This is based on VAERS data. I encourage the curious to look at this data. I did. I would characterize its quality as so poor that probably no conclusions at all can be drawn from it. And I usually find myself defending the use of noisy and/or small data in similar situations.
https://www.cdc.gov/vaccinesafety/ensuringsafety/monitoring/...
> The Vaccine Safety Datalink (VSD) is a collaborative project between CDC’s Immunization Safety Office and nine health care organizations. The VSD started in 1990 and continues today in order to monitor safety of vaccines and conduct studies about rare and serious adverse events following immunization.
The nine HMOs are:
Kaiser Permanente Washington, Seattle, WA
Harvard Pilgrim Health Care Institute, Boston, MA
HealthPartners Institute, Minneapolis, MN
Kaiser Permanente Northwest, Portland, OR
Kaiser Permanente Northern CA
Kaiser Permanente CO
Denver Health, CO
Marshfield Clinic Research Institute, WI
Kaiser Permanente Southern CA