CoChat
Sign Up
Cited by 511SARS-CoV-2 and COVID-19 ResearchImmune responses and vaccinationsVaccine Coverage and Hesitancy

Age-dependent Immune Response to the Biontech/Pfizer BNT162b2 Coronavirus Disease 2019 Vaccination

Open access
Müller, Lisa, Andrée, Marcel, Moskorz, Wiebke, Drexler, Ingo, Walotka, Lara, Grothmann, Ramona, Ptok, Johannes, Hillebrandt, Jonas +11 more·2021·Clinical Infectious Diseases
DOI 10.1093/cid/ciab381PMC PMC8135422

Published version of a preprint

Open this paper in CoChat — free accountOpen PDF

Abstract

Background: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has led to the development of various vaccines. Real-life data on immune responses elicited in the most vulnerable group of vaccinees older than age 80 years old are still underrepresented despite the prioritization of the elderly in vaccination campaigns. Methods: We conducted a cohort study with 2 age groups, young vaccinees below the age of 60 years and elderly vaccinees over the age of 80 years, to compare their antibody responses to the first and second dose of the BNT162b2 coronavirus disease 2019 vaccination. Results: Although the majority of participants in both groups produced specific immunoglobulin G antibody titers against SARS-CoV-2 spike protein, titers were significantly lower in elderly participants. Although the increment of antibody levels after the second immunization was higher in elderly participants, the absolute mean titer of this group remained lower than the <60 years of age group. After the second vaccination, 31.3% of the elderly had no detectable neutralizing antibodies in contrast to the younger group, in which only 2.2% had no detectable neutralizing antibodies. Conclusions: Our data showed differences between the antibody responses raised after the first and second BNT162b2 vaccination, in particular lower frequencies of neutralizing antibodies in the elderly group. This suggests that this population needs to be closely monitored and may require earlier revaccination and/or an increased vaccine dose to ensure stronger long-lasting immunity and protection against infection.

AI snapshot

Written from the paper’s full text.

TL;DR

In a real-life cohort of younger (<60 years) and elderly (>80 years) recipients of the BNT162b2 vaccine, spike-specific IgG and neutralizing antibody responses were substantially lower in the elderly after both doses. Nearly one-third of elderly vaccinees had no detectable neutralizing antibodies after the second dose, suggesting this group may need closer monitoring or modified vaccination strategies.

Key findings

  • After the first dose, mean spike S1 IgG was 313.3 BAU/mL in younger vaccinees versus 41.2 BAU/mL in elderly vaccinees (P < .0001); 65.9% of elderly participants were below the cutoff compared with 4.4% of younger participants.
  • After the second dose, mean IgG rose to 3702.0 BAU/mL in younger participants and 1332.0 BAU/mL in elderly participants (P < .0001); 10.6% of elderly participants remained below the cutoff, while no younger participant did.
  • Neutralizing antibodies after the first dose were present in 16.1% of younger vaccinees and only 1.2% of elderly vaccinees. After the second dose, 97.8% of younger vaccinees had neutralizing antibodies versus 68.7% of elderly vaccinees; 31.3% of elderly participants had none, compared with 2.2% of younger participants.
  • Postvaccination reactions were more common in younger participants (51.6% reported none after dose one and 25.8% after dose two) than in elderly participants (93.9% and 83.1% reported none, respectively), but reaction severity did not correlate with antibody response.

Methods

  • Prospective cohort study at a nursing home in Cologne, Germany, comparing volunteers aged <60 years and >80 years who received the BNT162b2 vaccine on the same schedule. Blood was collected 17–19 days after the first dose and 17 days after the second dose; 179 volunteers consented, and 3 with nucleocapsid antibodies were excluded, leaving 176 analyzed.
  • Antibody testing used the Euroimmun Anti-SARS-CoV-2-QuantiVac ELISA for spike S1 IgG (reported in BAU/mL), the Abbott Architect assay for nucleocapsid IgG, and an in-house serial dilution neutralization test with infectious SARS-CoV-2 in Vero cells under biosafety level 3 conditions. Side effects were captured by questionnaire.
  • Statistical comparisons used Fisher’s exact test or Pearson’s χ² test for categorical data, Mann-Whitney U tests for quantitative data, and simple linear regression for age–titer correlations.

