SARS-CoV-2 vaccine breakthrough infections with the alpha variant are asymptomatic or mildly symptomatic among health care workers

Rovida, Francesca; Cassaniti, Irene; Paolucci, Stefania; Percivalle, Elena; Sarasini, Antonella; Piralla, Antonio; Giardina, Federica; Sammartino, José Camilla; Ferrari, Alessandro; Bergami, Federica; Muzzi, A; Novelli, Viola; Meloni, A; Cutti, Sara; Grugnetti, Anna Maria; Grugnetti, Giuseppina; Rona, Claudia; Daglio, Marinella; Marena, Carlo; Triarico, Antonio; Lilleri, Daniele; Baldanti, Fausto

doi:10.1101/2021.06.29.21259500

Cited by 15 publications

(23 citation statements)

References 23 publications

(16 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Encouragingly, however, breakthrough infections appear to infrequently result in onwards transmission, and to occur less often in previously exposed individuals who have been vaccinated. 155 Overall, data on the immune response to VOCs demonstrate the need for broadly protective SARS-CoV-2 vaccines (as also suggested by several others 6,163 ). Although the mutation rate of coronaviruses is notably lower than, for example, that for influenza A virus-and hence, in the majority of vaccinated individuals, protection is unlikely to be lost completely beyond 12 months 170 -in the shortto-medium term current vaccines will require updating to maintain their effectiveness; indeed, this development is already underway for the gamma and beta variants.…”

Section: Immune Response Against Variants Of Concernmentioning

confidence: 52%

“…Such an approach is supported by data showing that breakthrough infections among recipients of a second dose occur less often in previously exposed than in unexposed individuals (3-month cumulative incidence of 0•42% among previously exposed BNT162b2 booster-dose recipients compared with 0•90% among unexposed booster-dose recipients). 155 Despite this, in resource-poor settings with limited vaccine stocks, focusing second doses on those previously unexposed 153 could provide a means of resource allocation that lessens the burden on public health systems.…”

Section: Conventional Prime-boost Strategymentioning

confidence: 99%

“…167 Other reports of similar breakthrough infections with VOCs are also emerging. 155,168 Of the study designs that allow for prevalence estimation, breakthrough infections have thus far been identified among prime-dose recipients with a prevalence of 2•6% (BNT162b2 or mRNA-1273 vaccinees, no sequencing performed), 169 and among booster-dose recipients with a prevalence of 0•48% (BNT162b2 or mRNA-1273 vaccinees, alpha variant or iota-like variant [B.1.526 lineage]), 166 0•89% (BNT162b2 vaccinees, all alpha variant), 155 and 2•0% (BNT162b2 or mRNA-1273 vaccinees, no sequencing performed). 169 Another study, which did not group participants by vaccine dose, found a prevalence of breakthrough infections of 1•13% among individuals who received the BNT162b2 or mRNA-1273 vaccines, although no sequencing was performed to identify the variants.…”

Section: Immune Response Against Variants Of Concernmentioning

confidence: 99%

See 2 more Smart Citations

Does infection with or vaccination against SARS-CoV-2 lead to lasting immunity?

Milne

Hames

Scotton

et al. 2021

The Lancet Respiratory Medicine

123

View full text Add to dashboard Cite

Many nations are pursuing the rollout of SARS-CoV-2 vaccines as an exit strategy from unprecedented COVID-19related restrictions. However, the success of this strategy relies critically on the duration of protective immunity resulting from both natural infection and vaccination. SARS-CoV-2 infection elicits an adaptive immune response against a large breadth of viral epitopes, although the duration of the response varies with age and disease severity. Current evidence from case studies and large observational studies suggests that, consistent with research on other common respiratory viruses, a protective immunological response lasts for approximately 5-12 months from primary infection, with reinfection being more likely given an insufficiently robust primary humoral response. Markers of humoral and cell-mediated immune memory can persist over many months, and might help to mitigate against severe disease upon reinfection. Emerging data, including evidence of breakthrough infections, suggest that vaccine effectiveness might be reduced significantly against emerging variants of concern, and hence secondary vaccines will need to be developed to maintain population-level protective immunity. Nonetheless, other interventions will also be required, with further outbreaks likely to occur due to antigenic drift, selective pressures for novel variants, and global population mobility.

show abstract

Section: Immune Response Against Variants Of Concernmentioning

confidence: 52%

Section: Conventional Prime-boost Strategymentioning

confidence: 99%

Section: Immune Response Against Variants Of Concernmentioning

confidence: 99%

See 1 more Smart Citation

Does infection with or vaccination against SARS-CoV-2 lead to lasting immunity?

