Single-dose BNT162b2 vaccine protects against asymptomatic SARS-CoV-2 infection

Weekes, Michael P.; Jones, Nick K; Rivett, Lucy; Workman, Christopher T.; Ferris, Mark; Shaw, Ashley; Lehner, Paul J.; Howes, Rob; Wright, Giles; Matheson, Nicholas J

doi:10.22541/au.161420511.12987747/v1

Cited by 20 publications

(20 citation statements)

References 2 publications

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“…As with any modelling study, there are several limitations to our approach. First, while phase III trial efficacy results have been announced for several vaccine candidates, durability data are not yet available, and data on the extent to which the current vaccine products can prevent infection are still emerging 2,3,28 ; our model assumptions may therefore need to be updated as trials and effectiveness studies progress. Second, the number of doses and the timing of their availability are also uncertain; for this reason, we have illustrated simplified scenarios in which vaccination occurs over a one-month period for a range of epidemic stages.…”

Section: Discussionmentioning

confidence: 99%

“…Trial results to date indicate higher protection against severe COVID-19 disease, and this is supported by evidence being generated by vaccine implementation in the UK and Israel 3,5,[24][25][26][27] . The extent to which these candidate vaccines will prevent infection is not fully known, however the phase III Oxford/AstraZeneca study reported efficacy against asymptomatic COVID-19 of 27.3% (95% CI −17.2-54.9) in a preliminary analysis 2 , and evidence from the UK indicates a four-fold reduction in asymptomatic COVID-19 in vaccinated versus unvaccinated healthcare workers, following a single dose of the Pfizer/BioNTech vaccine 28 . Given these results, for our baseline simulations we assume vaccine efficacy against infection of 90%, with an additional 60% efficacy against severe disease for vaccinated individuals who experience breakthrough infection 24 .…”

Section: Parameterisationmentioning

confidence: 99%

See 1 more Smart Citation

Within-country age-based prioritisation, global allocation, and public health impact of a vaccine against SARS-CoV-2: A mathematical modelling analysis

Hogan

Winskill

Watson

et al. 2021

Vaccine

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The worldwide endeavour to develop safe and effective COVID-19 vaccines has been extraordinary, and vaccination is now underway in many countries. However, the doses available in 2021 are likely to be limited. We extended a mathematical model of SARS-CoV-2 transmission across different country settings to evaluate the public health impact of potential vaccines using WHO-developed target product profiles. We identified optimal vaccine allocation strategies within- and between-countries to maximise averted deaths under constraints on dose supply. We found that the health impact of SARS-CoV-2 vaccination depends on the cumulative population-level infection incidence when vaccination begins, the duration of natural immunity, the trajectory of the epidemic prior to vaccination, and the level of healthcare available to effectively treat those with disease. Within a country we find that for a limited supply (doses for <20% of the population) the optimal strategy is to target the elderly. However, with a larger supply, if vaccination can occur while other interventions are maintained, the optimal strategy switches to targeting key transmitters to indirectly protect the vulnerable. As supply increases, vaccines that reduce or block infection have a greater impact than those that prevent disease alone due to the indirect protection provided to high-risk groups. Given a 2 billion global dose supply in 2021, we find that a strategy in which doses are allocated to countries proportional to population size is close to optimal in averting deaths and aligns with the ethical principles agreed in pandemic preparedness planning.

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Section: Discussionmentioning

confidence: 99%

Section: Parameterisationmentioning

confidence: 99%

Within-country age-based prioritisation, global allocation, and public health impact of a vaccine against SARS-CoV-2: A mathematical modelling analysis

Hogan

Winskill

Watson

et al. 2021

Vaccine

View full text Add to dashboard Cite

show abstract

“…35 Pfizer-BioNTech vaccine effectiveness in HCWs appears preserved despite increasing B.1.1.7 incidence in the UK; however these studies have not specifically investigated cases of SGTF or sequencing-confirmed B.1.1.7. 8,36 We use an observational longitudinal cohort study of SARS-CoV-2 infection in hospital HCWs to investigate and compare the protection from SARS-CoV-2 infection conferred by vaccination and prior infection (determined using anti-spike antibody status). Additionally, we estimate the protection conferred by different vaccines, after one versus two doses and from infections with the B.1.1.7 variant confirmed by whole-genome sequencing.…”

