Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Jul;2(7):e279-e280.
doi: 10.1016/S2666-5247(21)00069-0. Epub 2021 Apr 20.

COVID-19 vaccine efficacy and effectiveness-the elephant (not) in the room

Piero Olliaro  1 , Els Torreele  2 , Michel Vaillant  3
Affiliations

COVID-19 vaccine efficacy and effectiveness-the elephant (not) in the room

Piero Olliaro et al. Lancet Microbe. 2021 Jul.

Erratum in

No abstract available

PubMed Disclaimer

Conflict of interest statement

We declare no competing interests.

Figures

Figure
Figure
RRR and NNV with 95% CI ranked by attack rate in the unvaccinated (placebo) group for five COVID-19 vaccines The lower the NNV and the higher the RRR, the better the vaccine efficacy. Details are in the appendix (p 3). RRR=relative risk reduction. NNV=numbers needed to vaccinate. NIH=US National Institutes of Health.
See this image and copyright information in PMC

Comment in

References

    1. Zimmer C, Corum J, Wee S-L. Covid-19 Vaccine Tracker. https://www.nytimes.com/interactive/2020/science/coronavirus-vaccine-tra...
    1. Polack FP, Thomas SJ, Kitchin N, et al. Safety and efficacy of the BNT162b2 mRNA COVID-19 Vaccine. N Engl J Med. 2020;383:2603–2615. - PMC - PubMed
    1. Baden LR, El Sahly HM, Essink B, et al. Efficacy and safety of the mRNA-1273 SARS-CoV-2 Vaccine. N Engl J Med. 2021;384:403–416. - PMC - PubMed
    1. Voysey M, Clemens SAC, Madhi SA, et al. Safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) against SARS-CoV-2: an interim analysis of four randomised controlled trials in Brazil, South Africa, and the UK. Lancet. 2021;397:99–111. - PMC - PubMed
    1. Logunov DY, Dolzhikova IV, Shcheblyakov DV, et al. Safety and efficacy of an rAd26 and rAd5 vector-based heterologous prime-boost COVID-19 vaccine: an interim analysis of a randomised controlled phase 3 trial in Russia. Lancet. 2021;397:671–681. - PMC - PubMed

Substances