Effectiveness of mRNA vaccines and waning of protection against SARS-CoV-2 infection and severe covid-19 during predominant circulation of the delta variant in Italy : retrospective cohort study

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OBJECTIVES: To estimate the effectiveness of mRNA vaccines against SARS-CoV-2 infection and severe covid-19 at different time after vaccination.

DESIGN: Retrospective cohort study.

SETTING: Italy, 27 December 2020 to 7 November 2021.

PARTICIPANTS: 33 250 344 people aged ≥16 years who received a first dose of BNT162b2 (Pfizer-BioNTech) or mRNA-1273 (Moderna) vaccine and did not have a previous diagnosis of SARS-CoV-2 infection.

MAIN OUTCOME MEASURES: SARS-CoV-2 infection and severe covid-19 (admission to hospital or death). Data were divided by weekly time intervals after vaccination. Incidence rate ratios at different time intervals were estimated by multilevel negative binomial models with robust variance estimator. Sex, age group, brand of vaccine, priority risk category, and regional weekly incidence in the general population were included as covariates. Geographic region was included as a random effect. Adjusted vaccine effectiveness was calculated as (1-IRR)×100, where IRR=incidence rate ratio, with the time interval 0-14 days after the first dose of vaccine as the reference.

RESULTS: During the epidemic phase when the delta variant was the predominant strain of the SARS-CoV-2 virus, vaccine effectiveness against SARS-CoV-2 infection significantly decreased (P<0.001) from 82% (95% confidence interval 80% to 84%) at 3-4 weeks after the second dose of vaccine to 33% (27% to 39%) at 27-30 weeks after the second dose. In the same time intervals, vaccine effectiveness against severe covid-19 also decreased (P<0.001), although to a lesser extent, from 96% (95% to 97%) to 80% (76% to 83%). High risk people (vaccine effectiveness -6%, -28% to 12%), those aged ≥80 years (11%, -15% to 31%), and those aged 60-79 years (2%, -11% to 14%) did not seem to be protected against infection at 27-30 weeks after the second dose of vaccine.

CONCLUSIONS: The results support the vaccination campaigns targeting high risk people, those aged ≥60 years, and healthcare workers to receive a booster dose of vaccine six months after the primary vaccination cycle. The results also suggest that timing the booster dose earlier than six months after the primary vaccination cycle and extending the offer of the booster dose to the wider eligible population might be warranted.

Medienart:

E-Artikel

Erscheinungsjahr:

2022

Erschienen:

2022

Enthalten in:

Zur Gesamtaufnahme - volume:376

Enthalten in:

BMJ (Clinical research ed.) - 376(2022) vom: 10. Feb., Seite e069052

Sprache:

Englisch

Beteiligte Personen:

Fabiani, Massimo [VerfasserIn]
Puopolo, Maria [VerfasserIn]
Morciano, Cristina [VerfasserIn]
Spuri, Matteo [VerfasserIn]
Spila Alegiani, Stefania [VerfasserIn]
Filia, Antonietta [VerfasserIn]
D'Ancona, Fortunato [VerfasserIn]
Del Manso, Martina [VerfasserIn]
Riccardo, Flavia [VerfasserIn]
Tallon, Marco [VerfasserIn]
Proietti, Valeria [VerfasserIn]
Sacco, Chiara [VerfasserIn]
Massari, Marco [VerfasserIn]
Da Cas, Roberto [VerfasserIn]
Mateo-Urdiales, Alberto [VerfasserIn]
Siddu, Andrea [VerfasserIn]
Battilomo, Serena [VerfasserIn]
Bella, Antonino [VerfasserIn]
Palamara, Anna Teresa [VerfasserIn]
Popoli, Patrizia [VerfasserIn]
Brusaferro, Silvio [VerfasserIn]
Rezza, Giovanni [VerfasserIn]
Menniti Ippolito, Francesca [VerfasserIn]
Pezzotti, Patrizio [VerfasserIn]
Italian Integrated Surveillance of covid-19 study group and Italian covid-19 Vaccines Registry group [VerfasserIn]
Boros, Stefano [Sonstige Person]
Rota, Maria Cristina [Sonstige Person]
Bressi, Marco [Sonstige Person]
Vescio, Maria Fenicia [Sonstige Person]
Petrone, Daniele [Sonstige Person]
Di Benedetto, Corrado [Sonstige Person]
Ciervo, Alessandra [Sonstige Person]
Stefanelli, Paola [Sonstige Person]
Petrucci, Antonia [Sonstige Person]
La Bianca, Michele [Sonstige Person]
Mignuoli, Anna Domenica [Sonstige Person]
Buono, Pietro [Sonstige Person]
Massimiliani, Erika [Sonstige Person]
Barbone, Fabio [Sonstige Person]
Vairo, Francesco [Sonstige Person]
Sticchi, Camilla [Sonstige Person]
Cereda, Danilo [Sonstige Person]
Di Furia, Lucia [Sonstige Person]
Sforza, Francesco [Sonstige Person]
Bassot, Annamaria [Sonstige Person]
Benetollo, Pier Paolo [Sonstige Person]
Pasqualini, Chiara [Sonstige Person]
Bisceglia, Lucia [Sonstige Person]
Palmas, Maria Antonietta [Sonstige Person]
Scondotto, Salvatore [Sonstige Person]
Balocchini, Emanuela [Sonstige Person]
Tosti, Anna [Sonstige Person]
Ruffier, Mauro [Sonstige Person]
Da Re, Filippo [Sonstige Person]
Odio, Camillo [Sonstige Person]
Recine, Michele [Sonstige Person]
Ruberto, Innocenza [Sonstige Person]
Bisogno, Salvatore Ascione Massimo [Sonstige Person]
Miserendino, Gandolfo [Sonstige Person]
Navacchia, Massimiliano [Sonstige Person]
Del Frate, Beatrice [Sonstige Person]
Cau, Emanuela [Sonstige Person]
Baiocchi, Diego [Sonstige Person]
Fusco, Danilo [Sonstige Person]
Gallo, Domenico [Sonstige Person]
Marchetti, Maria Rosa [Sonstige Person]
Spazzafumo, Liana [Sonstige Person]
Malatesta, Raffaele [Sonstige Person]
Fanolla, Antonio [Sonstige Person]
Conforti, Diego [Sonstige Person]
Trentini, Carlo [Sonstige Person]
Ruggeri, Antonino [Sonstige Person]
Ladalardo, Concetta [Sonstige Person]
Albano, Nehludoff [Sonstige Person]
Corona, Marco [Sonstige Person]
Lombardi, Paolo [Sonstige Person]
Iacono, Massimo [Sonstige Person]
Angori, Paolo Bruno [Sonstige Person]
Belardinelli, Andrea [Sonstige Person]
Solfiti, Milena [Sonstige Person]
Fioraso, Stefano [Sonstige Person]
Poma, Chiara [Sonstige Person]
Raccanello, Nadia [Sonstige Person]

Links:

Volltext

Themen:

2019-nCoV Vaccine mRNA-1273
BNT162 Vaccine
EPK39PL4R4
Journal Article
N38TVC63NU

Anmerkungen:

Date Completed 21.02.2022

Date Revised 21.02.2022

published: Electronic

Citation Status MEDLINE

doi:

10.1136/bmj-2021-069052

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM336771673