Effectiveness of the BNT162b2 Covid-19 Vaccine against the B.1.1.7 and B.1.351 Variants

Abu‐Raddad, Laith J.; Chemaitelly, Hiam; Butt, Adeel A.

doi:10.1056/nejmc2104974

Cited by 912 publications

(798 citation statements)

References 4 publications

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“…In our data we do not observe increased breakthrough of either the B.1.1.7 or the B.1.351 strain 2 weeks after the second dose, yet we note our data are relatively limited in this period (76 cases, Table 1). Our results are overall aligned with recent results that have shown slightly reduced vaccine effectiveness against the B.1.1.7 and B.1.351 variants as compared to WT, 14 days after the second dose 22 .…”

Section: Discussionsupporting

confidence: 91%

Evidence for increased breakthrough rates of SARS-CoV-2 variants of concern in BNT162b2-mRNA-vaccinated individuals

Kustin

Harel

Finkel

et al. 2021

Nat Med

292

168

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The BNT162b2 mRNA vaccine is highly effective against SARS-CoV-2. However, apprehension exists that variants of concern (VOCs) may evade vaccine protection, due to evidence of reduced neutralization of the VOCs B.1.1.7 and B.1.351 by vaccine sera in laboratory assays. We performed a matched cohort study to examine the distribution of VOCs in infections of BNT162b2 mRNA vaccinees from Clalit Health Services (Israel) using viral genomic sequencing, and hypothesized that if vaccine effectiveness against a VOC is reduced, its proportion among breakthrough cases would be higher than in unvaccinated controls. Analyzing 813 viral genome sequences from nasopharyngeal swabs, we showed that vaccinees who tested positive at least 7 days after the second dose were disproportionally infected with B.1.351, compared with controls. Those who tested positive between 2 weeks after the first dose and 6 days after the second dose were disproportionally infected by B.1.1.7. These findings suggest reduced vaccine effectiveness against both VOCs within particular time windows. Our results emphasize the importance of rigorously tracking viral variants, and of increasing vaccination to prevent the spread of VOCs.

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Section: Discussionsupporting

confidence: 91%

Evidence for increased breakthrough rates of SARS-CoV-2 variants of concern in BNT162b2-mRNA-vaccinated individuals

Kustin

Harel

Finkel

et al. 2021

Nat Med

292

168

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“…In the absence of published data on transmissibility of the Delta variant we predict that this variant will have a transmission advantage relative to Wuhan-1 with D614G in individuals with pre-existing immunity from vaccines/natural infection as well as in settings where there is low vaccine coverage and low prior exposure. Lower protection against B.1.351, the variant with least sensitivity to neutralising antibodies, has been demonstrated for at least three vaccines [26][27][28][29] . However, progression to severe disease and death was low in all studies.…”

Section: Discussionmentioning

confidence: 99%

SARS-CoV-2 B.1.617.2 Delta variant emergence and vaccine breakthrough

Mlčochová¹,

Kemp²,

Dhar

et al. 2021

Preprint

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The SARS-CoV-2 B.1.617.2 (Delta) variant was first identified in the state of Maharashtra in late 2020 and has spread throughout India, displacing the B.1.1.7 (Alpha) variant and other pre-existing lineages. Mathematical modelling indicates that the growth advantage is most likely explained by a combination of increased transmissibility and immune evasion. Indeed in vitro, the delta variant is less sensitive to neutralising antibodies in sera from recovered individuals, with higher replication efficiency as compared to the Alpha variant. In an analysis of vaccine breakthrough in over 100 healthcare workers across three centres in India, the Delta variant not only dominates vaccine-breakthrough infections with higher respiratory viral loads compared to non-delta infections (Ct value of 16.5 versus 19), but also generates greater transmission between HCW as compared to B.1.1.7 or B.1.617.1 (p=0.02). In vitro, the Delta variant shows 8 fold approximately reduced sensitivity to vaccine-elicited antibodies compared to wild type Wuhan-1 bearing D614G. Serum neutralising titres against the SARS-CoV-2 Delta variant were significantly lower in participants vaccinated with ChadOx-1 as compared to BNT162b2 (GMT 3372 versus 654, p<0001). These combined epidemiological and in vitro data indicate that the dominance of the Delta variant in India has been most likely driven by a combination of evasion of neutralising antibodies in previously infected individuals and increased virus infectivity. Whilst severe disease in fully vaccinated HCW was rare, breakthrough transmission clusters in hospitals associated with the Delta variant are concerning and indicate that infection control measures need continue in the post-vaccination era.

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“…In addition, a study on the highly vaccinated population of Qatar showed that the Pfizer vaccine remained active against the UK and South African variants with respective estimated effectiveness of 89.5% and 75.0% [15]. The Moderna vaccine (mRNA-1273) vaccine can offer protection against the UK variant and is believed to be protective against the South African variant [14].…”

Section: Based On Published Analyses From Imperial College London Publicmentioning

confidence: 99%

What is Currently Known About the SARS-CoV2 Variants of Concern

Souaid¹,

Hindy²,

Kanj³

2021

JEGH

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The following four variants of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) are currently spreading worldwide and are labeled as Variants of Concern (VOC) according to the World Health Organization (WHO): the B.1.1.7 (also called 501Y. V1 or "SARS-CoV-2 VUI-202012/01") variant detected in the United Kingdom (UK) in September 2020, the B.1.351 (also called 501Y.V2) variant discovered in August 2020 in South Africa, the P.1 (also called B.1.1.28.1) variant discovered later in December 2020 in Brazil and Japan, and the B.1.617 variant discovered in India being the most recent addition to the list [1]. The three VOC from UK, South Africa and Brazil can have two mutations in common: the N501Y and E484K spike protein mutations, with the latter being more prevalent in the B.1.351 and P.1 variants [1]. According to the WHO, as of April 20, 2021, the presence of the UK, the South African and the Brazilian variants was reported respectively in 125, 67, and 43 countries, and as of May 2021, the Indian variant was recorded in 44 countries [1]. Moreover, the VOC phylodynamics are continuously updated on animated maps on the Global Initiative on Sharing All Influenza Data website. On top of these VOC, there are several additional variants of interest that are currently being investigated at national and international levels including the P.2 variant (also called B.1.1.28.2) detected in Brazil, and the CAL.20C (also called B.1.427/B.1.429) variant discovered in California [1].

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Effectiveness of the BNT162b2 Covid-19 Vaccine against the B.1.1.7 and B.1.351 Variants

Cited by 912 publications

References 4 publications

Evidence for increased breakthrough rates of SARS-CoV-2 variants of concern in BNT162b2-mRNA-vaccinated individuals

Evidence for increased breakthrough rates of SARS-CoV-2 variants of concern in BNT162b2-mRNA-vaccinated individuals

SARS-CoV-2 B.1.617.2 Delta variant emergence and vaccine breakthrough

What is Currently Known About the SARS-CoV2 Variants of Concern

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