HealthDay News — Individuals previously infected with SARS-CoV-2 infection have antibody responses to 1 dose of the Pfizer-BioNTech mRNA vaccine that are comparable to antibody responses of infection-naive individuals receiving 2 doses, according to a study published in Nature Medicine.
Joseph E. Ebinger, MD, from the Cedars-Sinai Medical Center in Los Angeles, and colleagues enrolled 1090 health care workers from an academic medical center in Southern California who received the Pfizer-BioNTech mRNA vaccine. Antibody levels were measured at 3 time points: before or up to 3 days after dose 1, within 7 to 21 days after dose 1, and within 7 to 21 days after dose 2.
The researcher found that for individuals with prior SARS-CoV-2 infection (35 individuals), spike-specific immunoglobulin G antibody levels and angiotensin-converting enzyme 2 antibody binding inhibition responses elicited by a single vaccine dose were similar to those seen after 2 doses of vaccine in 228 individuals without prior infection. Postvaccine symptoms were experienced more often by individuals with previous SARS-CoV-2 infection than infection-naive individuals after dose 1 (36.8% vs 25.0%), but there was no difference between the groups in postvaccine symptoms after dose 2 (51.3% vs 58.7%).
“It appears that a single booster dose given to previously infected individuals offers the same benefit as 2 doses given to people without prior infection,” a coauthor said in a statement.