lancet-header

Preprints with The Lancet is part of SSRN´s First Look, a place where journals identify content of interest prior to publication. Authors have opted in at submission to The Lancet family of journals to post their preprints on Preprints with The Lancet. The usual SSRN checks and a Lancet-specific check for appropriateness and transparency have been applied. Preprints available here are not Lancet publications or necessarily under review with a Lancet journal. These preprints are early stage research papers that have not been peer-reviewed. The findings should not be used for clinical or public health decision making and should not be presented to a lay audience without highlighting that they are preliminary and have not been peer-reviewed. For more information on this collaboration, see the comments published in The Lancet about the trial period, and our decision to make this a permanent offering, or visit The Lancet´s FAQ page, and for any feedback please contact preprints@lancet.com.

Comparative COVID-19 Vaccines Effectiveness in Preventing Infections, Hospitalizations, and Deaths with SARS-CoV-2 BA.5 and Ba.2 Omicron Lineages: A Case-Case and Cohort Study Using Electronic Health Records in Portugal

16 Pages Posted: 3 Aug 2022

See all articles by Irina Kislaya

Irina Kislaya

National Health Institute Doutor Ricardo Jorge (INSA) - Epidemiology Department

Pedro Casaca

Directorate of Information and Analysis Services

Vítor Borges

National Health Institute Doutor Ricardo Jorge (INSA) - Bioinformatics Unit

Carlos Sousa

Unilabs

Bibiana I. Ferreira

Algarve Biomedical Center Research Institute (ABC-RI)

Ana Fonte

affiliation not provided to SSRN

Eugenia Fernandes

Directorate of Information and Analysis Services

Carlos Matias Dias

affiliation not provided to SSRN

Silvia Duarte

National Health Institute Doutor Ricardo Jorge (INSA) - Innovation and Technology Unit

José Pedro Almeida

Unilabs

Inês Grenho

affiliation not provided to SSRN

Luís Coelho

affiliation not provided to SSRN

Rita Ferreira

National Health Institute Doutor Ricardo Jorge (INSA) - Bioinformatics Unit

Patrícia Pita Ferreira

affiliation not provided to SSRN

Cláudia Medeiros Borges

Administração Central do Sistema de Saúde, I.P.

Joana Isidro

National Health Institute Doutor Ricardo Jorge (INSA) - Bioinformatics Unit

Miguel Pinto

National Health Institute Doutor Ricardo Jorge (INSA) - Bioinformatics Unit

Luís Menezes

Unilabs

Daniel Sobral

affiliation not provided to SSRN

Alexandra Nunes

affiliation not provided to SSRN

Daniela Santos

affiliation not provided to SSRN

António Maia Gonçalves

affiliation not provided to SSRN

Luís Vieira

National Health Institute Doutor Ricardo Jorge (INSA) - Innovation and Technology Unit

João Paulo Gomes

National Health Institute Doutor Ricardo Jorge (INSA) - Innovation and Technology Unit

Pedro Pinto Leite

Directorate of Information and Analysis Services

Baltazar Nunes

New University of Lisbon - NOVA National School of Public Health

Ausenda Machado

affiliation not provided to SSRN

André Peralta-Santos

Directorate of Information and Analysis Services

More...

Abstract

Background: In the context of a highly vaccinated population and multiple Omicron lineages circulation, it is relevant to clarify the effect of vaccination and previous infections on the risk of infection and severe post-infection outcomes. This study aimed to measure the comparative vaccine effectiveness of primary and booster vaccination between Omicron BA.5 and BA.2 lineages against infection and compare lineage-specific post-infection vaccine effectiveness against COVID-19-related hospitalization and mortality.

Methods: Using electronic health records and SARS-CoV-2 laboratory surveillance data, we conducted a case-case and a cohort study covering the period of Omicron BA.2/BA.5 lineage replacement in Portugal (April 25 and June 10, 2022). Variant classification was performed through whole-genome sequencing or Spike Gene Target Failure.

Findings: From a total of 27,702 samples, 55.5% were classified as BA.2 and the remaining as BA.5. We observed no evidence of reduced vaccine effectiveness from either the primary vaccination (OR=1.07, 95%CI:0.93-1.23) or booster dose (OR=0.96, 95%CI:0.84-1.09) against BA.5 infection compared with BA.2. Higher odds of previous infection were observed in BA.5 cases compared with BA.2 (OR=1.44; 95%CI:1.30-1.60). Among those infected with BA.5, booster post-infection vaccine effectiveness was 77% (95%CI:49-90%) and 88% (95%CI:70-96%) against COVID-19 hospitalization and death, respectively, while among BA.2 cases, booster post-infection vaccine effectiveness was 93% (95%CI:86-97%) and 94% (95%CI:76-99%), respectively.

Interpretation: This study shows that the SARS-CoV-2 Omicron BA.5 lineage was associated with higher odds of previous infection compared with Omicron BA.2. Although less effective compared with BA.2, COVID-19 booster vaccination still offers substantial post-infection protection against severe outcomes following BA.5 infection.

