[COVID-19 vaccination at the University of Alicante (Spain): detection of neutralizing antibodies against SARS-CoV-2 by rapid serological test, a cross-sectional study]. / Vacunación contra la COVID-19 en la Universidad de Alicante (España): detección de anticuerpos neutralizantes frente al sars-CoV-2 mediante test serológico rápido, un estudio transversal.

OBJECTIVE: Neutralizing antibodies against SARS-CoV-2 have shown to be an effective tool for the analysis of the immunity generated against COVID-19. Numerous seroprevalence studies carried out in different groups have made it possible to draw a global map of vaccination coverage through the use of rapid lateral flow immunochromatography serological tests for clinical and epidemiological purposes. The objective of our study was to determine the degree of immunity against SARS-CoV-2 associated with the presence of neutralizing antibodies in administrative staff, teachers and students at the University of Alicante by means of a rapid serological test and to learn about their experience with vaccination against COVID-19. METHODS: A cross-sectional epidemiological study was designed, based on the prevalence of antibodies against the S protein (spike) of SARS-CoV-2. A total of 888 people participated. The study was carried out with a single test (July 6 to July 22, 2021). Using logistic regression, adjusted Odds Ratios were calculated according to sex, age, type of vaccine, number of vaccine doses received, complete vaccination schedule, and having had COVID-19. RESULTS: The vaccines received mostly were Vaxzevria® and Comirnaty®, with 73.3% between both, although 67.2% presented a complete regimen. The results of the OJABIO rapid neutralizing antibody test gave a positive result in 61.4% of the sample. There was a high association between the variables COVID-19 infection, two doses of vaccine, Spikevax® or Comirnaty® vaccine, and eighteen/twenty-nine years old group with a positive result on the OJABIO test. A total of 712 subjects answered the parallel survey (80%) on adverse effects and preferences between the different vaccines against COVID-19. CONCLUSIONS: The vaccination status against COVID-19 in the university community after six months of the start of national immunization strategies reflects low coverage despite the excellent willingness to get vaccinated. Neutralizing antibodies (NAb) rapid tests can be useful to guide immunization strategies and decide when to administer new booster doses.

OBJECTIVE: Los anticuerpos neutralizantes frente al SARS-CoV-2 han resultado una herramienta eficaz para el análisis de la inmunidad generada frente a la COVID-19. Numerosos estudios de seroprevalencia realizados en diferentes colectivos han permitido trazar un mapa global sobre la cobertura vacunal mediante el uso de pruebas serológicas rápidas de inmunocromatografía de flujo lateral con fines clínicos y epidemiológicos. El objetivo de nuestro estudio fue determinar el grado de inmunidad frente al SARS-CoV-2 asociado a la presencia de anticuerpos neutralizantes en personal administrativo, docentes y estudiantes de la Universidad de Alicante, mediante un test serológico rápido, así como conocer su experiencia sobre la vacunación frente a la COVID-19. METHODS: Se diseñó un estudio epidemiológico, transversal, basado en la prevalencia de anticuerpos frente a la proteína S (espícula o Spike) del SARS-CoV-2. Participaron un total de 888 personas. El estudio se llevó a cabo con un único test (6 de julio a 22 de julio de 2021). Mediante regresión logística se calcularon Odds Ratios ajustadas según sexo, edad, tipo de vacuna, número de dosis de vacuna recibidas, pauta completa de vacunación y haber padecido la COVID-19. RESULTS: Las vacunas recibidas mayoritariamente fueron Vaxzevria® y Comirnaty®, con un 73,3% entre ambas; el 67,2% presentó pauta completa. Los resultados del test rápido de anticuerpos neutralizantes OJABIO dieron un resultado positivo en el 61,4% de la muestra. La posibilidad de un resultado positivo en el test OJABIO estuvo fuertemente asociada a haber padecido la COVID-19, haber recibido dos dosis, estar vacunado con Spikevax® o Comirnaty® o pertenecer al grupo de dieciocho a veintinueve años. Un total de 712 sujetos respondieron a un cuestionario (80%) paralelo sobre los efectos adversos y las preferencias entre las distintas vacunas contra la COVID-19. CONCLUSIONS: El estado de vacunación frente a la COVID-19 en la comunidad universitaria a los seis meses de la puesta en marcha de las estrategias nacionales de inmunización refleja una baja cobertura asociada, a pesar de la excelente predisposición a vacunarse. Los test rápidos de anticuerpos neutralizantes (AcN) pueden ser de utilidad para orientar las estrategias de inmunización y para decidir el momento de administrar nuevas dosis de refuerzo.

Detection of Neutralizing Antibodies against SARS-CoV-2 Post-Vaccination in Health Care Workers of a Large Tertiary Hospital in Spain by Using a Rapid Test LFIC and sVNT-ELISA.

The presence of neutralizing antibodies (NAbs) against SARS-CoV-2 represent a surrogate marker of immunologic protection in populations at high risk of infection such as healthcare workers caring for hospitalized patients with COVID-19. As recommended by CDC and the European CDC, the use of rapid diagnostic tests during population-based evaluations offers an opportunity to identify individuals with serologic evidence of natural infection or who have undergone vaccination. We carried out a cross-sectional study to assess the presence of neutralizing antibodies against SARS-CoV-2 among medical providers at an intensive care unit of a large referral hospital in Alicante, Spain. In addition, we tested for the presence of neutralizing antibodies compared to serum of uninfected individuals from a Biobank. We were also interested in evaluating the use of a rapid lateral flow immunochromatography (LFIC) test against a surrogate ELISA viral neutralization test (sVNT). This rapid test demonstrated a specificity of 1.000 95% CI (0.91-1.00) and the sensitivity of 0.987 95% CI (0.93-1.00). The negative predictive value was 95%. After six months, this rapid test demonstrated that those immunized with two doses of BioNTech/Pfizer vaccine, maintained optimal levels of neutralizing antibodies. We concluded that all Health Care Workers develop NAbs and the use of this rapid immunochromatographic test represents a potential tool to be used in population-based studies to detect serological antibody responses to vaccination. Vaccination policies could benefit from this tool to assess additional doses of vaccine or boosters among high-risk populations.