Two doses of SARS-CoV-2 vaccination induce robust immune responses to emerging SARS-CoV-2 variants of concern

Abstract

The extent to which immune responses to natural infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and immunization with vaccines protect against variants of concern (VOC) is of increasing importance. Accordingly, here we analyse antibodies and T cells of a recently vaccinated, UK cohort, alongside those recovering from natural infection in early 2020. We show that neutralization of the VOC compared to a reference isolate of the original circulating lineage, B, is reduced: more profoundly against B.1.351 than for B.1.1.7, and in responses to infection or a single dose of vaccine than to a second dose of vaccine. Importantly, high magnitude T cell responses are generated after two vaccine doses, with the majority of the T cell response directed against epitopes that are conserved between the prototype isolate B and the VOC. Vaccination is required to generate high potency immune responses to protect against these and other emergent variants.

A Rapid Antibody Screening Haemagglutination Test for Predicting Immunity to Sars CoV-2 Variants of Concern

“…We developed HAT reagents for the VOC as they arose and con rmed a strong correlation between the alpha (R=0.79,p<0.0001) and beta (R=0.89,p<0.0001) in a UK set of naturally infected and vaccinated donors 22 (Figure 1F).…”

“…The Wuhan-like strain used in the microneutralisation and virus neutralisation assays in Bergen Norway was the clinical isolate; SARS-CoV-2/Human/NOR/Bergen1/2020 (GISAID accession ID EPI_ISL_541970) and at Public Health England, UK the isolate England/02/2020 20 (GISAID accession ID EPI_ISL_407073). At Oxford, UK 22 the Wuhan-like strain was Victoria/01/2020 (GenBank MT007544.…”

“…The MN titre was determined as the reciprocal of the serum dilution giving 50% inhibition of virus infectivity. Negative titres (<20) were assigned a value of 5 for calculation purposes.At Oxford, UK the detection of antibodies to the Wuhan-like VOC and (alpha, B.1.1.7.2 and beta, B.1.351) used the method described in22 . Brie y quadruplicate serial dilutions of serum were preincubated with appropriate SARS-CoV-2 for 30 minutes at room temperature, then Vero CCL81 cells were added and incubated at 37°C, 5% CO 2 for 2 hours.…”

Vaccinated Patients Admitted in ICU with Severe Pneumonia Due to SARS-CoV-2: A Multicenter Pilot Study

“…This pilot study aims to investigate the role of vaccination in severe cases and to explain the effectiveness of the vaccines, especially of vaccinated people admitted to the ICU. The main finding that we can deduct from this analysis is that most of the patients who have been admitted to the ICU having received a dose of the vaccine were not optimally vaccinated, understood as such to have received the recommended doses and wait 21 days after the administration of the last dose [7,8]. Recently, it has been documented that effectiveness after one dose of vaccine was notably lower among persons with the Delta variant which was predominant in our patient series [9], it seems less likely widespread escape from responses generated by vaccination with variant B.1.1.7 [10].…”

Immune response against SARS-CoV-2 variants: the role of neutralization assays

“… Vaccine Neutralization system Changes in S protein Reduction in neutralization titers (fold) Refs. BNT162b2 Lentivirus-based pseudovirus N501Y None 75 BNT162b2 Recombinant SARS-CoV-2 N501Y None 24 BNT162b2 Recombinant SARS-CoV-2 Selected – Alpha None 25 BNT162b2 Isolate Alpha 2 26 BNT162b2 Isolate Alpha 2.4 73 BNT162b2 Isolate Alpha 3.3 76 BNT162b2 Isolate Alpha None 48 BNT162b2 Isolate Alpha 2.6 77 mRNA-1273 Isolate Alpha None 48 mRNA-1273 Lentivirus-based pseudovirus Alpha 2.1 43 BNT162b2 VSV-based pseudovirus Alpha None 78 mRNA-1273 VSV-based pseudovirus Alpha None 28 BNT162b2 Isolate Beta 4.5 73 BNT162b2 Isolate Beta 10.3 …”