CoChat
Sign Up
Cited by 1,703SARS-CoV-2 and COVID-19 ResearchImmune responses and vaccinationsVaccine Coverage and Hesitancy

Waning Immune Humoral Response to BNT162b2 Covid-19 Vaccine over 6 Months

Open access
Levin, Einav G., Lustig, Yaniv, Cohen, Carmit, Fluss, Ronen, Indenbaum, Victoria, Amit, Sharon, Doolman, Ram, Asraf, Keren +6 more·2021·New England Journal of Medicine
DOI 10.1056/nejmoa2114583PMC PMC8522797
Open this paper in CoChat — free account

Abstract

BACKGROUND: Despite high vaccine coverage and effectiveness, the incidence of symptomatic infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been increasing in Israel. Whether the increasing incidence of infection is due to waning immunity after the receipt of two doses of the BNT162b2 vaccine is unclear. METHODS: We conducted a 6-month longitudinal prospective study involving vaccinated health care workers who were tested monthly for the presence of anti-spike IgG and neutralizing antibodies. Linear mixed models were used to assess the dynamics of antibody levels and to determine predictors of antibody levels at 6 months. RESULTS: The study included 4868 participants, with 3808 being included in the linear mixed-model analyses. The level of IgG antibodies decreased at a consistent rate, whereas the neutralizing antibody level decreased rapidly for the first 3 months with a relatively slow decrease thereafter. Although IgG antibody levels were highly correlated with neutralizing antibody titers (Spearman's rank correlation between 0.68 and 0.75), the regression relationship between the IgG and neutralizing antibody levels depended on the time since receipt of the second vaccine dose. Six months after receipt of the second dose, neutralizing antibody titers were substantially lower among men than among women (ratio of means, 0.64; 95% confidence interval [CI], 0.55 to 0.75), lower among persons 65 years of age or older than among those 18 to less than 45 years of age (ratio of means, 0.58; 95% CI, 0.48 to 0.70), and lower among participants with immunosuppression than among those without immunosuppression (ratio of means, 0.30; 95% CI, 0.20 to 0.46). CONCLUSIONS: Six months after receipt of the second dose of the BNT162b2 vaccine, humoral response was substantially decreased, especially among men, among persons 65 years of age or older, and among persons with immunosuppression.

Integrity signals

Registry

Crossref · 10.1056/nejmoa2114583

Cites

Statistics

Nothing to recompute.

Claims the paper makes

0 of 28 cited sources checked · 0 supported · 0 flagged

  • Findingown data

    For neutralizing antibodies, the correlation between peak levels and rates of decline was strongly negative (−0.63; 95% CI, −0.70 to −0.55).

    “However, for neutralizing antibody, the correlation was strongly negative (−0.63; 95% CI, −0.70 to −0.55).”
    Quote in the paperSubstantial claim
  • Findingown data

    At 6 months after the second dose, men had lower neutralizing antibody titers than women, with a ratio of means of 0.64 (95% CI, 0.55 to 0.75).

    “Six months after receipt of the second dose, neutralizing antibody titers were substantially lower among men than among women (ratio of means, 0.64; 95% confidence interval [CI], 0.55 to 0.75)”
    Quote in the paperSubstantial claim
  • Findingown data

    There was an age-by-sex interaction: the reduction in titers for men aged 45 or older versus younger men was larger than the corresponding difference among women.

    “An age-by-sex interaction was found; the difference by which the titers in men 45 years of age or older were lower than the titers in men younger than 45 years of age was larger than the difference between the corresponding female groups.”
    Quote in the paperNot a substantial claim
  • Findingown data

    Obese participants (BMI ≥30) had 31% higher neutralizing antibody concentrations than nonobese participants.

