Portal de Periódicos da CAPES

Carta Acesso aberto Produção Nacional Revisado por pares

BIBTEX RIS

Vaccine effectiveness of ChAdOx1 nCoV-19 against COVID-19 in a socially vulnerable community in Rio de Janeiro, Brazil: author's response

2022; Elsevier BV; Volume: 28; Issue: 8 Linguagem: Inglês

10.1016/j.cmi.2022.03.037

1469-0691

Otávio T. Ranzani, Fernando A. Bozza,

Immune responses and vaccinations

We appreciate the interest in our publication [[1]Zeng G. Re: vaccine effectiveness of ChAdOx1 nCoV-19 against COVID-19 in a socially vulnerable community in Rio de Janeiro, Brazil by Ranzani et al.Clin Microbiol Infect. 2022; 28: 1165https://doi.org/10.1016/j.cmi.2022.03.008Abstract Full Text Full Text PDF Scopus (1) Google Scholar,[2]Ranzani O.T. Silva A.A.B. Peres I.T. Antunes B.B.P. Gonzaga-da-Silva T.W. Soranz D.R. et al.Vaccine effectiveness of ChAdOx1 nCoV-19 against COVID-19 in a socially vulnerable community in Rio de Janeiro, Brazil: a test-negative design study.Clin Microbiol Infect. 2022; 28: 736e.1-736e.4https://doi.org/10.1016/j.cmi.2022.01.032Abstract Full Text Full Text PDF Scopus (5) Google Scholar]. First, we would like to highlight that our study followed a pre-specified protocol, which was based on other protocols for evaluation of COVID-19 vaccine effectiveness applying case-control, test-negative study design conducted in Brazil and in accordance with the World Health Organization (WHO) recommendations [[3]Ranzani O.T. Hitchings M.D.T. Dorion M. D'Agostini T.L. de Paula R.C. de Paula O.F.P. et al.Effectiveness of the CoronaVac vaccine in older adults during a gamma variant associated epidemic of COVID-19 in Brazil: test negative case-control study.BMJ. 2021; 374: n2015https://doi.org/10.1136/bmj.n2015Crossref PubMed Scopus (97) Google Scholar,[4]Patel M.K. Bergeri I. Bresee J.S. Cowling B.J. Crowcroft N.S. Fahmy K. et al.Evaluation of post-introduction COVID-19 vaccine effectiveness: summary of interim guidance of the World Health Organization.Vaccine. 2021; 39: 4013-4024https://doi.org/10.1016/j.vaccine.2021.05.099Crossref PubMed Scopus (40) Google Scholar].Regarding the decrease in effectiveness following the first dose, the change overtime for the first dose is shown in Table 1 of the original article [[2]Ranzani O.T. Silva A.A.B. Peres I.T. Antunes B.B.P. Gonzaga-da-Silva T.W. Soranz D.R. et al.Vaccine effectiveness of ChAdOx1 nCoV-19 against COVID-19 in a socially vulnerable community in Rio de Janeiro, Brazil: a test-negative design study.Clin Microbiol Infect. 2022; 28: 736e.1-736e.4https://doi.org/10.1016/j.cmi.2022.01.032Abstract Full Text Full Text PDF Scopus (5) Google Scholar]. We did not evaluate change overtime for the second dose because we had not sample size/power to conduct this analysis. As stated in our discussion, the observed decrease overtime for the first dose can be attributed to some reasons. For instance, waning, which is the natural decline of protection, as well as the surge of the Delta variant. Because we do not have data on sequencing, we cannot disentangle this issue further, as well as we cannot obtain an estimate for protection against Gamma and Delta variants.We agree that evaluation of effectiveness by age is important [[3]Ranzani O.T. Hitchings M.D.T. Dorion M. D'Agostini T.L. de Paula R.C. de Paula O.F.P. et al.Effectiveness of the CoronaVac vaccine in older adults during a gamma variant associated epidemic of COVID-19 in Brazil: test negative case-control study.BMJ. 2021; 374: n2015https://doi.org/10.1136/bmj.n2015Crossref PubMed Scopus (97) Google Scholar], but we pre-specified that we would conduct this analysis by the median age. Subgroup analysis could lead to spurious findings if not pre-specified. We have very few elderlies recruited in the study because of the age distribution of the analysed population in "Complexo da Maré." Finally, our study population comprises only adults, and children were not even receiving COVID-19 vaccines at the time of study, therefore it would be impossible to estimate direct vaccine effectiveness in children.Regarding potential confounding factors, we excluded previous infected individuals (eFigure 3, supplementary material of the original article [[2]Ranzani O.T. Silva A.A.B. Peres I.T. Antunes B.B.P. Gonzaga-da-Silva T.W. Soranz D.R. et al.Vaccine effectiveness of ChAdOx1 nCoV-19 against COVID-19 in a socially vulnerable community in Rio de Janeiro, Brazil: a test-negative design study.Clin Microbiol Infect. 