Section: Introductionmentioning

confidence: 99%

An observational cohort study on the incidence of SARS-CoV-2 infection and B.1.1.7 variant infection in healthcare workers by antibody and vaccination status

Lumley

Rodger

Constantinides

et al. 2021

Preprint

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Background Natural and vaccine-induced immunity will play a key role in controlling the SARS-CoV-2 pandemic. SARS-CoV-2 variants have the potential to evade natural and vaccine-induced immunity. Methods In a longitudinal cohort study of healthcare workers (HCWs) in Oxfordshire, UK, we investigated the protection from symptomatic and asymptomatic PCR-confirmed SARS-CoV-2 infection conferred by vaccination (Pfizer-BioNTech BNT162b2, Oxford-AstraZeneca ChAdOx1 nCOV-19) and prior infection (determined using anti-spike antibody status), using Poisson regression adjusted for age, sex, temporal changes in incidence and role. We estimated protection conferred after one versus two vaccinations and from infections with the B.1.1.7 variant identified using whole genome sequencing. Results 13,109 HCWs participated; 8285 received the Pfizer-BioNTech vaccine (1407 two doses) and 2738 the Oxford-AstraZeneca vaccine (49 two doses). Compared to unvaccinated seronegative HCWs, natural immunity and two vaccination doses provided similar protection against symptomatic infection: no HCW vaccinated twice had symptomatic infection, and incidence was 98% lower in seropositive HCWs (adjusted incidence rate ratio 0.02 [95%CI <0.01-0.18]). Two vaccine doses or seropositivity reduced the incidence of any PCR-positive result with or without symptoms by 90% (0.10 [0.02-0.38]) and 85% (0.15 [0.08-0.26]) respectively. Single-dose vaccination reduced the incidence of symptomatic infection by 67% (0.33 [0.21-0.52]) and any PCR-positive result by 64% (0.36 [0.26-0.50]). There was no evidence of differences in immunity induced by natural infection and vaccination for infections with S-gene target failure and B.1.1.7. Conclusion Natural infection resulting in detectable anti-spike antibodies and two vaccine doses both provide robust protection against SARS-CoV-2 infection, including against the B.1.1.7 variant.

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“…A 75% reduction in asymptomatic cases of covid-19 was seen in healthcare workers at Cambridge University Hospitals NHS Foundation Trust who received one dose of the Pfizer-BioNTech vaccine in the second half of January, an analysis published as a preprint has found, adding to the evidence that the vaccine reduces transmission. A Lancet study previously found that the Oxford-AstraZeneca vaccine was 59% effective against asymptomatic transmission in some recipients 1…”

Section: Covid-19mentioning

confidence: 99%

Seven days in medicine: 24 February to 2 March 2021

2021

BMJ

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Health leader calls for review of England's ICU bed capacity Chris Hopson, chief executive of NHS Providers, which represents trust leaders, called for a review of critical care capacity in England, saying that it was "neither safe nor sensible to rely on NHS hospital trusts being able to double or triple their capacity at the drop of a hat as they've had to over the last two months." The UK has 7.3 critical care beds per 100 000 people, whereas Germany has 33.8 and the US 34.3. The review must look at the distribution of beds, proximity to patients, and a need to concentrate expertise, Hopson said.

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Single-dose BNT162b2 vaccine protects against asymptomatic SARS-CoV-2 infection

Cited by 20 publications

References 2 publications

Within-country age-based prioritisation, global allocation, and public health impact of a vaccine against SARS-CoV-2: A mathematical modelling analysis

Within-country age-based prioritisation, global allocation, and public health impact of a vaccine against SARS-CoV-2: A mathematical modelling analysis

An observational cohort study on the incidence of SARS-CoV-2 infection and B.1.1.7 variant infection in healthcare workers by antibody and vaccination status

Seven days in medicine: 24 February to 2 March 2021

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