    “Obese participants (those with a BMI of ≥30) had a 31% increase in neutralizing antibody concentrations as compared with nonobese participants (Table 1).”
    • Also stated in: § Discussion · plain
      “Obese persons (BMI, ≥30) had a significantly higher neutralizing antibody titer during long-term follow-up than nonobese participants.”
    Quote in the paperNot a substantial claim
  • Findingown data

    At end of study, men aged 65 or older had 37% lower IgG and 46% lower neutralizing antibody concentrations than women of the same age group.

    “and of 37% and 46%, respectively, among men 65 years of age or older as compared with women in the same age group (Table 1).”
    Quote in the paperNot a substantial claim
  • May combine two claims. 20
  • Classified as probably not a substantial claim. 7

  • May combine two claims.

    Findingown data

    Immunosuppressed participants had 65% lower IgG and 70% lower neutralizing antibody concentrations than non-immunosuppressed participants.

    “Participants with immunosuppression had decreases in the IgG and neutralizing antibody concentrations of 65% and 70%, respectively, as compared with participants without immunosuppression.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    After adjustment, higher initial neutralizing antibody levels were associated with faster decline up to about 70 days after the second dose; after that, decay was modest and similar across participants.

    “After adjustment for other factors, participants with a higher initial level tended to have a decrease that was faster up to approximately 70 days after receipt of the second dose. Beyond that time, rates of decay were modest and did not vary much among participants.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    For IgG, the correlation between individual peak levels and rates of decline was weak and positive (0.17; 95% CI, 0.11 to 0.24), indicating decay rates were not strongly related to initial levels.

    “For IgG levels, the correlation between individual participants’ peak levels and their slopes of the decrease was positive but weak (0.17; 95% CI, 0.11 to 0.24); the rates of decay were not strongly related to initial levels.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Neutralizing antibody titers fell sharply during the first roughly 3 months after the second dose and then declined more slowly.

    “the neutralizing antibody level decreased rapidly for the first 3 months with a relatively slow decrease thereafter.”
    • Also stated in: § SARS-CoV-2 Antibody Kinetics after Receipt of Second Vaccine Dose · plain
      “Neutralizing antibody titers also decreased significantly, with a decrease by a factor of 3.9 from the peak to the end of study period 2, but the decrease from the start of period 3 onward was much slower, with an overall decrease by a factor of 1.2 during periods 3 through 6.”
    • Also stated in: § Discussion · plain
      “The decrease in neutralizing antibody titers was brisk initially, in the period of up to 70 to 80 days, but slowed thereafter.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Neutralizing antibody titers were significantly lower with older age, male sex, and immunosuppression, and significantly higher with obesity (BMI ≥30) in both peak and end-of-study periods.

    “Significantly lower neutralizing antibody titers were associated with older age, male sex, and the presence of immunosuppression in both periods, and significantly higher neutralizing antibody titers were associated with a BMI of 30 or higher (obesity) as compared with a BMI of less than 30 in both study periods.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    In both peak and 6-month periods, antibody levels were higher in women than men and declined with older age.

    “We found that antibody levels in both periods were higher in women than in men and decreased with age, as has been previously shown for the first month after receipt of the second dose.7,16”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [7] Lustig Y, Sapir E, Regev-Yochay G, et al. BNT162b2 COVID-19 vaccine and correlates of humoral immune responses and dynamics: a prospective, single-centre, longitudinal cohort study in health-care workers. Lancet Respir Med 2021; 9: 999- 1009. 34224675 PMC8253545 source

      Not checked in the free run.

    • cites [16] Bates TA, Leier HC, Lyski ZL, et al. Age-dependent neutralization of SARS-CoV-2 and P.1 variant by vaccine immune serum samples. JAMA 2021 July 21 (Epub ahead of print). 34287620 PMC8295896 source

      Not checked in the free run.

  • May combine two claims.

    Findingown data

    For healthy women aged 18 to <45, 45 to <65, and ≥65 years, the predicted probability of a neutralizing antibody titer below 256 at 175 days was 0.68, 0.79, and 0.81; for men, it was 0.75, 0.89, and 0.92.

