High Levels of Antibodies Found in People Previously Infected with COVID-19 After Single Dose of mRNA Vaccine

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A new study from NYU Grossman School of Medicine found that people previously infected with SARS-CoV-2 may produce levels of antibodies against coronavirus disease (COVID-19) after one dose of the Pfizer-BioNTech messenger RNA (mRNA) vaccine that are equal to or higher than people not previously infected have after two doses. The study, led by Mark J. Mulligan, MD, director of the Division of Infectious Diseases and Immunology and director of the Vaccine Center, suggests that the immune responses in most patients previously infected with the pandemic virus did not improve further after a second dose of vaccine. The findings support a hypothesis that SARS-CoV-2-experienced people may require only a single dose of mRNA vaccine.

Key Takeaways:

  • The study found that people previously infected with SARS-CoV-2 may produce high levels of antibodies against COVID-19 after one dose of the Pfizer-BioNTech mRNA vaccine, equal to or higher than people not previously infected have after two doses.
  • The immune responses in most patients previously infected with the pandemic virus did not improve further after a second dose of vaccine.
  • The authors suggest that SARS-CoV-2-experienced people may require only a single dose of mRNA vaccine.
  • The study was led by researchers from NYU Grossman School of Medicine, under the auspices of NYU Langone's Vaccine Center.
  • The Pfizer vaccine had received an Emergency Use Authorization from the U.S. Food and Drug Administration (FDA) on December 12, 2020.
  • Between December 14, 2020, and March 7, 2021, more than 90 million doses of the study vaccine were administered, but just 17.7 percent of the U.S. population had received one or more doses of a vaccine.

Statistics:

  • Over 90 million doses of the study vaccine were administered between December 14, 2020, and March 7, 2021.
  • Just 17.7 percent of the U.S. population had received one or more doses of a vaccine between December 14, 2020, and March 7, 2021.
  • The study used 33 participants, with 14 having a history of COVID-19 (median age 41, 71 percent female, range of severity), while 19 had not been exposed to SARS-CoV-2.
  • The study used enzyme-linked immunosorbent assay (ELISA) to compare immune responses after one and two doses of vaccine.

Sources:

  • NYU Langone Health (March 9)
  • U.S. Food and Drug Administration (December 12, 2020)
  • Centers for Disease Control and Prevention (March 7, 2021)
  • National Institutes of Health (study funding source)