Limitations

  • The paper does not present a dedicated limitations section. It notes that data on difficult-to-enroll groups such as those over 80 years are limited, and that the duration of vaccine protection remains unclear.
  • Evident from the text: the cohort came from a single nursing home, was heavily female (124 females vs 52 males), and did not assess T-cell responses or clinical outcomes. The study also compared two narrow age bands rather than a continuous age range, and vaccination was not randomized.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1093/cid/ciab381

Cites

11 of 11 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

0 of 16 cited sources checked · 0 supported · 0 flagged

  • Findingown data

    There was no general correlation between vaccination-induced SARS-CoV-2 spike-specific IgG or neutralizing antibody production and the presence or absence of individual postvaccination reaction reports.

    “However, there was no general correlation between vaccination-induced SARS-CoV-2 spike-specific IgG or neutralizing antibody production and the presence or absence of individual postvaccination reaction reports.”
    Quote in the paperSubstantial claim
  • Findingown data

    Across the entire cohort, there was a negative correlation between age and SARS-CoV-2 spike-specific IgG titer after both the first and second vaccinations.

    “A general age-dependent negative correlation in SARS-CoV-2 spike-specific IgG after both vaccinations is noticed throughout the entire cohort (Figure 1D and 1E).”
    • Also stated in: § DISCUSSION · plain
      “Additionally, a general intra-and inter-group trend in negative correlation between age and IgG titer is visible after both vaccinations (Figure 1C and 1D).”
    Quote in the paperSubstantial claim
  • Findingown data

    The majority of participants in both age groups produced specific IgG antibody titers against SARS-CoV-2 spike protein after vaccination.

    “Although the majority of participants in both groups produced specific immunoglobulin G antibody titers against SARS-CoV-2 spike protein, titers were significantly lower in elderly participants.”
    Quote in the paperSubstantial claim
  • Findingown data

    After the second vaccination, 2.2% of vaccinees younger than 60 years had no detectable neutralizing antibodies.

    “in contrast to the younger group, in which only 2.2% had no detectable neutralizing antibodies.”
    Quote in the paperSubstantial claim
  • Premisecitation

    Vaccine effectiveness is lower in individuals who received only the first dose compared with those who received the full vaccination regimen.

    “Studies suggest that effectiveness of the vaccine is lower in individuals who received only the first dose compared with individuals who received the full vaccination regimen [16,17].”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [16] Thompson, 2021, Interim estimates of vaccine effectiveness of BNT162b2 and mRNA-1273 COVID-19 vaccines in preventing SARS-CoV-2 infection among health care personnel, first responders, and other essential and frontline workers - eight U.S. locations, December 2020-March 2021, MMWR Morb Mortal Wkly Rep source

      Not checked in the free run.

    • cites [17] Britton, 2021, Effectiveness of the Pfizer-BioNTech COVID-19 vaccine among residents of two skilled nursing facilities experiencing COVID-19 outbreaks - Connecticut, December 2020-February 2021, MMWR Morb Mortal Wkly Rep source

      Not checked in the free run.

  • The quote only partly states this claim. 9
  • May combine two claims. 13
  • Classified as probably not a substantial claim. 5

  • The quote only partly states this claim.

    Findingown data

    After the first vaccination, the proportion of vaccinees with spike-specific IgG below the assay cutoff was higher in the >80-year group (65.9%) than in the <60-year group (4.4%).

    “Only 4.4% of the participants had titers below the cutoff, and 2.3% were indeterminate”
    • Also stated in: § Participant Characteristics · plain
      “In this group, 65.9% showed titers below the cutoff (>35.6), and 9.4% were indeterminate.”
    Quote in the paperSubstantial claim

  • May combine two claims. The quote only partly states this claim.

    Findingown data

    After the second vaccination, 25.8% of vaccinees younger than 60 years reported no postvaccination reactions, whereas 83.1% of vaccinees older than 80 years reported no reactions.

    “After the second dose, only 25.8% of the younger vaccinees had no postvaccination reactions.”
    • Also stated in: § The Severity of Postvaccination Reactions Does Not Correlate With Antibody Response · plain
      “Among the elderly, 83.1% reported no reaction, and the remaining 16.9% of this group reported combined reactions up to a score of 3 (Figure 3B).”
    Quote in the paperNot a substantial claim

  • May combine two claims. The quote only partly states this claim.

    Findingown data

    After the second vaccination, 10.6% of vaccinees older than 80 years had spike-specific IgG below the cutoff, whereas no vaccinee younger than 60 years had titers below the cutoff.