    “Among healthy women and men in the three age groups (18 to <45 years, 45 to <65 years, and ≥65 years of age), the probability of having a neutralizing antibody titer of less than 256 at 175 days after receipt of the second dose were as follows: 0.68, 0.79, and 0.81, respectively, among women and 0.75, 0.89, and 0.92, respectively, among men.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    At both peak and end of study, IgG titers were significantly lower with older age, male sex, two or more specified coexisting conditions, autoimmune disease, and immunosuppression.

    “In the peak and end-of-study periods, significantly lower IgG titers were associated with older age, male sex, the presence of two or more coexisting conditions (i.e., hypertension, diabetes, dyslipidemia, or heart, lung, kidney, or liver disease), the presence of autoimmune disease, and the presence of immunosuppression.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Compared with participants aged 18 to less than 45 years, those aged 65 or older had lower peak IgG and neutralizing antibody levels and a larger decline in neutralizing antibody titers through about 3 months.

    “Participants 65 years of age or older had lower IgG and neutralizing antibody levels than persons 18 to less than 45 years of age during the peak period and also had a greater decrease, up to approximately 3 months (end of period 2), in the neutralizing antibody titer”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    During peak, participants with two or more specified coexisting conditions had lower IgG and neutralizing antibody titers than those with none, but at end of study neutralizing antibody differences were not significant.

    “Our results show that although the IgG and neutralizing antibody titers were significantly lower in participants with two or more specific coexisting conditions than in those with no specific coexisting condition during the peak period, no significant differences in neutralizing antibody titers were observed at the end of study.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    For healthy women aged 18 to <45, 45 to <65, and ≥65 years, the predicted probability of a neutralizing antibody titer below 16 at 175 days was 0.02, 0.05, and 0.06; for men, it was 0.04, 0.11, and 0.15.

    “The probability of having a neutralizing antibody titer of less than 16 in these three age groups (18 to <45 years, 45 to <65 years, and ≥65 years of age) were as follows: 0.02, 0.05, and 0.06, respectively, among women and 0.04, 0.11, and 0.15, respectively, among men.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingcitation

    Participants with immunosuppression had consistently lower antibody responses, with neutralizing antibody titers five times lower than those without immunosuppression.

    “Similar to the findings in other reports,17-19 a significantly lower antibody response was found consistently through the observation period among participants with immunosuppression, who had neutralizing antibody titers that were lower by a factor of 5 than those among participants without immunosuppression.”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites [17] Boyarsky BJ, Werbel WA, Avery RK, et al. Antibody response to 2-dose SARS-CoV-2 mRNA vaccine series in solid organ transplant recipients. JAMA 2021; 325: 2204- 2206. 33950155 PMC8100911 source

      Not checked in the free run.

    • cites [18] Marion O, Del Bello A, Abravanel F, et al. Safety and immunogenicity of anti-SARS-CoV-2 messenger RNA vaccines in recipients of solid organ transplants. Ann Intern Med 2021; 174: 1336- 1338. 34029487 PMC8252830 source

      Not checked in the free run.

    • cites [19] Goshen-Lago T, Waldhorn I, Holland R, et al. Serologic status and toxic effects of the SARS-CoV-2 BNT162b2 vaccine in patients undergoing treatment for cancer. JAMA Oncol 2021 July 8 (Epub ahead of print). 34236381 PMC8267843 source

      Not checked in the free run.

  • May combine two claims.

    Findingown data

    Neutralizing antibody titers fell 3.9-fold from peak to the end of period 2, then declined only 1.2-fold across periods 3 through 6.

    “Neutralizing antibody titers also decreased significantly, with a decrease by a factor of 3.9 from the peak to the end of study period 2, but the decrease from the start of period 3 onward was much slower, with an overall decrease by a factor of 1.2 during periods 3 through 6.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The geometric mean 50% neutralization titer was 557.1 (95% CI, 510.8 to 607.7) at peak and 119.4 (95% CI, 112.0 to 127.3) in period 6.

