Intended for healthcare professionals


Covid-19: Vaccine candidate may be more than 90% effective, interim results indicate

BMJ 2020; 371 doi: (Published 09 November 2020) Cite this as: BMJ 2020;371:m4347

Read our latest coverage of the coronavirus outbreak

  1. Elisabeth Mahase
  1. The BMJ

A vaccine candidate developed by Pfizer and BioNTech may be more than 90% effective in preventing covid-19 in participants without prior infection, the first interim analysis of the phase III trial shows.

The research team evaluated the results after 94 cases of covid-19 had been confirmed. The study began in July and has so far enrolled nearly 44 000 participants, just under 39 000 of whom have received a second dose of the mRNA vaccine candidate (as of 8 November).

The team’s announcement said, “The case split between vaccinated individuals and those who received the placebo indicates a vaccine efficacy rate above 90%, at seven days after the second dose. This means that protection is achieved 28 days after the initiation of the vaccination, which consists of a two-dose schedule.” However, the results, which are the first from any phase III trial of a covid-19 vaccine, have been shared only by press release and have not yet been published or …

View Full Text