Effect of previous SARS-CoV-2 infection on humoral and T-cell responses to single-dose BNT162b2 vaccine

Abstract

Attendance in education and early years settings during the coronavirus (COVID-19) outbreak. Nov 24, 2020. https://exploreeducation-statistics.service.gov.uk/findstatistics/attendance-in-education-and-earlyyears-settings-during-the-coronavirus-covid-19-outbreak/2020-week-47 (accessed March 9, 2021). 3 Jeffreys B. More children in England missing school over Covid-19. Oct 27, 2020. https:// www.bbc.co.uk/news/education-54695618 (accessed March 9, 2021). 4 Hyde Z. COVID-19, children and schools: overlooked and at risk. Med J Aust 2021; 214: 190-91.e1. 5 Hyde Z. Difference in SARS-CoV-2 attack rate between children and adults may reflect bias.

Longitudinal determination of mRNA-vaccination induced strongly binding SARS-CoV-2 IgG antibodies in a cohort of Romanian healthcare workers

“…Our results show a robust humoral immune response that mounts gradually after the first BNT162b2 vaccine dose for the group previously uninfected with SARS-CoV-2, and a much stronger immune response within 7-14 days after the first dose for the previously infected group, in line with recent data from other cohorts of healthcare workers. 17 For the previously infected group, the booster dose slightly elevates the SARS-CoV-2 anti-S1 antibody levels further, and we do not see the levels of the two groups converging at the beginning of Period 2 of our study. It remains to be seen if antibody level kinetics remains significantly different between the two groups over the period of several months.…”

“…Currently approved vaccines in the European Union contain instructions for cells to synthesize the SARS-CoV-2 spike protein, therefore the immune system will produce anti-SARS-CoV-2 spike antibodies, [14][15][16] while vaccine candidates that contain the full-length spike protein trimer are also in the pipeline. Several recent studies show a significant difference between post-vaccination immune response of previously infected individuals compared to uninfected vaccinated individuals, [17][18][19] as the former group mounts a quick immune response within the first two weeks of the first vaccine dose, while the antibody titers of the non-infected group will be on average lower than those of the first group even 10 days after the second dose. 18 However, much more data is needed to better understand the dynamics of post-vaccination antibody production in these two groups.…”

First dose mRNA vaccination is sufficient to reactivate immunological memory to SARS-CoV-2 in ex COVID-19 subjects

“…Indeed, in most countries individuals who recovered from SARS-CoV-2 infection are not excluded from COVID-19 vaccination, and they commonly follow two-doses vaccination schedule [13-14]. However, differently from naïve individuals, these data suggest that one single injection may be sufficient to protect ex COVID-19 subjects in accordance with emerging data [15-16]. We also cannot exclude that the second jab might even be detrimental in this context, leading to a functional exhaustion of spike-specific lymphocytes [17].…”

COVID-19 vaccination: the reality after clinical trials

“…Las investigaciones llevadas a cabo muestran que las personas con infección previa por SARS-CoV-2 tienen en su mayoría anticuerpos y que los niveles se multiplican hasta 20 veces tras recibir una dosis de la vacuna [8,9]. Esto indicaría que con esos niveles no se precisa una segunda dosis [10]. Esta evidencia se ha utilizado como base para abogar por una sola dosis en estas circunstancias [11].…”