Influence of past infection with SARS-CoV-2 on the response to the BNT162b2 mRNA vaccine in health care workers: Kinetics and durability of the humoral immune response
Jesús Ontañón,
Joaquín Blas,
Carlos de Cabo,
Celia Santos,
Elena Ruiz-Escribano,
Antonio García,
Luis Marín,
Lourdes Sáez,
José Luis Beato,
Ramón Rada,
Laura Navarro,
Caridad Sainz de Baranda,
Javier Solera,
L Sáez,
J Solera
Affiliations
Jesús Ontañón
Immunology Unit, Albacete General Hospital, c/ Hermanos Falcó 37, E-02008 Albacete, Spain
Research Department, Albacete General Hospital, c/ Hermanos Falcó 37, E-02008 Albacete, Spain; Corresponding author at: Departamento de Investigación, Hospital General de Albacete, c/ Hermanos Falcó 37, E-02008 Albacete, Spain.
Celia Santos
Internal Medicine Department, Albacete General Hospital, c/ Hermanos Falcó 37, E-02008 Albacete, Spain
Elena Ruiz-Escribano
Intensive Care Medicine Department, Albacete General Hospital c/ Hermanos Falcó 37, E-02008 Albacete, Spain
Internal Medicine Department, Albacete General Hospital, c/ Hermanos Falcó 37, E-02008 Albacete, Spain; Corresponding author at: Departamento de Investigación, Hospital General de Albacete, c/ Hermanos Falcó 37, E-02008 Albacete, Spain.
L Sáez
University of Castilla – La Mancha at Albacete, Faculty of Medicine, c/Almansa, 14, E-02008 Albacete, Spain
J Solera
University of Castilla – La Mancha at Albacete, Faculty of Medicine, c/Almansa, 14, E-02008 Albacete, Spain
Background: SARS-CoV-2 vaccines are an invaluable resource against COVID-19. Current vaccine shortage makes it necessary to prioritize distribution to the most appropriate segments of the population. Methods: This is a prospective cohort study of 63 health care workers (HCWs) from a General Hospital. We compared antibody responses to two doses of BNT162b2 mRNA COVID-19 vaccine between HCWs with previous SARS-CoV-2 infection (experienced HCWs) and HCWs without previous infection (naïve HCWs). Findings: Seven days after the first vaccine dose, HCWs with previous infection experienced a 126-fold increase in antibody levels (p50 AU). After the second dose, no significant increase in antibody levels was found in experienced HCWs, whereas in naïve HCWs, levels increased by 16-fold (p<0·001). Approximately two months post-vaccination, antibody levels were much lower in naïve HCWs compared to experienced HCWs (p<0·001). Interpretation: The study shows that at least ten months post-COVID-19 infection, the immune system is still capable of producing a rapid and powerful secondary antibody response following one single vaccine dose. Additionally, we found no further improvement in antibody response to the second dose in COVID-19 experienced HCWs. Nonetheless, two months later, antibody levels were still higher for experienced HCWs. These data suggest that immune memory persists in recovered individuals; therefore, the second dose of the COVID-19 vaccine in this group could be postponed until immunization of the remaining population is complete.