    “with no participant testing below cutoff”
    • Also stated in: § Participant Characteristics · plain
      “10.6% of the participants in this group still had titers below the cutoff.”
    Quote in the paperSubstantial claim

  • The quote only partly states this claim.

    Findingown data

    After the second BNT162b2 dose, the mean spike-specific IgG level was significantly lower in vaccinees older than 80 years (1332.0 BAU/mL) than in those younger than 60 years (3702.0 BAU/mL), with P < .0001.

    “The mean titer of the younger group increased more than 10-fold (3702.0BAU/mL) and ranged from 81.6 to 32 000.0 with no participant testing below cutoff”
    • Also stated in: § Participant Characteristics · plain
      “Although the mean titer for elderly vaccinees increased to 1332.0 BAU/mL (0-16 891.0 BAU/mL), 10.6% of the participants in this group still had titers below the cutoff.”
    • Also stated in: § Participant Characteristics · plain
      “Nevertheless, there was still a significant difference in IgG levels between the 2 groups (P < .0001).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    After the first vaccination, neutralizing antibodies were detected in 16.1% of vaccinees younger than 60 years and in 1.2% of vaccinees older than 80 years; the majority in both groups lacked neutralizing antibodies.

    “At 17-19 days after the first vaccination, the majority of participants, regardless of their age, failed to display neutralizing antibody titers.”
    • Also stated in: § Elderly Vaccinees Showed Reduced SARS-CoV-2 Neutralizing Capacity Compared With Younger Vaccinees · plain
      “In the group of younger vaccines, 16.1% displayed neutralizing antibodies with titers ranging between 1:10 and 1:2560.”
    • Also stated in: § Elderly Vaccinees Showed Reduced SARS-CoV-2 Neutralizing Capacity Compared With Younger Vaccinees · plain
      “In the group of elderly vaccinees, only 1.2% had developed neutralizing antibodies after the first vaccination (Figure 2A).”
    Quote in the paperSubstantial claim

  • The quote only partly states this claim.

    Findingown data

    After the first BNT162b2 dose, the mean SARS-CoV-2 spike S1-specific IgG level was significantly lower in vaccinees older than 80 years (41.2 BAU/mL) than in those younger than 60 years (313.3 BAU/mL), with P < .0001.

    “For the younger group of vaccinees, IgG titers ranged between 0 and 3840.0BAU/mL with a mean of 313.3 BAU/mL after the first vaccination.”
    • Also stated in: § Participant Characteristics · plain
      “The mean titer for the group > 80 years of age was 41.2 BAU/mL with titers ranging from 0 to 484.7 BAU/mL.”
    • Also stated in: § Participant Characteristics · plain
      “At this time point, quantitative SARS-CoV-2 spike S1-specific IgG levels between the 2 groups differed significantly (P < .0001).”
    Quote in the paperSubstantial claim

  • May combine two claims. The quote only partly states this claim.

    Findingown data

    After the first vaccination, 51.6% of vaccinees younger than 60 years reported no postvaccination reactions, whereas 93.9% of vaccinees older than 80 years reported no reactions.

    “After the first vaccination, one-half of the younger cohort (51.6%) reported no reactions to the vaccination, but the remaining vaccinees recorded reactions with a score ranging between 1 and 4 of combined reactions.”
    • Also stated in: § The Severity of Postvaccination Reactions Does Not Correlate With Antibody Response · plain
      “In turn, 93.9% of elderly vaccinees reported no postvaccination reactions; the remaining 6.1% reported either 1 or 2 of the scored reactions (Figure 3A).”
    Quote in the paperNot a substantial claim

  • The quote only partly states this claim.

    Findingown data

    The mean spike-specific IgG titer after the second vaccination remained 2.8-fold lower in vaccinees older than 80 years compared with those younger than 60 years.

    “the mean titer of SARS-CoV-2 spike-specific IgG remained 2.8fold lower after the second vaccination for the elderly group of vaccinees compared to the younger cohort (Figure 1B).”
    Quote in the paperSubstantial claim

  • May combine two claims. The quote only partly states this claim.

    Findingown data

    After the second vaccination, neutralizing antibodies were detected in 97.8% of vaccinees younger than 60 years and in 68.7% of vaccinees older than 80 years.