2022; 28: 736e.1-736e.4https://doi.org/10.1016/j.cmi.2022.01.032Abstract Full Text Full Text PDF Scopus (5) Google Scholar]). We agree that personal behaviour could affect the risk of infection, and if this behaviour is different between vaccinated individuals compared to unvaccinated individuals, we could have residual confounding, as acknowledged in the article [[2]Ranzani O.T. Silva A.A.B. Peres I.T. Antunes B.B.P. Gonzaga-da-Silva T.W. Soranz D.R. et al.Vaccine effectiveness of ChAdOx1 nCoV-19 against COVID-19 in a socially vulnerable community in Rio de Janeiro, Brazil: a test-negative design study.Clin Microbiol Infect. 2022; 28: 736e.1-736e.4https://doi.org/10.1016/j.cmi.2022.01.032Abstract Full Text Full Text PDF Scopus (5) Google Scholar]. However, as also discussed in the manuscript, our indicator bias did not indicate any remarkable bias, under the assumption of a case-control, test-negative design [[5]Hitchings M.D.T. Lewnard J.A. Dean N.E. Ko A.I. Ranzani O.T. Andrews J.R. et al.Use of recently vaccinated individuals to detect bias in test-negative case-control studies of COVID-19 vaccine effectiveness.Epidemiology. 2022; 33: 450-456https://doi.org/10.1101/2021.06.23.21259415Crossref Scopus (0) Google Scholar]. We agree cross-protection could influence on vaccine effectiveness estimates if those tested negative individuals were symptomatic by some virus with cross-protection, however this is still a hypothesis for COVID-19 vaccines.We would like to highlight that our vaccine estimates were in accordance to previous literature and robust to several sensitivity analyses, as shown in the supplementary material of the original article [[2]Ranzani O.T. Silva A.A.B. Peres I.T. Antunes B.B.P. Gonzaga-da-Silva T.W. Soranz D.R. et al.Vaccine effectiveness of ChAdOx1 nCoV-19 against COVID-19 in a socially vulnerable community in Rio de Janeiro, Brazil: a test-negative design study.Clin Microbiol Infect. 2022; 28: 736e.1-736e.4https://doi.org/10.1016/j.cmi.2022.01.032Abstract Full Text Full Text PDF Scopus (5) Google Scholar].Transparency declarationThis work is part of the Grand Challenges International COVID-19 Data Alliance (ICODA) pilot initiative, delivered by Health Data Research UK and funded by the Bill & Melinda Gates Foundation and the Minderoo Foundation . This study was also supported by the National Council for Scientific and Technological Development and Carlos Chagas Filho Foundation for Research Support of the State of Rio de Janeiro. OTR is funded by a Sara Borrell grant from the Instituto de Salud Carlos III (CD19/ 00110). All authors reported no conflicts. All authors conducted the research independently of the funding bodies. The findings and conclusions of this article reflect the opinions of the authors and not those of the funding bodies or other affiliations of the authors.Author contributionsOTR and FAB equally contributed to this study. We appreciate the interest in our publication [[1]Zeng G. Re: vaccine effectiveness of ChAdOx1 nCoV-19 against COVID-19 in a socially vulnerable community in Rio de Janeiro, Brazil by Ranzani et al.Clin Microbiol Infect. 2022; 28: 1165https://doi.org/10.1016/j.cmi.2022.03.008Abstract Full Text Full Text PDF Scopus (1) Google Scholar,[2]Ranzani O.T. Silva A.A.B. Peres I.T. Antunes B.B.P. Gonzaga-da-Silva T.W. Soranz D.R. et al.Vaccine effectiveness of ChAdOx1 nCoV-19 against COVID-19 in a socially vulnerable community in Rio de Janeiro, Brazil: a test-negative design study.Clin Microbiol Infect. 