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Background Reports of waning vaccine-induced immunity against COVID-19 have begun to surface. With that, the comparable long-term protection conferred by previous infection with SARS-CoV-2 remains unclear.
Methods We conducted a retrospective observational study comparing three groups: (1)SARS-CoV-2-naïve individuals who received a two-dose regimen of the BioNTech/Pfizer mRNA BNT162b2 vaccine, (2)previously infected individuals who have not been vaccinated, and (3)previously infected and single dose vaccinated individuals. Three multivariate logistic regression models were applied. In all models we evaluated four outcomes: SARS-CoV-2 infection, symptomatic disease, COVID-19-related hospitalization and death. The follow-up period of June 1 to August 14, 2021, when the Delta variant was dominant in Israel.
Results SARS-CoV-2-naïve vaccinees had a 13.06-fold (95% CI, 8.08 to 21.11) increased risk for breakthrough infection with the Delta variant compared to those previously infected, when the first event (infection or vaccination) occurred during January and February of 2021. The increased risk was significant ( P <0.001) for symptomatic disease as well. When allowing the infection to occur at any time before vaccination (from March 2020 to February 2021), evidence of waning natural immunity was demonstrated, though SARS-CoV-2 naïve vaccinees had a 5.96-fold (95% CI, 4.85 to 7.33) increased risk for breakthrough infection and a 7.13-fold (95% CI, 5.51 to 9.21) increased risk for symptomatic disease. SARS-CoV-2-naïve vaccinees were also at a greater risk for COVID-19-related-hospitalizations compared to those that were previously infected.
Conclusions This study demonstrated that natural immunity confers longer lasting and stronger protection against infection, symptomatic disease and hospitalization caused by the Delta variant of SARS-CoV-2, compared to the BNT162b2 two-dose vaccine-induced immunity. Individuals who were both previously infected with SARS-CoV-2 and given a single dose of the vaccine gained additional protection against the Delta variant.
### Competing Interest Statement
The authors have declared no competing interest.
### Funding Statement
There was no external funding for the project.
### Author Declarations
I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.
Yes
The details of the IRB/oversight body that provided approval or exemption for the research described are given below:
This study was approved by the MHS (Maccabi Healthcare Services) Institutional Review Board (IRB). Due to the retrospective design of the study, informed consent was waived by the IRB, and all identifying details of the participants were removed before computational analysis.
All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived.
Yes
I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).
Yes
I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable.
Yes
According to the Israel Ministry of Health regulations, individual-level data cannot be shared openly. Specific requests for remote access to de-identified community-level data should be directed to KSM, Maccabi Healthcare Services Research and Innovation Center.
sigpic Free at last, they took your life
They could not take your PRIDE
Per adesso tutti gli studi hanno detto che i guariti sono molto più protetti di chi ha fatto doppia dose di vaccino, quindi ribadisco: perché, per avere il green pass, devi per forza farmi una dose di vaccino?
Inoltre perché il mio green pass inizia dal primo tampone positivo e non da quello negativo?
Sylvester, sono la persona più lontana da no-vax/si-vax, cerco di basarmi, come fanno un po’ tutti, sulle evidenze che escono mano mano.
Sono d'accordo con te in tutto....
Trovo assurdo che un guarito non possa ottenere il GP dopo regolare sierologico.
"Pensare alla morte, pregare. C'è pure chi ha ancora questo bisogno, e se ne fanno voce le campane.
Io non l'ho più questo bisogno, perché muoio ogni attimo, io, e rinasco nuovo e senza ricordi:
vivo e intero, non più in me, ma in ogni cosa fuori". (L. Pirandello)
La vaccinazione ha una scadenza, documentata in piu’ studi nonche’ dalle evidenze da Israele, alle porte della quarta pera, e con circa il 10% dei casi gravi rappresentato da vaccinati con terza dose.
L’aver avuto la malattia non si sa ancora per quanto possa proteggere, ma per certo e’ almeno un anno per la stragrandissima maggioranza, probabilmente di piu’ ma non lo sappiamo
Arrivera’ un momento in cui avremo numeri sulle reinfezioni, purtroppo non si possono escludere
ma dopo che ti sei reinfettato, va capito se prendi la malattia o meno.
E sara’ tutto da dimostrare.
I vaccini proteggono per qualche mese dalla malattia grave e dalla morte la maggioranza degli inoculati, una minoranza di under 16 maschi sani la manda per certo in ospedale, con un rapporto rischio/benefici schifoso.
Agli adulti puo’ salvare la vita, ma se non obblighi tutti gli adulti papabili a farlo continuiamo a favellare sul nulla
La vaccinazione ha una scadenza, documentata in piu’ studi nonche’ dalle evidenze da Israele, alle porte della quarta pera, e con circa il 10% dei casi gravi rappresentato da vaccinati con terza dose.
L’aver avuto la malattia non si sa ancora per quanto possa proteggere, ma per certo e’ almeno un anno per la stragrandissima maggioranza, probabilmente di piu’ ma non lo sappiamo
Quindi 9 mesi di green pass ci stanno tutti, no?
"Pensare alla morte, pregare. C'è pure chi ha ancora questo bisogno, e se ne fanno voce le campane.
Io non l'ho più questo bisogno, perché muoio ogni attimo, io, e rinasco nuovo e senza ricordi:
vivo e intero, non più in me, ma in ogni cosa fuori". (L. Pirandello)
Hanno esteso l'immunità di ulteriori 3 mesi per decreto...
Si può avere almeno 6 mesi di green pass se si hanno gli anticorpi no?
"Pensare alla morte, pregare. C'è pure chi ha ancora questo bisogno, e se ne fanno voce le campane.
Io non l'ho più questo bisogno, perché muoio ogni attimo, io, e rinasco nuovo e senza ricordi:
vivo e intero, non più in me, ma in ogni cosa fuori". (L. Pirandello)
Il green pass per un vaccinato che non abbia avuto la covid non dovrebbe durare oltre i 6 mesi in nessun caso (finche’ non si dirimera’ la questione sierologici)
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