    “After the second dose, a neutralization titer was attained by 97.8% of the younger vaccinees.”
    • Also stated in: § Elderly Vaccinees Showed Reduced SARS-CoV-2 Neutralizing Capacity Compared With Younger Vaccinees · plain
      “In the elderly group, 68.7% showed titers ranging from 1:10 to 1:320.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The fold-increase in antibody levels after the second immunization was higher in elderly vaccinees older than 80 years than in younger vaccinees younger than 60 years, but the absolute mean titer remained lower in the elderly.

    “Although the increment of antibody levels after the second immunization was higher in elderly participants, the absolute mean titer of this group remained lower than the <60 years of age group.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductnone given

    The in-house SARS-CoV-2 neutralization test was performed as independent duplicates for each sample, with positive, negative, virus-only, and cell-growth controls run during each assay.

    “Tests were performed as independent duplicates for each sample.Positive, negative, virus only, and cell growth controls were run during each assay.”
    Quote in the paperNot a substantial claim

  • The quote only partly states this claim.

    Study design and conductown data

    Three vaccinees tested positive for SARS-CoV-2 nucleocapsid antibodies and were excluded from the dataset.

    “Three vaccinees tested positive and therefore were excluded from the dataset.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductown data

    The study used a cross-validation procedure in which a subset of samples from the first blood collection was run during analysis of samples from the second blood collection, and positive and negative samples were included in all assays.

    “For cross-validation, a subset of samples from the first blood collection were run during analysis of samples from the second blood collection.Positive and negative samples, which were previously tested, were included in all assay.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Adults older than 65 years accounted for approximately 80% of COVID-19 hospitalizations.

    “Here, the elderly population is primarily at risk for severe disease because adults older than 65 years of age accounted for approximately 80% of hospitalizations [19,20].”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [19] Mueller, 2020, Why does COVID-19 disproportionately affect older people?, Aging (Albany NY) source

      Not checked in the free run.

    • cites [20] Liu, 2020, Association between age and clinical characteristics and outcomes of COVID-19, Eur Respir J source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Premisecitation

    The BNT162b2 vaccination strategy is a two-step prime-and-boost procedure in which the first vaccination is followed by a second vaccination with the same dose at least 21 days later.

    “The current vaccination strategy for the Biontech/Pfizer Comirnaty (BNT162b2) is a 2-step”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [5] Polack, 2020, Safety and efficacy of the BNT162b2 mRNA covid-19 vaccine, N Engl J Med source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    In a large cohort study using BNT162b2 and BNT162b1, humoral responses in adults aged 18-55 and 65-85 were compared after the second vaccination, and immunogenicity including neutralization titers was lower in the elderly cohort.

    “In a large cohort study using the Biontech/Pfizer vaccine BNT162b2 and the related BNT162b1 vaccine candidate, the humoral responses in 2 adult age groups (18-55 and 65-85 years) were compared after the second vaccination.They reported that immunogenicity as measured by antibody responses including neutralization titers was lower in the elderly cohort and also discussed immunosenescence as”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [34] Walsh, 2020, Safety and immunogenicity of two RNA-based COVID-19 vaccine candidates, N Engl J Med source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Hallmarks of immunosenescence include decreased ability to respond to new antigens with reduced peripheral plasmablast response, decreased capacity of memory T cells, and low-level persistent chronic inflammation, leading to declining immune efficiency and increased susceptibility to infections and decreased response to vaccinations.

    “Although hallmarks of immunosenescence depend on multifaceted factors and vary greatly between individuals, they are considered to be related to (1) the decreased ability to respond to new antigens associated with a reduced peripheral plasmablast response, (2) decreased capacity of memory T cells, and (3) a low level of persistent chronic inflammation.This leads to declining immune efficiency and”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [23][24][25][26]

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Prolonged disease, delayed viral clearance, and a higher fatality rate are age-related in COVID-19.

    “Additionally, prolonged disease, delayed viral clearance, and a higher fatality rate is also reported to be age related [21].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [21] Leung, 2020, Clinical features of deaths in the novel coronavirus epidemic in China, Rev Med Virol source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Neutralizing antibody levels correlate with protection against many viruses including SARS-CoV-2 in humans, and high neutralizing titers are particularly important for protection against novel circulating SARS-CoV-2 variants.