    “The GMT of neutralizing antibody, expressed as a 50% neutralization titer, was 557.1 (95% CI, 510.8 to 607.7) in the peak period and decreased to 119.4 (95% CI, 112.0 to 127.3) in period 6.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Autoimmune disease was associated with significantly lower IgG titers but not neutralizing antibody titers at both peak and end of study.

    “In addition, participants with autoimmune disease had a significantly lower IgG titer but not neutralizing antibody titer during both the peak and end-of-study periods than did those without autoimmune disease.”
    Quote in the paperSubstantial claim

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

    Premisecitation

    The BNT162b2 vaccine has shown 94 to 95% efficacy and real-world effectiveness against symptomatic Covid-19 from 7 days after the second dose.

    “A randomized, controlled trial and real-world studies have shown vaccine efficacy of 94 to 95% with the BNT162b2 vaccine (Pfizer–BioNTech) and vaccine effectiveness in preventing symptomatic coronavirus disease 2019 (Covid-19) 7 days or more after receipt of the second dose of vaccine.1,3-5”
    Quote in the paperNot a substantial claim0 of 4 sources checked
    • cites [1] Polack FP, Thomas SJ, Kitchin N, et al. Safety and efficacy of the BNT162b2 mRNA Covid-19 vaccine. N Engl J Med 2020; 383: 2603- 2615. 33301246 PMC7745181 source

      Not checked in the free run.

    • cites [3] Dagan N, Barda N, Kepten E, et al. BNT162b2 mRNA Covid-19 vaccine in a nationwide mass vaccination setting. N Engl J Med 2021; 384: 1412- 1423. 33626250 PMC7944975 source

      Not checked in the free run.

    • cites [4] Haas EJ, Angulo FJ, McLaughlin JM, et al. Impact and effectiveness of mRNA BNT162b2 vaccine against SARS-CoV-2 infections and COVID-19 cases, hospitalisations, and deaths following a nationwide vaccination campaign in Israel: an observational study using national surveillance data. Lancet 2021; 397: 1819- 1829. 33964222 PMC8099315 source

      Not checked in the free run.

    • cites [5] Chodick G, Tene L, Rotem RS, et al. The effectiveness of the two-dose BNT162b2 vaccine: analysis of real-world data. Clin Infect Dis 2021 May 17 (Epub ahead of print). 33999127 PMC8240867 source

      Not checked in the free run.

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

    Premisecitation

    For vaccines such as measles, mumps, and rubella, published studies have shown neutralizing antibody levels decline by about 5 to 10% per year.

    “Published work about many vaccines, such as those against measles, mumps, and rubella, has shown a small decrease each year of 5 to 10% in the neutralizing antibody levels.13,14”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [13] Davidkin I, Jokinen S, Broman M, Leinikki P, Peltola H. Persistence of measles, mumps, and rubella antibodies in an MMR-vaccinated cohort: a 20-year follow-up. J Infect Dis 2008; 197: 950- 956. 18419470 source

      Not checked in the free run.

    • cites [14] Seagle EE, Bednarczyk RA, Hill T, et al. Measles, mumps, and rubella antibody patterns of persistence and rate of decline following the second dose of the MMR vaccine. Vaccine 2018; 36: 818- 826. 29317117 source

      Not checked in the free run.

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

    Premisecitation

    Obesity is associated with severe Covid-19.

    “Obesity is associated with severe Covid-19,20”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [20] Huang Y, Lu Y, Huang Y-M, et al. Obesity in patients with COVID-19: a systematic review and meta-analysis. Metabolism 2020; 113: 154378- 154378. 33002478 PMC7521361 source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Older age, male sex, and immunosuppression have been associated with lower antibody levels after vaccination.

