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1.
Nature ; 607(7918): 356-359, 2022 07.
Article in English | MEDLINE | ID: covidwho-1830078

ABSTRACT

The extent to which Omicron infection1-9, with or without previous vaccination, elicits protection against the previously dominant Delta (B.1.617.2) variant is unclear. Here we measured the neutralization capacity against variants of severe acute respiratory syndrome coronavirus 2 in 39 individuals in South Africa infected with the Omicron sublineage BA.1 starting at a median of 6 (interquartile range 3-9) days post symptom onset and continuing until last follow-up sample available, a median of 23 (interquartile range 19-27) days post symptoms to allow BA.1-elicited neutralizing immunity time to develop. Fifteen participants were vaccinated with Pfizer's BNT162b2 or Johnson & Johnson's Ad26.CoV2.S and had BA.1 breakthrough infections, and 24 were unvaccinated. BA.1 neutralization increased from a geometric mean 50% focus reduction neutralization test titre of 42 at enrolment to 575 at the last follow-up time point (13.6-fold) in vaccinated participants and from 46 to 272 (6.0-fold) in unvaccinated participants. Delta virus neutralization also increased, from 192 to 1,091 (5.7-fold) in vaccinated participants and from 28 to 91 (3.0-fold) in unvaccinated participants. At the last time point, unvaccinated individuals infected with BA.1 had low absolute levels of neutralization for the non-BA.1 viruses and 2.2-fold lower BA.1 neutralization, 12.0-fold lower Delta neutralization, 9.6-fold lower Beta variant neutralization, 17.9-fold lower ancestral virus neutralization and 4.8-fold lower Omicron sublineage BA.2 neutralization relative to vaccinated individuals infected with BA.1. These results indicate that hybrid immunity formed by vaccination and Omicron BA.1 infection should be protective against Delta and other variants. By contrast, infection with Omicron BA.1 alone offers limited cross-protection despite moderate enhancement.


Subject(s)
Antibodies, Neutralizing , Antibodies, Viral , COVID-19 Vaccines , COVID-19 , Cross Protection , SARS-CoV-2 , Vaccination , Ad26COVS1/immunology , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , BNT162 Vaccine/immunology , COVID-19/immunology , COVID-19/prevention & control , COVID-19/virology , COVID-19 Vaccines/immunology , Cross Protection/immunology , Humans , SARS-CoV-2/classification , SARS-CoV-2/genetics , SARS-CoV-2/immunology , Vaccination/statistics & numerical data
2.
Cell ; 185(9): 1549-1555.e11, 2022 04 28.
Article in English | MEDLINE | ID: covidwho-1748149

ABSTRACT

The rapid spread of the SARS-CoV-2 Omicron (B.1.1.529) variant, including in highly vaccinated populations, has raised important questions about the efficacy of current vaccines. In this study, we show that the mRNA-based BNT162b2 vaccine and the adenovirus-vector-based Ad26.COV2.S vaccine provide robust protection against high-dose challenge with the SARS-CoV-2 Omicron variant in cynomolgus macaques. We vaccinated 30 macaques with homologous and heterologous prime-boost regimens with BNT162b2 and Ad26.COV2.S. Following Omicron challenge, vaccinated macaques demonstrated rapid control of virus in bronchoalveolar lavage, and most vaccinated animals also controlled virus in nasal swabs. However, 4 vaccinated animals that had moderate Omicron-neutralizing antibody titers and undetectable Omicron CD8+ T cell responses failed to control virus in the upper respiratory tract. Moreover, virologic control correlated with both antibody and T cell responses. These data suggest that both humoral and cellular immune responses contribute to vaccine protection against a highly mutated SARS-CoV-2 variant.


Subject(s)
Ad26COVS1/immunology , BNT162 Vaccine/immunology , COVID-19 , Macaca , SARS-CoV-2 , Ad26COVS1/administration & dosage , Animals , Antibodies, Neutralizing , Antibodies, Viral , BNT162 Vaccine/administration & dosage , COVID-19/immunology , COVID-19/prevention & control , T-Lymphocytes/immunology
3.
Sci Transl Med ; 14(638): eabm4996, 2022 03 30.
Article in English | MEDLINE | ID: covidwho-1705843

ABSTRACT

Ad26.COV2.S has demonstrated durability and clinical efficacy against symptomatic COVID-19 in humans. In this study, we report the correlates of durability of humoral and cellular immune responses in 20 rhesus macaques immunized with single-shot Ad26.COV2.S and the immunogenicity of a booster shot at 8 to 10 months after the initial immunization. Ad26.COV2.S elicited durable binding and neutralizing antibodies as well as memory B cells and long-lived bone marrow plasma cells. Innate immune responses and bone marrow plasma cell responses correlated with durable antibody responses. After Ad26.COV2.S boost immunization, binding and neutralizing antibody responses against multiple SARS-CoV-2 variants increased 31- to 69-fold and 23- to 43-fold, respectively, compared with preboost concentrations. Antigen-specific B cell and T cell responses also increased substantially after the boost immunization. Boosting with a modified Ad26.COV2.S.351 vaccine expressing the SARS-CoV-2 spike protein from the beta variant led to largely comparable responses with slightly higher beta- and omicron-specific humoral immune responses. These data demonstrate that a late boost with Ad26.COV2.S or Ad26.COV2.S.351 resulted in a marked increase in humoral and cellular immune responses that were highly cross-reactive across multiple SARS-CoV-2 variants in rhesus macaques.


Subject(s)
Ad26COVS1 , COVID-19 , Immunity, Humoral , Immunization, Secondary , SARS-CoV-2 , Ad26COVS1/immunology , Animals , Antibodies, Neutralizing , Antibodies, Viral , COVID-19/prevention & control , Macaca mulatta , Spike Glycoprotein, Coronavirus
4.
Cell ; 185(5): 847-859.e11, 2022 03 03.
Article in English | MEDLINE | ID: covidwho-1650711

ABSTRACT

We address whether T cell responses induced by different vaccine platforms (mRNA-1273, BNT162b2, Ad26.COV2.S, and NVX-CoV2373) cross-recognize early SARS-CoV-2 variants. T cell responses to early variants were preserved across vaccine platforms. By contrast, significant overall decreases were observed for memory B cells and neutralizing antibodies. In subjects ∼6 months post-vaccination, 90% (CD4+) and 87% (CD8+) of memory T cell responses were preserved against variants on average by AIM assay, and 84% (CD4+) and 85% (CD8+) preserved against Omicron. Omicron RBD memory B cell recognition was substantially reduced to 42% compared with other variants. T cell epitope repertoire analysis revealed a median of 11 and 10 spike epitopes recognized by CD4+ and CD8+ T cells, with average preservation > 80% for Omicron. Functional preservation of the majority of T cell responses may play an important role as a second-level defense against diverse variants.


Subject(s)
COVID-19 Vaccines/immunology , Memory B Cells/immunology , Memory T Cells/immunology , SARS-CoV-2/immunology , Ad26COVS1/administration & dosage , Ad26COVS1/immunology , BNT162 Vaccine/administration & dosage , BNT162 Vaccine/immunology , CD4-Positive T-Lymphocytes/immunology , CD4-Positive T-Lymphocytes/metabolism , CD8-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/metabolism , COVID-19/pathology , COVID-19/prevention & control , COVID-19/virology , COVID-19 Vaccines/administration & dosage , Epitopes/immunology , Epitopes, T-Lymphocyte/immunology , Humans , Memory B Cells/metabolism , Memory T Cells/metabolism , SARS-CoV-2/isolation & purification , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/immunology , Vaccination
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