    “The role of neutralizing antibodies is in particular crucial because neutralizing antibody levels correlate with protection against many viruses including SARS-CoV-2 in humans [35,36]; recent data suggest that high neutralizing titers are particularly important for protection against novel circulating SARS-CoV-2 variants conferring immune escape [37][38][39].”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites [35] Plotkin, 2010, Correlates of protection induced by vaccination, Clin Vaccine Immunol source

      Not checked in the free run.

    • cites [36] Iyer, 2020, Dynamics and significance of the antibody response to SARS-CoV-2 infection, medRxiv

      Not checked in the free run.

    • cites [37][38][39]

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Vaccine responses are often lower in elderly adults, especially for hepatitis B, pneumococcal, and influenza vaccinations, and this reduced success is attributed to adaptive immunosenescence.

    “Although vaccination is key to prevent infections, vaccine responses are often found to be lower in elderly adults.In numerous studies, the markedly reduced vaccine success in older adults has been attributed to adaptive immunosenescence.Reduced vaccination success in elderly adults is especially known for hepatitis B, pneumococcal, and influenza vaccinations [22,23].”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [22] Schenkelberg, 2021, Vaccine-induced protection in aging adults and pandemic response, Biochem Biophys Res Commun source

      Not checked in the free run.

    • cites [23] Crooke, 2019, Immunosenescence and human vaccine immune responses, Immun Ageing source

      Not checked in the free run.

20 of 20

  • The paper relies on this without support.

    The population older than 80 years is underrepresented in previous studies of COVID-19 vaccination.

    “Real-life data on immune responses elicited in the most vulnerable group of vaccinees older than age 80 years old are still underrepresented despite the prioritization of the elderly in vaccination campaigns.”
    “Despite the fact that the elderly age group is most vulnerable, this population was underrepresented in previous studies.”

  • The authors state this as an assumption.

    Single-dose vaccinees might still acquire SARS-CoV-2 infection and transmit the disease while remaining asymptomatic.

    “The observation that single-dose vaccinees broadly lacked neutralizing antibody responses in our cohort raises the question whether these individuals might still acquire infections and may transmit the disease while remaining asymptomatic.This assumption is supported by recent results of a large Israeli study that reports a 46% effectiveness in preventing a documented infection 14 to 20 days after”

  • The paper relies on this without support.

    The differences in antibody responses between the age groups are attributable to age rather than to other differences such as sex or comorbidity.

    “The main differences between the 2 groups are likely a consequence of immunosenescence, which describes the reduced adaptive immune responses in the elderly [29].”
3 of 3

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • In a more recent study with BNT162b2, people over 80 had lower anti-SARS-CoV-2 antibody titers 17 days after the second dose compared to those under 60, including 31% with no detectable neutralizing antibodies.

    “A more recent study with BNT162b2 showed that people over the age of 80 had lower anti-SARS-CoV-2 antibody titers seventeen days after the second dose when compared to those under 60 years of age, including 31% with no detectable neutralizing antibodies203.”

    From SARS-CoV-2, COVID-19 and the aging immune system (2021) · cites this paper as [203]

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • The stated tests for quantitative comparisons conflict

    Major

    The statistical-analysis section says quantitative data were analyzed with a nonparametric Mann-Whitney U test, whereas the Figure 1 caption says its group comparisons used parametric t tests.

  • The IgG positivity threshold changes in the figure caption

    Minor

    The assay description sets the upper indeterminate threshold at 35.2 BAU/mL, but the Figure 1 caption sets it at 35.6 BAU/mL. A result between those thresholds would receive different classifications.

  • Younger group's table percentage does not match its count

    Minor

    Table 1 lists 91 younger participants out of 176 as 53%; that count is 51.7% of the total.

    Reported 53 · recomputed 51.704545

  • Elderly group's table percentage does not match its count

    Minor

    Table 1 lists 85 elderly participants out of 176 as 47%; that count is 48.3% of the total.

    Reported 47 · recomputed 48.295455

  • Age-group counts differ between the results and Table 1

    Minor

    The results describe 93 younger and 83 elderly participants, while Table 1 lists 91 younger and 85 elderly participants. Both pairs total 176, but the age-group allocations conflict.

