Persistence of Anti-SARS-CoV-2 Antibodies Six Months after Infection in an Outbreak with Five Hundred COVID-19 Cases in Borriana (Spain): A Prospective Cohort Study

Abstract

In March 2020, several mass gathering events were related to the Falles festival in Borriana (Spain), resulting in a 536 laboratory-confirmed COVID-19 cases outbreak among participants. This article estimates anti-SARS-CoV-2 antibodies persistence six months after and factors associated with antibody response. A prospective population-based cohort study was carried out by the Public Health Centre of Castellon and the Emergency and Clinical Analysis and Microbiology Services of Hospital de la Plana in Vila-real. In October 2020, a seroepidemiologic study was used to estimate the persistence of anti-SARS-CoV-2 antibodies against nucleocapsid protein (N) by an electrochemiluminescence immunoassay (ECLIA) was implemented. We enrolled 484 (90.2%) of the 536 members of the initial outbreak cohort and detected persistent antibodies in 479 (99%) without reinfection episodes. Five participants had a negative antibody test. Factors associated with a negative result were a lower body mass index (BMI), and less contact with other COVID-19 cases. Among the 469 participants with two ECLIA tests, 96 (20.5%) had an increase of antibodies and 373 (79.5%) a decline. Increased antibodies were associated with older age, higher BMI, more severe illness, and low current smokers. Our results show that after a COVID-19 infection, a high proportion of cases maintain detectable anti-SARS-CoV-2 antibodies.

ABO Blood Groups and the Incidence of Complications in COVID-19 Patients: A Population-Based Prospective Cohort Study

“…According to this study [56], a possibility is cross reactivity of the virus and the B antigen, and this increases antibody production, but the cause is unknown. In our previous study [26], the O group presented lower persistence of anti-SARS-CoV-2 antibodies than the non-O groups, but we found no difference in antibody levels between ABO blood groups.…”

“…After a COVID-19 outbreak in the Falles festival with several mass gathering events (MGEs) in Borriana (Spain) during March 2020 [25], we followed a population-based prospective cohort of patients until October 2020 [26] to estimate disease evolution and incidence of complications post-COVID-19, and its relationship with participants ABO blood group. The study was carried by the Public Health Center of Castelló, and the Emergency and Microbiology and Clinical Analysis Services of Hospital de la Plana Vila-real (Spain).…”

Complications Post-COVID-19 and Risk Factors among Patients after Six Months of a SARS-CoV-2 Infection: A Population-Based Prospective Cohort Study

“…We have not observed an association between BMI, obesity, regular exercise, or alcohol consumption and post-COVID-19 symptoms, in contrast with other studies [31,53]. In addition, high levels of anti-SARS-CoV-2 antibodies or their increase between June 2020 and October 2020 were not associated with complications, recovery, and return to the usual health [33], contrary to other studies [25,28,57]. However, attendance of MGEs, observing a person with a cough at MGEs, and contact with a COVID-19 patient were associated with complications, inferior recovery, and less frequent return to usual health.…”

“…In March 2020 a COVID-19 outbreak took place during the mass gathering events (MGEs) of the Falles festival in Borriana, a city of 34,000 inhabitants, in the Castellon province, Valencia Community (Spain), with 536 laboratory-confirmed cases of COVID-19 [32]. In October 2020 a population-based prospective cohort study of 536 COVID-19 patients was performed by the Public Health Center of Castelló de la Plana, and the Emergency and Microbiology and Clinical Analysis Services of Hospital de la Plana Vila-real [33].…”

“…In summary, the sero-surveys included determinations of anti-SARS-CoV-2 N-antibodies in June and October 2020 with a flow chart of the study, and ABO blood groups and vitamin D status in October 2020. The sero-survey results were subject of two previous publications [33,34], and are no further discussed in the current manuscript. Health staff of Hospital La Plana Vila-real, and several health centers (Borriana, Vila-real, Onda, and Vall D'Uixo) performed the telephone interviews.…”