Breakthrough infections with the omicron and delta variants of SARS-CoV-2 result in similar re-activation of vaccine-induced immunity

Abstract

Background: The Omicron variant of SARS-CoV-2 is now overtaking the Delta variant in many countries. Results showing that sera from double vaccinated individuals have minimal neutralizing activity against Omicron may indicate that the higher rate of transmission is due to evasion from vaccine-induced immunity. However, there is little information about activation of recall responses to Omicron in vaccinated individuals. Methods: We measured inflammatory mediators, antibodies to the SARS-CoV-2 spike and nucleocapsid proteins, and spike peptide-induced release of interferon gamma in whole blood in 51 vaccinated individuals infected with Omicron, in 14 infected with Delta, and in 18 healthy controls. The median time points for the first and second samples were 7 and 14 days after symptom onset, respectively. Findings: Infection with Omicron or Delta led to a rapid and similar increase in antibodies to the SARS-CoV-2 spike and nucleocapsid proteins and spike peptide-induced interferon gamma in whole blood. Both the Omicron and the Delta infected patients had a mild and transient increase in inflammatory parameters. Interpretation: The results suggest that vaccine-induced immunological memory yields similar coverage for the Omicron and Delta variants.

Titers of antibodies the receptor-binding domain (RBD) of ancestral SARS-CoV-2 are predictive for levels of neutralizing antibodies to multiple variants

“…2g-l ). The samples are therefore likely to be from SARS-CoV-2/vaccine naive individuals infected with Omicron 30 . Overall, signals measured for binding of antibodies to RBD from Omicron were weaker than those measured for RBDs from other variants ( Fig.…”

Titers of antibodies the receptor-binding domain (RBD) of ancestral SARS-CoV-2 are predictive for levels of neutralizing antibodies to multiple variants

“…2gl). The samples are therefore likely to be from SARS-CoV-2/vaccine naive individuals infected with Omicron (32). Overall, signals measured for binding of antibodies to RBD from Omicron BA1 were weaker than those measured for RBDs from other variants (Fig.…”

Prevalence of antibodies against SARS‐CoV‐2 in the Norwegian population, August 2021

“… 35 Lower levels of antibodies against nucleocapsid/lower rates of seroconversion against nucleocapsid have also been reported in COVID‐19 vaccinated individuals with breakthrough infections than after infection of unvaccinated individuals. 21 , 23 , 36 Perhaps an earlier control of SARS‐CoV‐2 by the immune system in children or vaccinated individuals may result in a weaker antibody response against nucleocapsid. 21 , 36 , 37 , 38 , 39 , 40 The antibody assay can also influence detection of anti‐N antibodies.…”

“… 21 , 23 , 36 Perhaps an earlier control of SARS‐CoV‐2 by the immune system in children or vaccinated individuals may result in a weaker antibody response against nucleocapsid. 21 , 36 , 37 , 38 , 39 , 40 The antibody assay can also influence detection of anti‐N antibodies. 33 Here, lack of nucleocapsid antibodies in some of the seropositive samples from children were confirmed by a second method.…”