Milne

Hames

Scotton

et al. 2021

The Lancet Respiratory Medicine

123

View full text Add to dashboard Cite

show abstract

“…In addition, vaccinated individuals may generally be less likely to be tested due to asymptomatic or mild symptomatic infection (cf. [28]), which may induce larger dark figures of infections in the vaccinated part of the population. Such vaccination effects are expected to further complicate the reliable estimation Estimating the course of the COVID-19 pandemic in Germany of the effective reproduction number based only on the numbers of confirmed cases.…”

Section: Discussionmentioning

confidence: 99%

Estimating the Course of the COVID-19 Pandemic in Germany via Spline-based Hierarchical Modelling of Death Counts

Wistuba

Mayr

Staerk

2021

Preprint

View full text Add to dashboard Cite

The effective reproduction number is a key figure in context of the COVID-19 pandemic, which is typically estimated based on daily confirmed cases. Here, we consider a retrospective modelling approach for estimating effective reproduction numbers based on death counts during the first year of the pandemic in Germany. The proposed Bayesian hierarchical model incorporates splines to estimate reproduction numbers flexibly over time while adjusting for varying effective infection fatality rates. The approach also provides estimates of dark figures regarding undetected infections over time. Results for Germany illustrate that estimates based on death counts are often similar to classical estimates based on confirmed cases. However, considering death counts is more robust against shifts in testing policies: in particular, confirmed cases indicate a spike in the effective reproduction number linked to a local super-spreading event in June 2020, whereas our model does not estimate a spike but reduced dark figures of infections. During the second wave of infections, classical estimates suggest a flattening trend of infections following the "lockdown light" in November 2020, while our results indicate that infections continued to rise until the "second lockdown" in December 2020. This observation is associated with more stringent testing criteria introduced concurrently with the "lockdown light", which is reflected in subsequently increasing dark figures of infections estimated by our model. In light of progressive vaccinations, shifting the focus from modelling confirmed cases to reported deaths with the possibility to incorporate effective infection fatality rates might be of increasing relevance for the future surveillance of the pandemic.

show abstract

“…Other studies included were Tartof et al 2021, 11 Skowronski et al 2021, 12 Lin et al 2021, 13 Chemaitelly et al 14 Andrews et al, 2021, 16 Self et al 2021. 17 Points reflected midpoints for each VE time interval reported (e.g., if VE was reported for days 14-28 following last vaccine dose, VE for that period was plotted at day 21).…”

Section: Supplementary Materialsmentioning

confidence: 99%

Durability of protection post-primary COVID-19 vaccination in the US: matched case-control study

Zheutlin

Ott

Sun

et al. 2022

Preprint

View full text Add to dashboard Cite

Objectives: Determine durability of protection by the three currently available COVID-19 vaccines in the United States (US) following primary vaccination against breakthrough infections, hospitalizations, and intensive care unit (ICU) admissions. Methods: Using claims and laboratory data covering 168 million lives, we conducted a matched case-control study with fully vaccinated individuals between January 1 and September 7, 2021. Odds ratios (OR) for developing outcomes in months two through six following full vaccination were estimated relative to the first month after full vaccination for each vaccine separately. Results: Evidence of waning protection against infections started in month 2 from vaccination for both BNT162b2 (OR [95% CI] in month 6+, 2.93 [2.72, 3.15]) and mRNA-1273 (OR [95% CI] in month 6+, 2.76 [2.51, 3.04]), and in month 4 for Ad26.COV2.S (OR [95% CI] in month 5+, 1.31 [1.18, 1.47]). Evidence of waning protection against hospitalization started in month 2 for BNT162b2 (OR [95% CI], 3.97 [3.26, 4.83] in month 6+) and in month 3 for mRNA-1273 (OR 95% CI, 1.66 [1.26, 2.19] in month 6+). There was no evidence of waning protection against hospitalization for Ad26.COV2.S (OR [95% CI], 1.25 [0.86, 1.80] in month 5+). No waning of protection was observed at any time for ICU admissions for all three vaccines. Conclusions: Following primary vaccination, all three vaccines showed strong and durable protection against ICU admissions. Ad26.COV2.S showed a more durable level of protection against breakthrough infections and hospitalizations in line with published evidence of its durable antibody and cellular immune response, although its Vaccine Effectiveness (VE) at baseline after a single-dose is lower than that for the two-dose mRNA vaccines. Additional studies are needed to understand durability following homologous or heterologous boosters.

show abstract

SARS-CoV-2 vaccine breakthrough infections with the alpha variant are asymptomatic or mildly symptomatic among health care workers

Cited by 15 publications

References 23 publications

Does infection with or vaccination against SARS-CoV-2 lead to lasting immunity?

Does infection with or vaccination against SARS-CoV-2 lead to lasting immunity?

Estimating the Course of the COVID-19 Pandemic in Germany via Spline-based Hierarchical Modelling of Death Counts

Durability of protection post-primary COVID-19 vaccination in the US: matched case-control study

Contact Info

Product

Resources

About