    “Lower antibody levels have been shown to develop in older persons, men, and persons with an immunosuppressed condition, which suggests that antibody titers in these populations may decrease earlier than in other populations.7,8”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [7] Lustig Y, Sapir E, Regev-Yochay G, et al. BNT162b2 COVID-19 vaccine and correlates of humoral immune responses and dynamics: a prospective, single-centre, longitudinal cohort study in health-care workers. Lancet Respir Med 2021; 9: 999- 1009. 34224675 PMC8253545 source

      Not checked in the free run.

    • cites [8] Terpos E, Trougakos IP, Apostolakou F, et al. Age-dependent and gender-dependent antibody responses against SARS-CoV-2 in health workers and octogenarians after vaccination with the BNT162b2 mRNA vaccine. Am J Hematol 2021; 96(7): E257- E259. 33837984 PMC8250071 source

      Not checked in the free run.

  • May combine two claims.

    Interpretationown data

    Humoral immunity declined substantially by 6 months after the second BNT162b2 dose, with greater declines in men, people aged 65 or older, and immunosuppressed individuals.

    “Six months after receipt of the second dose of the BNT162b2 vaccine, humoral response was substantially decreased, especially among men, among persons 65 years of age or older, and among persons with immunosuppression.”
    • Also stated in: § Discussion · plain
      “we found a significant waning of humoral responses within 6 months after receipt of the second dose of BNT162b2 vaccine in a large cohort of 4868 participants.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Study design and conductreasoning

    To improve representativeness, neutralizing antibody testing was done in a subgroup enriched for older people and those with coexisting conditions, while IgG testing covered the entire study population.

    “To overcome this limitation, although IgG tests were performed in the entire study population, neutralizing antibody tests were performed in a subgroup that included higher proportions of older persons or of persons with coexisting conditions in order to better represent the general population.”
    Quote in the paperSubstantial claim

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

    Premisecitation

    A recent study found a positive association between SARS-CoV-2 neutralizing antibodies and BMI.

    “A recent study showed that SARS-CoV-2 neutralizing antibodies are positively associated with BMI.21”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [21] Soffer S, Glicksberg BS, Zimlichman E, et al. The association between obesity and peak antibody titer response in COVID-19 infection. Obesity (Silver Spring) 2021; 29: 1547- 1553. 33945220 PMC8242567 source

      Not checked in the free run.

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

    Study design and conductnone given

    All study participants provided written informed consent.

    “Written informed consent was obtained from all study participants.”
    Quote in the paperNot a substantial claim

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

    Study design and conductnone given

    The study protocol received approval from the institutional review board at Sheba Medical Center.

    “The study protocol was approved by the institutional review board at Sheba Medical Center.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationcitation

    Taken together, evidence from this study and others indicates that previously infected people have better long-term humoral response and vaccine effectiveness than recipients of two vaccine doses.

    “Overall, the accumulating evidence from our study and others22-25 shows that long-term humoral response and vaccine effectiveness in previously infected persons were superior to that in recipients of two doses of vaccine.”
    Quote in the paperSubstantial claim0 of 4 sources checked
    • cites [22] Dan JM, Mateus J, Kato Y, et al. Immunological memory to SARS-CoV-2 assessed for up to 8 months after infection. Science 2021; 371(6529): eabf4063- eabf4063. 33408181 PMC7919858 source

      Not checked in the free run.

    • cites [23] Vanshylla K, Di Cristanziano V, Kleipass F, et al. Kinetics and correlates of the neutralizing antibody response to SARS-CoV-2 infection in humans. Cell Host Microbe 2021; 29(6): 917- 929.e4. 33984285 PMC8090990 source

      Not checked in the free run.

    • cites [24] Anderson M, Stec M, Rewane A, Landay A, Cloherty G, Moy J. SARS-CoV-2 antibody responses in infection-naïve or previously infected individuals after 1 and 2 doses of the BNT162b2 vaccine. JAMA Netw Open 2021; 4(8): e2119741- e2119741. 34357399 PMC8346938 source

      Not checked in the free run.