2022; 28: 736e.1-736e.4https://doi.org/10.1016/j.cmi.2022.01.032Abstract Full Text Full Text PDF Scopus (5) Google Scholar]. First, we would like to highlight that our study followed a pre-specified protocol, which was based on other protocols for evaluation of COVID-19 vaccine effectiveness applying case-control, test-negative study design conducted in Brazil and in accordance with the World Health Organization (WHO) recommendations [[3]Ranzani O.T. Hitchings M.D.T. Dorion M. D'Agostini T.L. de Paula R.C. de Paula O.F.P. et al.Effectiveness of the CoronaVac vaccine in older adults during a gamma variant associated epidemic of COVID-19 in Brazil: test negative case-control study.BMJ. 2021; 374: n2015https://doi.org/10.1136/bmj.n2015Crossref PubMed Scopus (97) Google Scholar,[4]Patel M.K. Bergeri I. Bresee J.S. Cowling B.J. Crowcroft N.S. Fahmy K. et al.Evaluation of post-introduction COVID-19 vaccine effectiveness: summary of interim guidance of the World Health Organization.Vaccine. 2021; 39: 4013-4024https://doi.org/10.1016/j.vaccine.2021.05.099Crossref PubMed Scopus (40) Google Scholar]. Regarding the decrease in effectiveness following the first dose, the change overtime for the first dose is shown in Table 1 of the original article [[2]Ranzani O.T. Silva A.A.B. Peres I.T. Antunes B.B.P. Gonzaga-da-Silva T.W. Soranz D.R. et al.Vaccine effectiveness of ChAdOx1 nCoV-19 against COVID-19 in a socially vulnerable community in Rio de Janeiro, Brazil: a test-negative design study.Clin Microbiol Infect. 2022; 28: 736e.1-736e.4https://doi.org/10.1016/j.cmi.2022.01.032Abstract Full Text Full Text PDF Scopus (5) Google Scholar]. We did not evaluate change overtime for the second dose because we had not sample size/power to conduct this analysis. As stated in our discussion, the observed decrease overtime for the first dose can be attributed to some reasons. For instance, waning, which is the natural decline of protection, as well as the surge of the Delta variant. Because we do not have data on sequencing, we cannot disentangle this issue further, as well as we cannot obtain an estimate for protection against Gamma and Delta variants. We agree that evaluation of effectiveness by age is important [[3]Ranzani O.T. Hitchings M.D.T. Dorion M. D'Agostini T.L. de Paula R.C. de Paula O.F.P. et al.Effectiveness of the CoronaVac vaccine in older adults during a gamma variant associated epidemic of COVID-19 in Brazil: test negative case-control study.BMJ. 2021; 374: n2015https://doi.org/10.1136/bmj.n2015Crossref PubMed Scopus (97) Google Scholar], but we pre-specified that we would conduct this analysis by the median age. Subgroup analysis could lead to spurious findings if not pre-specified. We have very few elderlies recruited in the study because of the age distribution of the analysed population in "Complexo da Maré." Finally, our study population comprises only adults, and children were not even receiving COVID-19 vaccines at the time of study, therefore it would be impossible to estimate direct vaccine effectiveness in children. Regarding potential confounding factors, we excluded previous infected individuals (eFigure 3, supplementary material of the original article [[2]Ranzani O.T. Silva A.A.B. Peres I.T. Antunes B.B.P. Gonzaga-da-Silva T.W. Soranz D.R. et al.Vaccine effectiveness of ChAdOx1 nCoV-19 against COVID-19 in a socially vulnerable community in Rio de Janeiro, Brazil: a test-negative design study.Clin Microbiol Infect. 2022; 28: 736e.1-736e.4https://doi.org/10.1016/j.cmi.2022.01.032Abstract Full Text Full Text PDF Scopus (5) Google Scholar]). We agree that personal behaviour could affect the risk of infection, and if this behaviour is different between vaccinated individuals compared to unvaccinated individuals, we could have residual confounding, as acknowledged in the article [[2]Ranzani O.T. Silva A.A.B. Peres I.T. Antunes B.B.P. Gonzaga-da-Silva T.W. Soranz D.R. et al.Vaccine effectiveness of ChAdOx1 nCoV-19 against COVID-19 in a socially vulnerable community in Rio de Janeiro, Brazil: a test-negative design study.Clin Microbiol Infect. 2022; 28: 736e.1-736e.4https://doi.org/10.1016/j.cmi.2022.01.032Abstract Full Text Full Text PDF Scopus (5) Google Scholar]. However, as also discussed in the manuscript, our indicator bias did not indicate any remarkable bias, under the assumption of a case-control, test-negative design [[5]Hitchings M.D.T. Lewnard J.A. Dean N.E. Ko A.I. Ranzani O.T. Andrews J.R. et al.Use of recently vaccinated individuals to detect bias in test-negative case-control studies of COVID-19 vaccine effectiveness.Epidemiology. 