Antibody correlates of protection from SARS-CoV-2 reinfection prior to vaccination: A nested case-control within the SIREN study

• DOI: 10.1016/j.jinf.2022.09.004
• Publication Date: 2022-09-09T09:31:01Z
• Authors: Ana Atti; Ferdinando Insalata; Edward J Carr; Ashley D Otter; Javier Castillo-O...; Mary Wu; Ruth Harvey; Michael Howell; Andrew Chan; Jonathan Lyall; Nigel Temperton; Diego Cantoni; Kelly da Costa; Angalee Nadesalingam; Andrew Taylor-Kerr; Nipunadi Hettiara...; Caio Tranquillini; Jacqueline Hewson; Michelle J Cole; Sarah Foulkes; Katie Munro; Edward J M Monk; Iain D Milligan; Ezra Linley; Meera A Chand; Colin S Brown; Jasmin Islam; Amanda Semper; Andre Charlett; Jonathan L Heeney; Rupert Beale; Maria Zambon; Susan Hopkins; Tim Brooks; Victoria Hall
• Keywords: Conditional logistic regression; Antibody response

ObjectivesTo investigate serological differences between SARS-CoV-2 reinfection cases and contemporary controls, to identify antibody correlates of protection against reinfection.MethodsWe performed a case-control study, comparing with singly infected individuals pre-vaccination, matched by gender, age, region timing first infection. Serum samples were tested for anti-SARS-CoV-2 spike (anti-S), nucleocapsid (anti-N), live virus microneutralisation (LV-N) pseudovirus (PV-N). Results analysed using fixed effect linear regression fitted into conditional logistic models.ResultsWe identified 23 92 controls. First infections occurred before November 2020; reinfections February 2021, pre-vaccination. Anti-S levels, LV-N PV-N titres significantly lower among cases; no difference was found anti-N levels. Increasing anti-S levels associated reduced risk (OR 0·63, CI 0·47-0·85), but association 0·88, 0·73-1·05). Titres >40 correlated Wuhan 0·02, 0·001–0·31) Alpha 0·07, 0·009–0·62). For PV-N, >100 0·14, 0·03–0·64) (0·06, 0·008–0·40).ConclusionsBefore vaccination, directly titres, not Detectable sufficient protection, whilst required protective effect.Trial registration numberISRCTN11041050