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A Project of The Annenberg Public Policy Center
SciCheck’s COVID-19/Vaccination Project

Video Twists Advice on Delta Variant and Vaccination

Video Twists Advice on Delta Variant and Vaccination

An epidemiologist recommended that people get the COVID-19 vaccine because some evidence suggests an unvaccinated person who gets the delta variant is “twice as likely to require hospital treatment” than someone infected with the alpha variant. But a Facebook video twists that advice to claim that he said vaccinated people would be twice as likely to be hospitalized.

Irish Professor Makes Unfounded Claims About Long-Term Effects of mRNA Vaccines

Irish Professor Makes Unfounded Claims About Long-Term Effects of mRNA Vaccines

The COVID-19 mRNA vaccines authorized for use were found to be safe and effective in clinical trials and real-world conditions. A professor in Ireland baselessly claims in a video circulating on social media that they are not, and that those who get the vaccines will die as a result within several years.

Texas Doctor Spreads False Claims About COVID-19 Vaccines

Texas Doctor Spreads False Claims About COVID-19 Vaccines

Federal officials authorized two mRNA vaccines for COVID-19 after they were determined to be safe and effective against symptomatic illness in clinical trials. But a Texas doctor, in a widely shared video, falsely claims the vaccines don’t provide protection and that they’re actually “experimental gene therapy.”

What does it mean to say a vaccine has 94% percent efficacy or higher?

Efficacy is a measure of how well a vaccine performs in a clinical trial. It specifically refers to a relative reduction in infection or disease when comparing the vaccinated group to the placebo (or control) group.
For instance, both the Pfizer/BioNTech and Moderna vaccines were primarily evaluated for their ability to prevent symptomatic COVID-19, with the former having a 95% efficacy and the latter having a 94% efficacy in the clinical trial data submitted for the original authorization by the Food and Drug Administration.

How effective are the vaccines?

All of the authorized and approved vaccines are effective at preventing severe COVID-19.
Against earlier forms of the coronavirus, the vaccines were highly effective at preventing symptomatic illness. For example, clinical trials for the Pfizer/BioNTech and Moderna mRNA vaccines and the protein-based Novavax vaccine found each reduced the risk of getting sick by more than 90%.
Subsequent studies have demonstrated that the vaccines are effective under real-world conditions. Against omicron variants,

How long will a person be protected if vaccinated?

It’s not known exactly how long vaccination lasts, particularly against the omicron variant. But studies of previous variants have suggested that COVID-19 vaccination protects against infection or mild disease for several months, while protection against more serious illness is longer-lasting, on the order of six months or more.
A systematic review of studies conducted prior to omicron, for example, found that for the four main COVID-19 vaccines used worldwide,

A Guide to Moderna’s COVID-19 Vaccine

A Guide to Moderna’s COVID-19 Vaccine

Moderna’s mRNA vaccine is the second COVID-19 vaccine to be authorized and fully approved for use in the U.S. Here, we give a rundown of basic facts about the vaccine and an overview of how it works.

Q&A on COVID-19 Vaccines

Q&A on COVID-19 Vaccines

Three COVID-19 vaccines are now authorized in the U.S. In this story, we answer some common questions about the shots.