The Emory University community is preparing to return to more normal activities as students continue to be vaccinated and the University loosens gathering restrictions. The Wheel compiled information from Emory health experts about immunity, safe activities for those who have been vaccinated and the difference between available vaccines.

Students can sign up for their vaccine on the Emory Forward page.

Adaptations made to Emory’s campus to fight COVID-19. (Caelan Bailey)

How long after getting vaccinated does it take to develop maximum immunity?

The total time after the initial dose of the vaccine to maximum protection depends on which vaccine an individual receives, but generally it takes the body about two weeks after the second dose of the Pfizer-BioNTech or Moderna vaccines or after the single-dose Johnson & Johnson (J&J) vaccine to build immunity to the virus, according to the Centers for Disease Control and Prevention (CDC).

The recommended time between two doses of the Pfizer vaccine is three weeks and the recommended time between doses of the Moderna vaccine is one month. However, an individual can still receive a second dose up to six weeks after the first if they miss their appointment or there are no appointments available, said Jodie Guest, the vice chair of the Department of Epidemiology at Rollins School of Public Health, in a virtual town hall on April 1.

“That gives you a very, very long grace period to try to get that second dose,” Guest said. “Remember that, while you’ve got great protection after your first dose, you’re not done with mRNA vaccines [Pfizer and Moderna] until you get that second one, so we would prefer you not to skip it.”

If the two doses are received within the recommended schedule, a person should develop protection from the virus five weeks after their first dose of Pfizer, six weeks after their first dose of Moderna and two weeks after their single dose of J&J.

What can you do after receiving one dose of a two-dose vaccine?

It takes two doses of the Pfizer and Moderna vaccines to achieve the full level of protection seen in clinical trials. A single dose is insufficient to prevent COVID-19 infection, according to  Executive Director of Student Health Services Sharon Rabinovitz and Associate Vice President and Executive Director of COVID-19 Response and Recovery Amir St. Clair in an April 6 email to the Wheel.

“Behaviors cannot change after the first dose of the vaccine,” the email read. “It is not uncommon for people to get infected after the first dose.”

What can you do once fully vaccinated?

The CDC has released guidelines on what activities are safe two weeks after receiving the final vaccine dose.

For example, people who are vaccinated can gather indoors with other vaccinated people without masks or physical distancing, or indoors with unvaccinated people from a single household.

Vaccinated individuals also do not have to be tested before traveling domestically or internationally, unless mandated by their destination. Individuals still have to get tested before traveling to the United States, but are not required to quarantine upon arrival, according to the CDC’s website.

Emory is still requiring that all students living on campus or using campus facilities receive regular testing, even if they have been vaccinated. 

How do the three vaccines compare in effectiveness?

The Pfizer-BioNTech vaccine was found to be “95% effective … in preventing symptomatic laboratory-confirmed COVID-19,” according to a report by the CDC. The Moderna vaccine was 94.1% effective in this respect, and the J&J vaccine was 66.3% effective.

Despite being less effective against COVID-19 overall, the J&J vaccine was 93.1% effective against COVID-19 hospitalizations 14 or more days after injection and 100% effective after 28 or more days. That is, it still provides a high level of protection against severe infections that would require hospitalization.

“The best vaccine is whichever one is available to you the fastest,” Rabinovitz and St. Clair wrote. “Data reports continue to confirm that J&J performs similarly to Pfizer and Moderna regarding effectiveness in preventing severe illness, hospitalization, and death.”

Latest cases

Emory reported 15 new cases since April 1, all of them students. This included at least five off-campus cases. There were two cases each at Clairmont Undergraduate Residential Center, Clairmont Residential Center and Raoul Hall and one case each at Woodruff Residential Center, Harris Hall and Longstreet Means Hall.