023

Preprint

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Besides the significant benefits of vaccination against COVID-19, the risk of severe disease and death from COVID-19 among highly vulnerable populations remains of concern. Implementation of oral antiviral treatment has shown significant benefits for outpatients with high risk for severe disease, however, their effectiveness remains to be evaluated in real-life settings and in the presence of new Omicron subvariants. We aimed to investigate the effectiveness of molnupiravir and nirmatrelvir/ritonavir using a retrospective cohort design with outcomes hospital admission and death from COVID-19, in Greece. The effectiveness of each drug was estimated through a comparison of the antiviral's recipients with an age-matched control group of non-recipients, adjusted for age, previous SARS-CoV-2 infection, vaccination status, and vaccination recency. Our analysis showed that molnupiravir significantly reduced the risk for hospitalization (OR = 0.40, p < 0.001) and death from COVID-19 (OR = 0.31, p < 0.001), with the effect being more intense among elderly patients (>=75 years old). The effectiveness was higher among those with full adherence. Nirmatrelvir/ritonavir was found also to significantly reduce the risk of hospital admission (OR = 0.31, p < 0.001) and death (OR = 0.28, p < 0.001) and, similarly to molnupiravir, effectiveness was stronger among elderly patients and those with the highest levels of adherence. Analysis of the relative effectiveness of nirmatrelvir/ritonavir versus molnupiravir suggested that nirmatrelvir/ritonavir was associated with a reduced risk for hospital admission (OR = 0.58, p < 0.001) compared to molnupiravir, adjusted for age, previous SARS-CoV-2 infection, vaccination status, and co-morbidities. Our real-world study provides evidence about the reduced risk of hospitalization and death in highly vaccinated patients with a high risk for severe disease in Greece. These findings highlight that although the hospitalization and mortality risk has been reduced mainly due to vaccination and the emergence of Omicron variants, antivirals provide significant additional benefits in highly vulnerable patients and therefore their use is documented and strongly indicated.

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Efficacy, immunogenicity and safety of COVID-19 vaccines in older adults: a systematic review and meta-analysis

Cited by 24 publications

References 107 publications

The Efficacy of SARS-CoV-2 Vaccination in the Elderly: A Systemic Review and Meta-analysis

The Efficacy of SARS-CoV-2 Vaccination in the Elderly: A Systemic Review and Meta-analysis

Comparative Effectiveness of mRNA-1273 and BNT162b2 COVID-19 Vaccines Among Older Adults: Systematic Literature Review and Meta-Analysis Using the GRADE Framework

Real-world effectiveness of molnupiravir and nirmatrelvir/ritonavir among COVID-19 community, highly vaccinated patients with high risk for severe disease: Evidence that both antivirals reduce the risk for disease progression and death

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