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Don't VAERS reports show vaccines are dangerous?

Here is what the checked sources say. Each title links to the original.

  1. Safety monitoring in the Vaccine Adverse Event Reporting System (VAERS)

    Vaccine, 2015, study

    A review by CDC and FDA scientists explaining how VAERS works. VAERS is a passive system: anyone can report any health problem after a vaccine, whether or not the vaccine caused it. The authors say it is mainly for spotting possible warning signs to study further. It has no unvaccinated comparison group, so it cannot show whether vaccinated people have more of a problem. Events are underreported, especially mild ones, while media attention can cause extra reports. Read alone, the authors warn, report counts can mislead about cause and about how often problems happen.

  2. Vaccine Safety: Are Vaccines Safe?

    Children's Hospital of Philadelphia Vaccine Education Center, 2020, explainer

    CHOP acknowledges vaccines are not risk-free and gives one historical example of surveillance catching a real problem. After the first rotavirus vaccine (RotaShield) was given to about 1 million children, VAERS picked up about 15 reports of intestinal blockage (intussusception). CDC suspended its use, and its analysis found intussusception in about 10 of every 100,000 vaccinated children. CHOP says systems like the Vaccine Safety Datalink, which also measure rates in unvaccinated children, are better than VAERS for estimating risk and investigating whether a vaccine caused an event.

  3. Reports of Anaphylaxis After Receipt of mRNA COVID-19 Vaccines in the US-December 14, 2020-January 18, 2021

    JAMA, 2021, study

    CDC doctors reviewed VAERS reports of suspected anaphylaxis, a potentially life-threatening allergic reaction, after the first 17.5 million US mRNA COVID-19 doses (December 14, 2020 to January 18, 2021). 66 reports met a standard clinical case definition, giving early reporting rates from this passive system of 4.7 per million Pfizer doses and 2.5 per million Moderna doses. Most reactions began within minutes; 32 people were hospitalized, 7 needed a breathing tube, all were treated, and no deaths were reported among these cases. Anaphylaxis is a real but rare risk.

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