COVID-19 Evidence Alerts
from McMaster PLUSTM

Current best evidence for clinical care (more info)

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Primary Prevention Polack FP, Thomas SJ, Kitchin N, et al. Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine. N Engl J Med. 2020 Dec 31;383(27):2603-2615. doi: 10.1056/NEJMoa2034577. Epub 2020 Dec 10.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and the resulting coronavirus disease 2019 (Covid-19) have afflicted tens of millions of people in a worldwide pandemic. Safe and effective vaccines are needed urgently.

METHODS: In an ongoing multinational, placebo-controlled, observer-blinded, pivotal efficacy trial, we randomly assigned persons 16 years of age or older in a 1:1 ratio to receive two doses, 21 days apart, of either placebo or the BNT162b2 vaccine candidate (30 µg per dose). BNT162b2 is a lipid nanoparticle-formulated, nucleoside-modified RNA vaccine that encodes a prefusion stabilized, membrane-anchored SARS-CoV-2 full-length spike protein. The primary end points were efficacy of the vaccine against laboratory-confirmed Covid-19 and safety.

RESULTS: A total of 43,548 participants underwent randomization, of whom 43,448 received injections: 21,720 with BNT162b2 and 21,728 with placebo. There were 8 cases of Covid-19 with onset at least 7 days after the second dose among participants assigned to receive BNT162b2 and 162 cases among those assigned to placebo; BNT162b2 was 95% effective in preventing Covid-19 (95% credible interval, 90.3 to 97.6). Similar vaccine efficacy (generally 90 to 100%) was observed across subgroups defined by age, sex, race, ethnicity, baseline body-mass index, and the presence of coexisting conditions. Among 10 cases of severe Covid-19 with onset after the first dose, 9 occurred in placebo recipients and 1 in a BNT162b2 recipient. The safety profile of BNT162b2 was characterized by short-term, mild-to-moderate pain at the injection site, fatigue, and headache. The incidence of serious adverse events was low and was similar in the vaccine and placebo groups.

CONCLUSIONS: A two-dose regimen of BNT162b2 conferred 95% protection against Covid-19 in persons 16 years of age or older. Safety over a median of 2 months was similar to that of other viral vaccines. (Funded by BioNTech and Pfizer; number, NCT04368728.).

Discipline / Specialty Area Score
Family Medicine (FM)/General Practice (GP)
Emergency Medicine
General Internal Medicine-Primary Care(US)
Infectious Disease
Public Health
Hospital Doctor/Hospitalists
Internal Medicine
Occupational and Environmental Health
Pediatric Emergency Medicine
Pediatrics (General)
Comments from MORE raters

Emergency Medicine rater

This phase 2/3 trial for BNT162b2 (COVID immunization) shows high efficacity and good safety in preventing serious COVID-19 infection. However there are several important limitations: 1) the population studied did not include pregnant women, young adolescent/children, and those who are immunocompromised; 2) the follow up was only a median of 2 months (the study was planned for 2 years); 3) this study predominately studied white people and not minorities - it's not clear if the same efficacy and safety applies across different races. Regardless, this initial report is very promising.

Emergency Medicine rater

A must-read paper. We may not be giving the vaccine, but we should be prepared to see patients with adverse reactions. In addition, here is the science to back up our recommendations to patients to get the vaccine, including the importance of the second dose.

Emergency Medicine rater

This article is the RCT of the Pfizer/BioNTech COVID mRNA Vaccine. This is an excellent read in regards to the patient population included, expected adverse effects and efficacy. This study was very well done and inclusive of a large proportion of the general population. This should be required reading of all practicing clinicians.

Family Medicine (FM)/General Practice (GP) rater

As a healthcare professional, I hope this study of the COVID-19 vaccine produced by Pfizer holds true to new variants of the virus that are emerging in the UK and other countries around the world. The 95% efficacy is encouraging and provides substantial confidence in the vaccines' effectiveness at least in the short term.

General Internal Medicine-Primary Care(US) rater

We've been waiting too long for these vaccines--though these vaccines were developed in record time. I am ready for my shot.

General Internal Medicine-Primary Care(US) rater

This is the report that the entire world has been anxiously awaiting. The extremely high vaccine efficacy rate and low number of serious adverse events is remarkable. This accomplishment is also amazing based on the short work timeline. The only admonition to be noted is the lack of longer term experience with such a novel technology. Let us hope for elimination of SARS CoV-2 infections before development of any potential concerns.

Infectious Disease rater

This is obviously an extremely important paper, providing details not available in the news stories.

Infectious Disease rater

This paper has results that have been widely disseminated and I doubt that many people, even in the lay public, have not heard this. Having said that, it is especially important for the data that underlie this study to be not only public but also vetted and peer reviewed. The creation, testing and safety verification of a novel vaccine in less than a year is exceptional but even more so given the novel mechanism of action! The authors have anticipated the most common questions and have presented the data in a reassuring way. Of course, we will learn a great deal more about the efficacy, duration of protection and medium to long-term effects of this vaccine in the future. In particular, we will keep an eye out for its efficacy for mutated versions of SARS-CoV-2. We may not learn as much about long-term toxicity if placebo recipients choose to get the actual vaccine which would be ethically appropriate and even required.

Infectious Disease rater

This paper is critical for all ID and primary care providers to know. The vaccine efficacy seen here is remarkable. The study, despite the rushed production timeline, is high quality and the side effects are well documented and largely tolerable. Knowing what to expect and the efficacy are critical for advocating for this vaccine during the pandemic.

Occupational and Environmental Health rater

Although useful information, one must wonder about long-term issues as well as uncommon side effects that may occur when many more people are vaccinated. This is promising but more information is required.