5 of 5

Cites

Flagged first, then by citations

Research works printed but not linked: 31

  1. Zhu, 2020, A novel coronavirus from patients with pneumonia in China, 2019, N Engl J Med, 382, 727, 10.1056/NEJMoa2001017 · DOI · Paper page
  2. Amanat, 2020, SARS-CoV-2 vaccines: status report, Immunity, 52, 583, 10.1016/j.immuni.2020.03.007 · DOI · Paper page
  3. Kaur, 2020, COVID-19 vaccine: a comprehensive status report, Virus Res, 288, 198114, 10.1016/j.virusres.2020.198114 · DOI
  4. Voysey, 2021, Safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) against SARS-CoV-2: an interim analysis of four randomised controlled trials in Brazil, South Africa, and the UK, Lancet, 397, 99, 10.1016/S0140-6736(20)32661-1 · DOI · Paper page
  5. Rawat, 2021, COVID-19 vaccine: a recent update in pipeline vaccines, their design and development strategies, Eur J Pharmacol, 892, 173751, 10.1016/j.ejphar.2020.173751 · DOI
  6. Schlake, 2012, Developing mRNA-vaccine technologies, RNA Biol, 9, 1319, 10.4161/rna.22269 · DOI · Paper page
  7. Pardi, 2020, Recent advances in mRNA vaccine technology, Curr Opin Immunol, 65, 14, 10.1016/j.coi.2020.01.008 · DOI · Paper page
  8. Wang, 2020, The COVID-19 vaccine race: challenges and opportunities in vaccine formulation, AAPS PharmSciTech, 21, 225, 10.1208/s12249-020-01744-7 · DOI
  9. Anderson, 2020, Safety and immunogenicity of SARS-CoV-2 mRNA-1273 vaccine in older adults, N Engl J Med, 383, 2427, 10.1056/NEJMoa2028436 · DOI · Paper page
  10. Amit, 2021, Early rate reductions of SARS-CoV-2 infection and COVID-19 in BNT162b2 vaccine recipients, Lancet, 397, 875, 10.1016/S0140-6736(21)00448-7 · DOI · Paper page
  11. Thompson, 2021, Interim estimates of vaccine effectiveness of BNT162b2 and mRNA-1273 COVID-19 vaccines in preventing SARS-CoV-2 infection among health care personnel, first responders, and other essential and frontline workers - eight U.S. locations, December 2020-March 2021, MMWR Morb Mortal Wkly Rep, 70, 495, 10.15585/mmwr.mm7013e3 · DOI · Paper page
  12. Britton, 2021, Effectiveness of the Pfizer-BioNTech COVID-19 vaccine among residents of two skilled nursing facilities experiencing COVID-19 outbreaks - Connecticut, December 2020-February 2021, MMWR Morb Mortal Wkly Rep, 70, 396, 10.15585/mmwr.mm7011e3 · DOI · Paper page
  13. Wu, 2020, Characteristics of and important lessons from the coronavirus disease 2019 (COVID-19) outbreak in China: summary of a report of 72314 cases from the Chinese center for disease control and prevention, JAMA, 323, 1239, 10.1001/jama.2020.2648 · DOI · Paper page
  14. Mueller, 2020, Why does COVID-19 disproportionately affect older people?, Aging (Albany NY), 12, 9959, 10.18632/aging.103344 · DOI · Paper page
  15. Liu, 2020, Association between age and clinical characteristics and outcomes of COVID-19, Eur Respir J, 55, 2001112, 10.1183/13993003.01112-2020 · DOI · Paper page
  16. Schenkelberg, 2021, Vaccine-induced protection in aging adults and pandemic response, Biochem Biophys Res Commun, 538, 218, 10.1016/j.bbrc.2020.10.090 · DOI · Paper page
  17. Crooke, 2019, Immunosenescence and human vaccine immune responses, Immun Ageing, 16, 25, 10.1186/s12979-019-0164-9 · DOI · Paper page
  18. Aiello, 2019, Immunosenescence and its hallmarks: how to oppose aging strategically? A review of potential options for therapeutic intervention, Front Immunol, 10, 2247, 10.3389/fimmu.2019.02247 · DOI · Paper page
  19. Lau, 2021, Neutralizing antibody titres in SARS-CoV-2 infections, Nat Commun, 12, 63, 10.1038/s41467-020-20247-4 · DOI
  20. Muller, 2021, Sensitivity of anti-SARS-CoV-2 serological assays in a high-prevalence setting, Eur J Clin Microbiol Infect Dis, 40, 1063, 10.1007/s10096-021-04169-7 · DOI
  21. Gustafson, 2020, Influence of immune aging on vaccine responses, J Allergy Clin Immunol, 145, 1309, 10.1016/j.jaci.2020.03.017 · DOI
  22. Frasca, 2020, Aging induces B cell defects and decreased antibody responses to influenza infection and vaccination, Immun Ageing, 17, 37, 10.1186/s12979-020-00210-z · DOI · Paper page
  23. Walsh, 2020, Safety and immunogenicity of two RNA-based COVID-19 vaccine candidates, N Engl J Med, 383, 2439, 10.1056/NEJMoa2027906 · DOI · Paper page
  24. Plotkin, 2010, Correlates of protection induced by vaccination, Clin Vaccine Immunol, 17, 1055, 10.1128/CVI.00131-10 · DOI · Paper page
  25. Iyer, 2020, Dynamics and significance of the antibody response to SARS-CoV-2 infection, medRxiv
  26. Garcia-Beltran, 2021, Circulating SARS-CoV-2 variants escape neutralization by vaccine-induced humoral immunity, medRxiv
  27. Jangra, 2021, The E484K mutation in the SARS-CoV-2 spike protein reduces but does not abolish neutralizing activity of human convalescent and post-vaccination sera, medRxiv
  28. Kuzmina, 2021, SARS CoV-2 escape variants exhibit differential infectivity and neutralization sensitivity to convalescent or post-vaccination sera, 10.1101/2021.02.22.21252002 · DOI
  29. Robertson, 2021, Delayed second dose of the BNT162b2 vaccine: innovation or misguided conjecture?, Lancet, 397, 879, 10.1016/S0140-6736(21)00455-4 · DOI
  30. Bieniasz, 2021, The case against delaying SARS-CoV-2 mRNA vaccine boosting doses, Clin Infect Dis, ciab070
  31. Forman, 2021, COVID-19 vaccine challenges: what have we learned so far and what remains to be done?, Health Policy, 125, 553, 10.1016/j.healthpol.2021.03.013 · DOI

