Monday, March 29, 2021

Vaccine update: Frequently asked questions

Do you gain some immunity to the virus after the first vaccination, or only after the second? What about for the Johnson & Johnson vaccine?

It typically takes two weeks after vaccination for the body to build protection (immunity) against the virus that causes COVID-19. That means it is possible a person could still get COVID-19 before or just after vaccination because the vaccine did not have enough time to provide protection. People are considered most protected two weeks after their second dose of the Pfizer-BioNTech or Moderna COVID-19 vaccine, or two weeks after the single-dose Johnson & Johnson’s Janssen COVID-19 vaccine.

Source: CDC

I saw that there are new strains of the virus emerging in the United Kingdom. Will the Pfizer-BioNTech and Moderna vaccines protect against these strains?

At this time, it appears that the vaccines protect against the new strain identified in the United Kingdom. However, to be doubly safe, it continues to be very important that we all continue to practice the safety precautions of mask wearing, social distancing, hand washing, and avoiding gatherings.

For campus vaccination information and updates, see the vaccine information page on the UI Coronavirus website. To learn more about vaccines and vaccine safety, see the University of Iowa Health Care COVID-19 vaccine information page.

More information about the state of Iowa’s vaccine administration is available on the state’s COVID-19 vaccine administration dashboard.

Campus operations

The university continues to monitor self-reported COVID-19 testing data on campus, while also tracking state, region, and national COVID-19 infection rates.

University of Iowa seven-day rolling average

University of Iowa self-reported COVID-19 testing

These data reflect new cases since March 26, 2021.

The University of Iowa has published an updated snapshot of self-reported positive COVID-19 tests from faculty, staff, and students.

Number of self-reported cases of COVID-19


  • New cases: 11
  • Total cases: 3,080


  • New cases: 2
  • Total cases: 462

These numbers reflect only self-reported positive or presumed positive COVID-19 tests from UI faculty, staff, and students on the academic campus since Aug. 18, 2020. These data will not match data reported by UI Hospitals & Clinics or by the Iowa Department of Public Health for several reasons, including different testing time intervals and geographic scope. Students who also are employees of the university are only reported in the student number to avoid double counting. The UI has more than 30,000 students and nearly 30,000 employees. Many employees continue to work remotely but have self-reported to authorize sick leave.

Number of residence hall students in quarantine: 0*

Number of residence hall students in self-isolation: 3**

*Quarantine: Quarantine is used to keep someone who might have been exposed to COVID-19 away from others.

**Self-isolation: Isolation is used to separate people infected.