The Centers for Disease Control and Prevention (CDC) has changed rules for counting post-vaccine Covid infections and has lowered the testing threshold for PCR tests. For those who are documented as having already received a vaccine, only hospitalization or death will trigger a case record. "This shift will help maximize the quality of the data collected on cases of greatest clinical and public health importance," the website says. CDC guideline changes for the testing threshold on Covid PCR tests only apply to those who are fully vaccinated; thus, both changes will result in fewer breakthrough case reports in the U.S.
A breakthrough case is when a person is charted as having tested positive for Covid-19 after being documented as having received a full schedule of vaccinations. CDC says that breakthrough cases are expected and that they monitor them in coordination with state and local health departments. Its website states that "Experts continue to study how common these cases are" through vaccine effectiveness studies that monitor patterns in post-vaccination data, but also says they are "a small percentage." CDC data shows that as of April 26, when 95 million people had been vaccinated, the total breakthrough infections reported numbered 9,245, approximately 1/10,000—834 were hospitalizations, and 30% of the people hospitalized were asymptomatic or were not hospitalized for Covid-19. CDC warns that breakthrough cases are underreported in these numbers because of reliance on voluntary reporting from state health departments and lack of universal testing.
Health departments in the states report breakthrough cases to the CDC, who analyze the data by geographic location, type of vaccine, patient demographics—and the extent to which the bio-sampling of respiratory specimens is available for genomic sequencing—by which variant has caused the infection. A database called REDCap holds the data and allows access from "designated state health department investigators," who can then "enter, store, and manage data for cases in their jurisdiction." CDC will be monitoring and testing the State's ability to report vaccination history data in preparation for a complete transition from REDCap to the National Notifiable Diseases Surveillance System (NNDSS), while still urging that health officials report those breakthrough cases that result in hospitalization or death to the Vaccine Adverse Event Reporting System (VAERS).
CDC calls vaccines an "essential tool to protect people against COVID-19 illness" and says, "...the overall risk of hospitalization and death among fully vaccinated people will be much lower than among people with similar risk factors who are not vaccinated." Newest guidance also says that "Indoor and outdoor activities pose minimal risk to fully vaccinated people" and that "Fully vaccinated people have a reduced risk of transmitting SARS-CoV-2 to unvaccinated people." They still warn that new variants might cause illness to the vaccinated, as vaccines offer protection against "most variants," but not all.
On May 12, CDC Director Rochelle P. Walensky issued a statement of recommendation endorsing claimed "safety and effectiveness of the Pfizer-BioNTech COVID-19 vaccine and its use in 12- through 15-year-old adolescents," saying "providers may begin vaccinating them right away." The statement, from Biden appointee Walensky, came with an additional recommendation that "if your adolescent is behind on routinely recommended vaccines due to the pandemic or for other reasons, now would be a good time to work with your child’s nurse or doctor to make sure they get caught up."
May 13 updates of the CDC guidelines for "fully vaccinated people" advises they no longer need masks or social distancing unless required by local law, regulation, or workplace guidance, nor need to test or quarantine after known exposure unless they work or reside at a correctional facility or homeless shelter. Further, the fully vaccinated can travel domestically without pre- or post-testing and self-quarantining after they return. International travel no longer requires testing before departure from the U.S. unless the destination requires it, but fully vaccinated flyers who enter the U.S., including citizens, are still required to have a negative test or documentation of recovery before boarding; they do not need to self-quarantine when they arrive.
UncoverDC has extensively reported on COVID-19 And Vaccines. Larry Schweikert writes that Pollster Richard Baris found "a quarter of the American public that won’t get the vaccine under any conditions."