Melissa Morelli, a teacher who works with special-needs children, woke up on July 19 with a stuffy nose, a headache and a bit of a cough. “I didn't think anything of it, because mild colds always make the rounds [in school],” says Morelli, who had the Pfizer vaccine in January and February. “I took some Tylenol and went about my week. ... COVID never crossed my mind."
It wasn't until six days later, when she landed in the ER for an unrelated problem — she had skimped on water despite the hot weather, got dehydrated and fainted — that she learned she had COVID-19. “In hindsight, I wish I had thought about it more and went to get tested after I had some cold symptoms,” she says.
As the contagious delta variant continues to circulate, more vaccinated Americans are developing so-called breakthrough infections — defined as those that occur two weeks or more after completion of their vaccine regimen, be it a one- or two-dose version. No one knows exactly how often this is happening, because many breakthrough cases are completely asymptomatic and because the Centers for Disease Control and Prevention (CDC) has stopped tracking them unless they lead to hospitalization or death.
Based on the currently available evidence, such breakthroughs are believed to be fairly rare and mostly mild, says Perry N. Halkitis, dean of the Rutgers School of Public Health. The overwhelming majority of those who develop symptoms end up with minor coldlike ones similar to what Morelli experienced, though of course there are exceptions.
Jennifer Leascher had her second Moderna shot in February, and in early July, she tested positive for COVID. Unlike Morelli, however, Leascher's condition quickly worsened, and she was hospitalized with COVID pneumonia for four days. No one can explain to her why she got so sick.
"I'm 58 and have been an avid runner since 1997,” says Leascher, who is now recovering at home. “I do have hypothyroidism and asthma, but both were well managed."