Effectiveness of ChAdOx1 vaccine in older adults during SARS-CoV-2 Gamma variant circulation in São Paulo

Hitchings, Matt D T; Ranzani, Otávio T.; Dorion, Murilo; D’Agostini, Tatiana Lang; Paula, Regiane Cardoso de; Paula, Olívia Ferreira Pereira de; Villela, Edlaine Faria de Moura; Torres, Mario S.; Oliveira, Silvano Barbosa de; Schulz, Wade L.; Almirón, María; Said, Rodrigo Fabiano do Carmo; Oliveira, Roberto Dias de; Silva, Patrícia Vieira; Araújo, Wildo Navegantes de; Gorinchteyn, Jean Carlo; Andrews, Jason R; Cummings, Derek A. T.; Ko, Albert I.; Croda, Júlio

doi:10.1038/s41467-021-26459-6

Cited by 73 publications

(69 citation statements)

References 31 publications

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“…Our estimates are in accordance with studies of ChAdOx1 effectiveness in the context of Gamma/Delta[ 14 , 15 ]. We observed VE increased up to 53.2% during 42-55 days of the first dose[ 14 ], and decreased afterwards in those that did not take the second dose. It is not clear the reason for the decrease in effectiveness.…”

Section: Discussionsupporting

confidence: 91%

“…We could not evaluate VE against COVID-19 severity. Although the test-negative design can deal with important confounding factors, such as health-seeking behaviour, we cannot rule out residual confounding for other factors (e.g., infection risk exposure)[ 12 , 13 , 14 ]. Finally, the estimates might not be generalizable to the entire population because we analysed only tested individuals[ 12 , 13 , 14 ].…”

Section: Discussionmentioning

confidence: 99%

“…We linked the community-program testing database with the vaccination campaign database. Overall, we followed the methodology reported elsewhere [ 12 , 13 , 14 ]. Briefly, we selected all RT-qPCR (positive and negative tests) from symptomatic individuals, defined as presenting at least one symptom, from RT-qPCRs sampled within 10 days of symptoms onset[ 13 ].…”

Section: Methodsmentioning

confidence: 99%

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Vaccine effectiveness of ChAdOx1 nCoV-19 against COVID-19 in a socially vulnerable community in Rio de Janeiro, Brazil: a test-negative design study

Ranzani

Silva

Peres

et al. 2022

Clinical Microbiology and Infection

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Objectives To estimate the vaccine effectiveness after first and second dose of ChAdOx1 nCoV-19 against symptomatic COVID-19 and infection in a socially vulnerable community in Brazil when Gamma and Delta were the predominant variants circulating. Methods We conducted a test-negative study at the community “Complexo da Maré”, the largest group of slums (n=16) in Rio de Janeiro, Brazil, from Jan 17, 2021 to Nov 27, 2021. We selected RT-qPCR positive and negative tests from a broad community testing program. The primary outcome was symptomatic COVID-19 (positive RT-qPCR with at least 1 symptom) and the secondary outcome was infection (any positive RT-qPCR). Vaccine effectiveness was estimated as 1 – OR, which was obtained from adjusted logistic regression models. Results We included 10,077 RT-qPCR tests (6,394, 64% from symptomatic and 3,683, 36% from asymptomatic individuals). The mean age was 40 (SD: 14) years and the median time between vaccination and RT-qPCR testing among vaccinated was 41 [p25-p75: 21-62] days for the first dose and 36 [p25-p75: 17-59] days for the second dose. Adjusted vaccine effectiveness against symptomatic COVID-19 was 31.6% (95% CI, 12.0-46.8) after 21 days of first dose and 65.1% (95% CI, 40.9-79.4) after 14 days of second dose. Adjusted vaccine effectiveness against COVID-19 infection was 31.0% (95% CI, 12.7-45.5) after 21 days of first dose and 59.0% (95% CI, 33.1-74.8) after 14 days of second dose. Conclusions ChAdOx1 nCoV-19 was effective on reducing symptomatic COVID-19 in a socially vulnerable community in Brazil when Gamma and Delta were the predominant variants circulating.

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Section: Discussionsupporting

confidence: 91%

Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

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Vaccine effectiveness of ChAdOx1 nCoV-19 against COVID-19 in a socially vulnerable community in Rio de Janeiro, Brazil: a test-negative design study

Ranzani

Silva

Peres

et al. 2022

Clinical Microbiology and Infection

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“…In a case–control study with 60 000 elderly participants in São Paulo State/Brazil, researchers determined the VE of the AZ vaccine during a period of dominant infections with the gamma variant virus. VE was 78% against symptomatic COVID‐19, 88% against hospitalization and 94% against death associated with SARS‐CoV‐2 (Hitchings et al ., 2021 ).…”

Section: The Limits Of Vaccination Against Infection and Transmissionmentioning

confidence: 99%

Can a combination of vaccination and face mask wearing contain the COVID‐19 pandemic?

