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. 2021 Dec 15:375:e068848.
doi: 10.1136/bmj-2021-068848.

Effectiveness of mRNA-1273 against delta, mu, and other emerging variants of SARS-CoV-2: test negative case-control study

Katia J Bruxvoort  1   2 , Lina S Sy  1 , Lei Qian  1 , Bradley K Ackerson  1 , Yi Luo  1 , Gina S Lee  1 , Yun Tian  1 , Ana Florea  1 , Michael Aragones  1 , Julia E Tubert  1 , Harpreet S Takhar  1 , Jennifer H Ku  1 , Yamuna D Paila  3 , Carla A Talarico  3 , Hung Fu Tseng  1   4
Affiliations

Effectiveness of mRNA-1273 against delta, mu, and other emerging variants of SARS-CoV-2: test negative case-control study

Katia J Bruxvoort et al. BMJ. .

Abstract

Objectives: To evaluate the effectiveness of the mRNA-1273 vaccine against SARS-CoV-2 variants and assess its effectiveness against the delta variant by time since vaccination.

Design: Test negative case-control study.

Setting: Kaiser Permanente Southern California (KPSC), an integrated healthcare system.

Participants: Adult KPSC members with a SARS-CoV-2 positive test sent for whole genome sequencing or a negative test from 1 March 2021 to 27 July 2021.

Interventions: Two dose or one dose vaccination with mRNA-1273 (Moderna covid-19 vaccine) ≥14 days before specimen collection versus no covid-19 vaccination.

Main outcome measures: Outcomes included infection with SARS-CoV-2 and hospital admission with covid-19. In pre-specified analyses for each variant type, test positive cases were matched 1:5 to test negative controls on age, sex, race/ethnicity, and specimen collection date. Conditional logistic regression was used to compare odds of vaccination among cases versus controls, with adjustment for confounders. Vaccine effectiveness was calculated as (1-odds ratio)×100%.

Results: The study included 8153 cases and their matched controls. Two dose vaccine effectiveness was 86.7% (95% confidence interval 84.3% to 88.7%) against infection with the delta variant, 98.4% (96.9% to 99.1%) against alpha, 90.4% (73.9% to 96.5%) against mu, 96-98% against other identified variants, and 79.9% (76.9% to 82.5%) against unidentified variants (that is, specimens that failed sequencing). Vaccine effectiveness against hospital admission with the delta variant was 97.5% (92.7% to 99.2%). Vaccine effectiveness against infection with the delta variant declined from 94.1% (90.5% to 96.3%) 14-60 days after vaccination to 80.0% (70.2% to 86.6%) 151-180 days after vaccination. Waning was less pronounced for non-delta variants. Vaccine effectiveness against delta infection was lower among people aged ≥65 years (75.2%, 59.6% to 84.8%) than those aged 18-64 years (87.9%, 85.5% to 89.9%). One dose vaccine effectiveness was 77.0% (60.7% to 86.5%) against infection with delta.

Conclusions: Two doses of mRNA-1273 were highly effective against all SARS-CoV-2 variants, especially against hospital admission with covid-19. However, vaccine effectiveness against infection with the delta variant moderately declined with increasing time since vaccination.

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Conflict of interest statement

Competing interests: All authors have completed the ICMJE uniform disclosure form at www.icmje.org/disclosure-of-interest/ and declare: support from Moderna for the submitted work; KJB was employed by KPSC during the conduct of the study and is now an adjunct investigator at KPSC; LSS, LQ, BKA, YL, GSL, YT, AF, MA, JET, HST, JHK, and HFT are employees of KPSC, which has been contracted by Moderna to conduct this study; CAT and YDP are employees of and shareholders in Moderna Inc; KJB received funding from GlaxoSmithKline, Dynavax, Pfizer, Gilead, and Seqirus unrelated to this manuscript; LSS received funding from GlaxoSmithKline, Dynavax, and Seqirus unrelated to this manuscript; LQ received funding from GlaxoSmithKline and Dynavax unrelated to this manuscript; BKA received funding from GlaxoSmithKline, Dynavax, Seqirus, and Pfizer unrelated to this manuscript; YL received funding from GlaxoSmithKline, Seqirus, and Pfizer unrelated to this manuscript; GSL received funding from GlaxoSmithKline unrelated to this manuscript; YT received funding from GlaxoSmithKline unrelated to this manuscript; AF received funding from Pfizer, GlaxoSmithKline, and Gilead unrelated to this manuscript; MA received funding from Pfizer unrelated to this manuscript; JET received funding from Pfizer unrelated to this manuscript; HST received funding from GlaxoSmithKline, Pfizer, ALK, and Wellcome unrelated to this manuscript; JHK received funding from GlaxoSmithKline unrelated to this manuscript; HFT received funding from GlaxoSmithKline and Seqirus unrelated to this manuscript and also served on advisory boards for Janssen and Pfizer.

Figures

Fig 1
Fig 1
Vaccine effectiveness (VE) of two doses (panel A) and of one dose (panel B) of mRNA-1273 against infection with SARS-CoV-2 variants. “Other” included beta, eta, kappa, and other variants. “Unidentified” were variants for which whole genome sequencing failed
Fig 2
Fig 2
Vaccine effectiveness of two doses of mRNA-1273 against infection with SARS-CoV-2 variants by time since vaccination. Non-delta variants included alpha, epsilon, gamma, iota, mu, and other (beta, eta, kappa, and other variants). Unidentified variants were those for which whole genome sequencing failed
See this image and copyright information in PMC

Comment in

References

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