Single Shot of COVID-19 Vaccine Boosts Antibodies in Recovered Patients

The COVID-19 pandemic, caused by the coronavirus SARS-CoV-2, continues to disrupt life in many countries. Large amounts of effective vaccines are urgently needed to fight the pandemic. In addition, it is not entirely clear how long recovered COVID-19 patients might be immune against reinfection and how well a previous infection with the wild-type protects against newer virus variants such as B.1.351 (first identified in South Africa). Immunizing recovered patients could, thus, still be important.

Leonidas Stamatatos, Juliana McElrath, Andrew T. McGuire, Fred Hutchinson Cancer Research Center, and University of Washington, both Seattle, WA, USA, and colleagues have investigated how well previous infections protect against the B.1.351 variant and what antibody responses they induce to B.1.351 pseudoviruses and to SARS-CoV-1 pseudoviruses. Then they checked the responses after vaccinations with the Pfizer/BioNTech or Moderna mRNA vaccines. The team also compared the antibody responses to those in previously uninfected individuals who received the same vaccines.

The researchers found that blood serum from the recovered patients—before vaccination—neutralized the original virus and, in a few cases, neutralized B.1.351. A single vaccine dose significantly boosted the levels of neutralizing antibodies against the studied SARS-CoV-2 variants, and even provided low levels of serum neutralizing activity against SARS-CoV-1. The previously infected individuals also produced higher levels of antibodies after one dose than uninfected people who had received two vaccine doses. A second dose of the vaccine had no further effect on those who were previously infected. According to the team, this work shows the importance of vaccinating both uninfected persons and those that have recovered from COVID-19.

mRNA vaccination boosts cross-variant neutralizing antibodies elicited by SARS-CoV-2 infection,
Leonidas Stamatatos, Julie Czartoski, Yu-Hsin Wan, Leah J. Homad, Vanessa Rubin, Hayley Glantz, Moni Neradilek, Emilie Seydoux, Madeleine F. Jennewein, Anna J. MacCamy, Junli Feng, Gregory Mize, Stephen C. De Rosa, Andrés Finzi, Maria P. Lemos, Kristen W. Cohen, Zoe Moodie, M. Juliana McElrath, Andrew T. McGuire,
Science 2021.
https://doi.org/10.1126/science.abg9175

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