Brüssow

Zuber

2021

Microbial Biotechnology

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Summary The COVID‐19 pandemic is going into its third year with Europe again being the focus of major epidemic activity. The present review tries to answer the question whether one can come to grip with the pandemic by a combination of vaccinations and non‐pharmaceutical interventions (NPIs). Several COVID‐19 vaccines are of remarkable efficacy and achieve high protection rates against symptomatic disease, especially severe disease, but mathematical models suggest that the current vaccination coverage in many countries is insufficient to achieve pandemic control. NPIs are needed as complementary measures because recent research has also revealed the limits of vaccination alone. Here, we review the evidence for efficacy of face mask wearing in various settings. Overall pooled analysis showed significant reduction in COVID‐19 incidence with mask wearing, although heterogeneity between studies was substantial. Controlled trials of mask wearing are difficult to conduct, separating mask wearing effects in population studies from the impact of other NPIs is challenging and the efficacy of masks depend on mask material and mask fit. The combination of vaccination and mask wearing is potentially synergistic since vaccination protects so far well from disease development (the omicron variant is currently an unknown) but immunity from infection wanes over few months after vaccination. In comparison, masks interfere with the virus transmission process at a level of a physical barrier independent of coronavirus variant. Vaccination and masks are much less costly to apply than other NPI measures which are associated with high economic and social costs, but paradoxically both measures are the target of a vocal opposition by a sizable minority of the society. In parallel with biomedical research, we need more social science research into this opposition to guide political decisions on how to end the pandemic.

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“…1.351) and Gamma (P.1) were identified in South Africa and Japan/Brazil, respectively (2)(3)(4). Both Beta and Gamma increased concerns because they decreased efficacy of several vaccines in clinical trials (4)(5)(6)(7)(8)(9)(10).…”

Section: Introductionmentioning

confidence: 99%

SARS-CoV-2 Delta variant induces enhanced pathology and inflammatory responses in K18-hACE2 mice

Lee

Wong

Russ

et al. 2022

Preprint

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The COVID-19 pandemic has been fueled by novel variants of concern (VOC) that have increased transmissibility, receptor binding affinity, and other properties that enhance disease. The goal of this study is to characterize unique pathogenesis of the Delta VOC strain in the K18-hACE2-mouse challenge model. Challenge studies suggested that the lethal dose of Delta was higher than Alpha or Beta strains. To characterize the differences in the Delta strain’s pathogenesis, a time-course experiment was performed to evaluate the overall host response to Alpha or Delta variant challenge. qRT-PCR analysis of Alpha- or Delta- challenged mice revealed no significant difference between viral RNA burden in the lung, nasal wash or brain. However, histopathological analysis revealed high lung tissue inflammation and cell infiltration following Delta- but not Alpha-challenge at day 6. Additionally, pro-inflammatory cytokines were highest at day 6 in Delta-challenged mice suggesting enhanced pneumonia. Total RNA-sequencing analysis of lungs comparing infected to uninfected mice revealed that Alpha-challenged mice have more total genes differentially activated, conversely, Delta-challenged mice have a higher magnitude of differential gene expression. Delta-challenged mice have increased interferon-dependent gene expression and IFN-γ production compared to Alpha. Analysis of TCR clonotypes suggested that Delta challenged mice have increased T-cell infiltration compared to Alpha challenged. Our data suggest that Delta has evolved to engage interferon responses in a manner that may enhance pathogenesis. The in vivo and in silico observations of this study underscore the need to conduct experiments with VOC strains to best model COVID-19 when evaluating therapeutics and vaccines.

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Effectiveness of ChAdOx1 vaccine in older adults during SARS-CoV-2 Gamma variant circulation in São Paulo

Cited by 73 publications

References 31 publications

Vaccine effectiveness of ChAdOx1 nCoV-19 against COVID-19 in a socially vulnerable community in Rio de Janeiro, Brazil: a test-negative design study

Vaccine effectiveness of ChAdOx1 nCoV-19 against COVID-19 in a socially vulnerable community in Rio de Janeiro, Brazil: a test-negative design study

Can a combination of vaccination and face mask wearing contain the COVID‐19 pandemic?

SARS-CoV-2 Delta variant induces enhanced pathology and inflammatory responses in K18-hACE2 mice

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