Cited by

Sorted by citations

Authors
Müller, L., Andrée, M., Moskorz, W., Drexler, I., Walotka, L., Grothmann, R., Ptok, J., Hillebrandt, J., Ritchie, A., Rabl, D., Ostermann, P. N., Robitzsch, R., Hauka, S., Walker, A., Menne, C., Grutza, R., Timm, J., Adams, O., & Schaal, H.
Affiliations
Düsseldorf University Hospital (DE)
Corresponding author
Müller, Lisa
ORCID
Venue
Clinical Infectious Diseases
Publisher
Oxford University Press (OUP)
Published
2021-04-27
Volume
73
Issue
11
Pages
2065-2072
ISSN
  • 1058-4838 (ISSN-L)
  • 1537-6591
DOI
10.1093/cid/ciab381
PMC
PMC8135422
OpenAlex
W3158247426
Cited by
511
References
11
Citations by year
2026: 12 · 2025: 25 · 2024: 47 · 2023: 89 · 2022: 207 · 2021: 129
FWCI
37.97
Type
journal article
Language
en
Open access
Licence
academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model (vor)
Locations
  • Clinical Infectious Diseases (publishedVersion)
  • medRxiv (acceptedVersion, cc-by-nc-nd)
  • PubMed Central (publishedVersion)
  • PubMed (publishedVersion)
Funders
  • Stiftung für Altersforschung, Düsseldorf
  • Jürgen Manchot foundation
  • Deutsche Forschungsgemeinschaft
  • German Research Foundation (GK1949/1)
  • Forschungskommission of the Medical Faculty
  • Heinrich-Heine-Universität Düsseldorf
Topics
  • Health Sciences › Medicine › Infectious Diseases › SARS-CoV-2 and COVID-19 Research
  • Life Sciences › Immunology and Microbiology › Immunology › Immune responses and vaccinations
  • Social Sciences › Health › Vaccine Coverage and Hesitancy
Keywords
BNT162b2, COVID-19 vaccines, SARS-CoV-2, vaccine antibody response, neutralizing antibodies, immunosenescence, older adults, age differences, IgG, booster vaccination, vaccine dose
MeSH terms
COVID-19, BNT162 Vaccine, Age Factors, Aged, Aged, 80 and over, Antibodies, Viral, Female, Humans, Immunoglobulin G, Immunity, Male, Middle Aged, Vaccination, Cohort Studies, Antibodies, Neutralizing, Spike Glycoprotein, Coronavirus

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-06.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-06.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review