Current shortages in COVID-19 vaccine production and distribution have led some experts to suggest untested regimens. Persons who have had COVID-19 are thought to have protective immunity and memory responses for at least 6 months; however, neither recall responses nor ideal vaccine dosing regimens have been studied in those previously infected with SARS-CoV-2. A recent study on whether health care workers with previous COVID-19 infection could mount recall responses to a single dose of an mRNA-based COVID-19 vaccine was published in JAMA Network.

Health care workers with previous COVID-19 infection, based on laboratory-confirmed serology testing, had higher antibody titer responses to a single dose of mRNA vaccine than those who were not previously infected. Antibody titers started peaking at 7 days and achieved higher titers and neutralization in 14 days compared with Ab-negative volunteers.

This likely explains why many people respond with more adverse reactions to the second dose of the mRNA vaccine! That is good news although if you were one of the unlucky ones who reacted you might disagree! Stay the course, stay well, mask up, get vaccinated and stay tuned!