Research status of coronavirus disease 2019 mRNA vaccine-associated lymphadenopathy.

ABSTRACT

After administration of coronavirus disease 2019 (COVID-19) mRNA vaccine (BNT162b2 vaccine of Pfizer/BioNTech incorporation and mRNA-1273 vaccine of Moderna incorporation), some vacci- nators develop vaccination-associated lymphadenopathy (VAL). VAL usually occurs 2 to 4 days after vacci- nation, or 2 weeks later. The incidence of VAL after the second dose of vaccine is higher than that after the first dose. Some vaccinators develop VAL after both the first and second doses of vaccination. The clinical manifestations of VAL are enlarged lymph nodes with pain in axilla, supraclavicular, neck, and inguen on the same side of the inoculation site. Imaging examination shows enlarged lymph nodes with diffuse or focal cortical thickening, etc. The pathological diagnosis is benign reactive lymphadenopathy. VAL does not need treatment and generally subsides spontaneously 5 to 16 days after onset. The mechanism of lymphadenopathy after administration of COVID-19 mRNA vaccine is unclear.Copyright © 2021 Science Press (China).