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Vaccination effectiveness dropped from 83 percent to ZERO after 9 months (Sweden, preprint) – Oct 2021

Effectiveness of Covid-19 vaccination against risk of symptomatic infection, hospitalization, and death up to 9 months: a Swedish total-population cohort study

Peter Nordstrom, MD, PhD peter.nordstrom at umu.se, Marcel Ballin, MSc., Anna Nordstrom, MD, pmd

  1. Department of Community Medicine and Rehabilitation, Unit of Geiiatric Medicine, Umea University, Umea, Sweden (Peter Nordstrom and Marcel Ballin)
  2. Department of Public Health and Clinical Medicine, Section of Sustainable Health, Umea University, Umea, Sweden (Marcel Ballin and Anna Nordstrom)
  3. School of Sport Sciences, UiT the Arctic University of Norway, Tromso, Norway (Anna Nordstrom)


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After 9 months some people who had gottten vaccinated were
MORE LIKELY to get infected than those who had not been vaccinated

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Background: Whether vaccine effectiveness against Coronavirus disease 2019 (Covid-19) lasts longer than 6 months is unclear.

Methods: A retrospective cohort study was conducted using Swedish nationwide registries. The cohort comprised 842,974 pairs (N=1,684,958), including individuals vaccinated with 2 doses of

  • ChAdOxl nCoV-19,
  • mRNA-1273, or
  • BNT162b2,

and matched unvaccinated individuals. Cases of symptomatic infection and severe Covid-19 (hospitalization or 30-day mortality after confirmed infection) were collected from 12 January to 4 October 2021.

Findings: Vaccine effectiveness of BNT162b2 against infection waned progressively from 92% (95% CI, 92-93, P<0-001) at day 15-30 to 47% (95% CI, 39-55, P<0-001) at day 121-180, and from day 211 and onwards no effectiveness could be detected (23%; 95% CI, -2-41, P=0-07). The effectiveness waned slightly slower rr mRNA-1273, being estimated to 59% (95% CI, 18-79) from day 181 and onwards. In contrast, effectiveness of ChAdOx1 nCoV-19 was generally lower and waned faster, with no effectiveness detected from day 121 and onwards (-19%, 95% CI, -97-28), whereas effectiveness from heterologous ChAdOx1 nCoV- 19 / mRNA was maintained from 121 days and onwards (66%; 95% CI, 41-80). Overall, vaccine effectiveness was fver and waned faster among men and older individuals. For the outcome severe Covid-19, effectiveness waned from 89% (95% CI, 82-93, P<0-001) at day 15-30 to 42% (95% CI, -35-75, P=0-21) from day 181 and onwards, with sensitivity analyses showing notable waning among men, older frail individuals, and individuals with comorbidities.

Interpretation: Vaccine effectiveness against symptomatic Covid-19 infection wanes progressively over time across all subgroups, but at different rate according to type of vaccine, and faster for men and older frail individuals. The effectiveness against severe illness seems to remain high through 9 months, although not for men, older frail individuals, and individuals with comorbidities. This strengthens the evidence-based rationale for administration of a third booster dose.
 Download the PDF from VitaminDWiki


Swedish preprint is based on very recent data (thru Oct 4) for >1,000,000 people for 3 vaccines
No indications of effectiveness against asymptomatic infections or those that resulted in death

between jabs to 6 weeks in mid March''


This Swedish study was mentioned on the web


Created by admin. Last Modification: Friday October 29, 2021 20:19:36 GMT-0000 by admin. (Version 8)

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16514 Sweden symptoms.jpg admin 29 Oct, 2021 19:59 49.52 Kb 1528
16513 Sweden severe.jpg admin 29 Oct, 2021 18:13 44.79 Kb 1460
16511 Lancet effectivness PP.pdf PDF 2021 admin 29 Oct, 2021 18:12 962.45 Kb 382
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