Funding Information: The acquisition of sequencing equipment/reagents used in this study by INSA was partially funded by the HERA project (Grant/2021/PHF/23776) supported by the European Commission through the European Centre for Disease Control, and also partially funded by the GenomePT project (POCI-01-0145-FEDER-022184), supported by COMPETE 2020 – Operational Programme for Competitiveness and Internationalisation (POCI), Lisboa Portugal Regional Operational Programme (Lisboa2020), Algarve Portugal Regional Operational Programme (CRESC Algarve2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF), and by the Portuguese Science and Technology Foundation (FCT).

Declaration of Interests: None.

Ethics Approval Statement: The genomic surveillance of SARS-CoV-2 in Portugal is regulated by the Assistant Secretary of State and Health Executive Order (Despacho n. º 331/2021 of January 11, 2021). The study protocol received the clearance of the Ethics Committee of INSA on June 15, 2022.

Keywords: COVID-19, relative vaccine effectiveness, post-infection vaccine effectiveness, BA5, BA2

Suggested Citation

Kislaya, Irina and Casaca, Pedro and Borges, Vítor and Sousa, Carlos and Ferreira, Bibiana I. and Fonte, Ana and Fernandes, Eugenia and Matias Dias, Carlos and Duarte, Silvia and Almeida, José Pedro and Grenho, Inês and Coelho, Luís and Ferreira, Rita and Pita Ferreira, Patrícia and Borges, Cláudia Medeiros and Isidro, Joana and Pinto, Miguel and Menezes, Luís and Sobral, Daniel and Nunes, Alexandra and Santos, Daniela and Maia Gonçalves, António and Vieira, Luís and Gomes, João Paulo and Leite, Pedro Pinto and Nunes, Baltazar and Machado, Ausenda and Peralta-Santos, André, Comparative COVID-19 Vaccines Effectiveness in Preventing Infections, Hospitalizations, and Deaths with SARS-CoV-2 BA.5 and Ba.2 Omicron Lineages: A Case-Case and Cohort Study Using Electronic Health Records in Portugal. Available at SSRN: https://ssrn.com/abstract=4180482 or http://dx.doi.org/10.2139/ssrn.4180482

Irina Kislaya (Contact Author)

National Health Institute Doutor Ricardo Jorge (INSA) - Epidemiology Department ( email )

Lisbon
Portugal

Pedro Casaca

Directorate of Information and Analysis Services ( email )

Lisboa
Portugal

Vítor Borges

National Health Institute Doutor Ricardo Jorge (INSA) - Bioinformatics Unit ( email )

Portugal

Carlos Sousa

Unilabs ( email )

Porto
Portugal

Bibiana I. Ferreira

Algarve Biomedical Center Research Institute (ABC-RI) ( email )

Faro
Portugal

Ana Fonte

affiliation not provided to SSRN ( email )

No Address Available

Eugenia Fernandes

Directorate of Information and Analysis Services ( email )

Lisboa
Portugal

Carlos Matias Dias

affiliation not provided to SSRN ( email )

No Address Available

Silvia Duarte

National Health Institute Doutor Ricardo Jorge (INSA) - Innovation and Technology Unit ( email )

Lisbon
Portugal

José Pedro Almeida

Unilabs ( email )

Porto
Portugal

Inês Grenho

affiliation not provided to SSRN ( email )

No Address Available

Luís Coelho

affiliation not provided to SSRN ( email )

No Address Available

Rita Ferreira

National Health Institute Doutor Ricardo Jorge (INSA) - Bioinformatics Unit ( email )

Portugal

Patrícia Pita Ferreira

affiliation not provided to SSRN ( email )

No Address Available

Cláudia Medeiros Borges

Administração Central do Sistema de Saúde, I.P. ( email )

Portugal

Joana Isidro

National Health Institute Doutor Ricardo Jorge (INSA) - Bioinformatics Unit ( email )

Portugal

Miguel Pinto

National Health Institute Doutor Ricardo Jorge (INSA) - Bioinformatics Unit ( email )

Portugal

Luís Menezes

Unilabs ( email )

Porto
Portugal

Daniel Sobral

affiliation not provided to SSRN ( email )

No Address Available

Alexandra Nunes

affiliation not provided to SSRN ( email )

No Address Available

Daniela Santos

affiliation not provided to SSRN ( email )

No Address Available

António Maia Gonçalves

affiliation not provided to SSRN ( email )

No Address Available

Luís Vieira

National Health Institute Doutor Ricardo Jorge (INSA) - Innovation and Technology Unit ( email )

Lisbon
Portugal

João Paulo Gomes

National Health Institute Doutor Ricardo Jorge (INSA) - Innovation and Technology Unit ( email )

Lisbon
Portugal

Pedro Pinto Leite

Directorate of Information and Analysis Services ( email )

Lisboa
Portugal

Baltazar Nunes

New University of Lisbon - NOVA National School of Public Health ( email )

Lisbon
Portugal

Ausenda Machado

affiliation not provided to SSRN ( email )

No Address Available

André Peralta-Santos

Directorate of Information and Analysis Services ( email )

Lisboa
Portugal

Click here to go to TheLancet.com

Paper statistics

Abstract Views
2,221
Downloads
526
PlumX Metrics