Previously Infected May Only Need Single Dose of COVID-19 Vaccine
Spike-specific IgG antibody levels and ACE2 antibody binding inhibition responses similar to those in infection-naive after two doses
MONDAY, April 5, 2021 (HealthDay News) -- Individuals previously infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection have antibody responses to one dose of the BNT162b2 (Pfizer-BioNTech) mRNA vaccine that are comparable to those of infection-naive individuals receiving two doses, according to a study published online April 1 in Nature Medicine.
Joseph E. Ebinger, M.D., from the Cedars-Sinai Medical Center in Los Angeles, and colleagues enrolled 1,090 health care workers from an academic medical center in Southern California who received BNT162b2 mRNA vaccine. Antibody levels were measured at three time points: before or up to three days after dose one, within seven to 21 days after dose one, and within seven to 21 days after dose two.
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 two 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 one (36.8 versus 25.0 percent), but there was no difference between the groups in postvaccine symptoms after dose two (51.3 versus 58.7 percent).
"It appears that a single booster dose given to previously infected individuals offers the same benefit as two doses given to people without prior infection," a coauthor said in a statement.