    • cites [25] Hall VJ, Foulkes S, Charlett A, et al. SARS-CoV-2 infection rates of antibody-positive compared with antibody-negative health-care workers in England: a large, multicentre, prospective cohort study (SIREN). Lancet 2021; 397: 1459- 1469. 33844963 PMC8040523 source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Study design and conductreasoning

    The linear mixed model used in the analysis accounted for missing outcomes.

    “These and other missing outcomes were accommodated through the linear mixed model that was used in the analysis (described below).”
    Quote in the paperSubstantial claim
26 of 26

  • The authors state this as an assumption.

    Missing IgG and neutralizing antibody data were missing at random.

    “Missing data regarding IgG or neutralizing antibody levels were accommodated within these models under the “missing at random” assumption.”

  • The paper relies on this without support.

    No threshold neutralizing antibody titer for predicting breakthrough infection has been established.

    “However, a threshold titer that can predict breakthrough infection has not been defined.”
    “although the specific threshold titer that can predict breakthrough infection is still undefined”

  • The paper relies on this without support.

    Evidence on how long vaccine protection lasts is limited.

    “As the rollout of vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)1,2 is expanding worldwide, data on the durability of protection are limited.”

  • The paper relies on this without support.

    The full duration of immunity after vaccination is not yet known.

    “Real-world effectiveness and immunogenicity data describing the antibody kinetics over time after vaccination are beginning to appear, but a complete picture of the duration of immunity is not yet available.”

  • The paper relies on this without support.

    More severe Covid-19 is associated with a higher humoral immune response.

    “Obesity is associated with severe Covid-19,20 and disease severity is associated with a higher Covid-19 humoral immune response.”

  • The paper relies on this without support.

    The BNT162b2 vaccine produces high IgG and neutralizing antibody responses 7 to 14 days after the second dose.

    “The BNT162b2 vaccine elicits high IgG and neutralizing antibody responses 7 to 14 days after receipt of the second dose.”

  • The paper relies on this without support.

    Neutralizing antibody assays are complex and time-consuming.

    “Yet, neutralizing assays are complex and time-consuming.”
7 of 7

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?

No citation lists for this paper

No citation lists for this paper yet — checked again daily.

References 25 · Cited by 1,703

Authors
Levin, E. G., Lustig, Y., Cohen, C., Fluss, R., Indenbaum, V., Amit, S., Doolman, R., Asraf, K., Mendelson, E., Ziv, A., Rubin, C., Freedman, L., Kreiss, Y., & Regev-Yochay, G.
Affiliations
Sheba Medical Center (IL)
Corresponding author
Regev-Yochay, Gili
ORCID
Venue
New England Journal of Medicine
Publisher
Massachusetts Medical Society
Published
2021-12-09
Volume
385
Issue
24
Pages
e84-e84
ISSN
  • 0028-4793 (ISSN-L)
  • 1533-4406
DOI
10.1056/nejmoa2114583
PMC
PMC8522797
OpenAlex
W3203611764
Cited by
1,703
References
25
Citations by year
2026: 75 · 2025: 111 · 2024: 200 · 2023: 421 · 2022: 787 · 2021: 107 · 2020: 1
FWCI
120.04
Type
journal article
Language
en
Open access
Locations
  • New England Journal of Medicine (publishedVersion)
  • PubMed Central (publishedVersion)
  • PubMed (publishedVersion)
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, waning immunity, humoral immune response, neutralizing antibodies, anti-spike IgG, antibody decline, sex differences, age differences, immunosuppression, healthcare workers, SARS-CoV-2 reinfection
MeSH terms
Immunogenicity, Vaccine, COVID-19, Vaccine Efficacy, BNT162 Vaccine, Adult, Age Factors, Aged, Antibodies, Viral, Female, Health Personnel, Humans, Immunoglobulin G, Immunization, Secondary, Israel, Male, Middle Aged, Sex Factors, Time Factors, Cohort Studies, Body Mass Index, Linear Models, Immunocompromised Host, Antibodies, Neutralizing

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