2022; 33: 450-456https://doi.org/10.1101/2021.06.23.21259415Crossref Scopus (0) Google Scholar]. We agree cross-protection could influence on vaccine effectiveness estimates if those tested negative individuals were symptomatic by some virus with cross-protection, however this is still a hypothesis for COVID-19 vaccines. We would like to highlight that our vaccine estimates were in accordance to previous literature and robust to several sensitivity analyses, as shown in the supplementary material of the original article [[2]Ranzani O.T. Silva A.A.B. Peres I.T. Antunes B.B.P. Gonzaga-da-Silva T.W. Soranz D.R. et al.Vaccine effectiveness of ChAdOx1 nCoV-19 against COVID-19 in a socially vulnerable community in Rio de Janeiro, Brazil: a test-negative design study.Clin Microbiol Infect. 2022; 28: 736e.1-736e.4https://doi.org/10.1016/j.cmi.2022.01.032Abstract Full Text Full Text PDF Scopus (5) Google Scholar]. Transparency declarationThis work is part of the Grand Challenges International COVID-19 Data Alliance (ICODA) pilot initiative, delivered by Health Data Research UK and funded by the Bill & Melinda Gates Foundation and the Minderoo Foundation . This study was also supported by the National Council for Scientific and Technological Development and Carlos Chagas Filho Foundation for Research Support of the State of Rio de Janeiro. OTR is funded by a Sara Borrell grant from the Instituto de Salud Carlos III (CD19/ 00110). All authors reported no conflicts. All authors conducted the research independently of the funding bodies. The findings and conclusions of this article reflect the opinions of the authors and not those of the funding bodies or other affiliations of the authors. This work is part of the Grand Challenges International COVID-19 Data Alliance (ICODA) pilot initiative, delivered by Health Data Research UK and funded by the Bill & Melinda Gates Foundation and the Minderoo Foundation . This study was also supported by the National Council for Scientific and Technological Development and Carlos Chagas Filho Foundation for Research Support of the State of Rio de Janeiro. OTR is funded by a Sara Borrell grant from the Instituto de Salud Carlos III (CD19/ 00110). All authors reported no conflicts. All authors conducted the research independently of the funding bodies. The findings and conclusions of this article reflect the opinions of the authors and not those of the funding bodies or other affiliations of the authors. Author contributionsOTR and FAB equally contributed to this study. OTR and FAB equally contributed to this study. The authors thank the Redes da Mare for all their support and the efficient strategies on community engagement and communication during the pandemic, as well as the Unidade de Apoio ao Diagno_stico da COVID-19 for their support on the testing diagnosis. OTR acknowledges support from the Spanish Ministry of Science and Innovation and State Research Agency through the " Centro de Excelencia Severo Ochoa 2019e2023 " Program (CEX2018- 000806-S) and from the Generalitat de Catalunya through the CERCA Program . In addition, the authors thank the Center for Healthcare Operations and Intelligence research group for their discussions and collaborative production of scientific analyses of the COVID-19 pandemic in Brazil. Re: Vaccine effectiveness of ChAdOx1 nCoV-19 against COVID-19 in a socially vulnerable community in Rio de Janeiro, Brazil by Ranzani et al.Clinical Microbiology and InfectionVol. 28Issue 8PreviewRanzani et al. evaluated the effectiveness of ChAdOx1 NCOV-19 against COVID-19 in a socially vulnerable community and observed that vaccine effectiveness increased up to 53.2% during 42–55 days after the first dose, and decreased afterwards in those who did not take the second dose [1]. They hypothesized that this decrease might occur in part because of an increase in Delta dominance and waning of immune Response. I think it is more likely that the vaccine's immune protection declines over time, and the time-dependent decline is greater than the mutation-related decline [2]. Full-Text PDF