New Studies Suggest People Who Have Recovered From COVID-19 Should Still Get One Vaccine Dose


Safeway pharmacist Ashley McGee fills a syringe with the Pfizer COVID-19 vaccination in California on Oct. 1, 2021. (Justin Sullivan/Getty Images)


By Katabella Roberts

New research from the University of California San Francisco (UCSF) and University of Minnesota (UMN) suggest that individuals who have recovered from COVID-19 should still receive one vaccination shot.

The research from UCSF was published on Sept. 25. Scientists evaluated the humoral and cell-mediated response elicited by the Pfizer-BioNTech vaccine in individuals who had contracted COVID-19 and those who had not.

The study focused on 145 health care workers between the ages of 21 and 69 who received a vaccination between Dec. 27, 2020 and Feb. 11, 2021, of which 127 had not had COVID-19 prior to vaccination and 18 had.

Analyses were performed before vaccination, after the second vaccine administration, and 21 days after the second dose.

The results showed that all 18 of the individuals who had contracted COVID-19 experienced higher antibody levels after the second vaccination, while those who had not previously had the virus also experienced increased antibody levels but at significantly lower levels than experienced subjects did.

Meanwhile, levels of antibodies in subjects who had not had COVID-19 prior to vaccination were significantly lower than baseline levels of those who had.

At 21 days after having the second dose of vaccine, the individuals who previously had COVID-19 still experienced higher antibody levels than those who had not.

“In this study, we reported that almost all vaccinated healthy subjects developed a sustained cellular and humoral response after complete vaccination. Moreover, the response level is higher in those subjects with previous exposure to SARS-CoV-2,” the researchers concluded.

“SARS-CoV-2-naïve individuals developed a humoral response higher than that observed after natural infection after two vaccine doses but not after one vaccine dose, when about 6% of individuals were still negative for SARS-CoV-2 NT antibodies.”

“On the other side, the cell-mediated response was detectable in 98.4% naïve individuals after two doses of vaccine, whereas one vaccine dose was not sufficient for eliciting detectable SARS-CoV-2 T-cell response in 32.1% of subjects,” they wrote.

“Conversely, both humoral and cellular responses were strongly induced after the first dose of the BNT162b2 vaccine in SARS-CoV-2-experienced subjects: therefore, it appears that prime vaccine dose acts as a boost in these subjects.”

A separate study (pdf) conducted by the University of Minnesota (UMN), that was published a day earlier as a pre-print, compared blood samples following COVID-19 vaccinations in 48 participants.

Epoch Times Photo
Medical staff and community members protested vaccine mandates in front of Rady Children’s Hospital. Registered nurse Alicia Fregoso wrote on a sign that she acquired natural immunity to COVID-19 in San Diego, on Oct. 1, 2021. (Jane Yang/The Epoch Times)

That research also found that people who were previously infected with the CCP (Chinese Communist Party) virus gained five times more memory B cells—which are capable of producing antibodies that fight off the virus—than those who weren’t.

“Although both groups end up with affinity-matured MBCs (memory B cells), many capable of recognizing a variant of concern, CoV2-infected people have 5 times more MBCs than CoV2-naive subjects,” the authors of the study concluded.

“The significance of this difference in terms of immunity to subsequent CoV2 infection should remain an area of active investigation, especially since the antibodies in CoV2-infected individuals who are then vaccinated are very good at neutralizing the both the original and variant CoV2 viruses.”

The latest UCSF and UMN studies throw weight behind the argument among some scientists that individuals who have developed “natural immunity” after infection with COVID-19 should still have at least one vaccination shot.

Dr. David Boulware, professor of medicine at the University of Minnesota, told The Epoch Times that he recommends people with prior infection receive at least one dose of vaccine to generate these memory B and antigen-specific T cells at more than three to six months after the initial infection.

Boulware noted that the “longer the interval, the better,” and that getting a single dose of the vaccine after more than six months would be his personal preference.

Last month, U.S. District Court Judge James Selna in Santa Ana, California, upheld the University of California’s COVID-19 vaccine requirement after it was challenged by a professor who claimed to have immunity due to a prior CCP virus infection.

Just last week, a group of Republican members of Congress who are also physicians wrote to the Centers for Disease Control and Prevention urging it to acknowledge natural immunity. The group stated that failure to do so may result in labor shortages as people lose their jobs for failing to get vaccinated.

Reuters contributed to this report.