RESUMO
Immune imprinting is a phenomenon in which prior antigenic experiences influence responses to subsequent infection or vaccination1,2. The effects of immune imprinting on serum antibody responses after boosting with variant-matched SARS-CoV-2 vaccines remain uncertain. Here we characterized the serum antibody responses after mRNA vaccine boosting of mice and human clinical trial participants. In mice, a single dose of a preclinical version of mRNA-1273 vaccine encoding Wuhan-1 spike protein minimally imprinted serum responses elicited by Omicron boosters, enabling generation of type-specific antibodies. However, imprinting was observed in mice receiving an Omicron booster after two priming doses of mRNA-1273, an effect that was mitigated by a second booster dose of Omicron vaccine. In both SARS-CoV-2-infected and uninfected humans who received two Omicron-matched boosters after two or more doses of the prototype mRNA-1273 vaccine, spike-binding and neutralizing serum antibodies cross-reacted with Omicron variants as well as more distantly related sarbecoviruses. Because serum neutralizing responses against Omicron strains and other sarbecoviruses were abrogated after pre-clearing with Wuhan-1 spike protein, antibodies induced by XBB.1.5 boosting in humans focus on conserved epitopes targeted by the antecedent mRNA-1273 primary series. Thus, the antibody response to Omicron-based boosters in humans is imprinted by immunizations with historical mRNA-1273 vaccines, but this outcome may be beneficial as it drives expansion of cross-neutralizing antibodies that inhibit infection of emerging SARS-CoV-2 variants and distantly related sarbecoviruses.
Assuntos
Anticorpos Neutralizantes , Anticorpos Antivirais , Vacinas contra COVID-19 , COVID-19 , Imunização Secundária , SARS-CoV-2 , Vacinas de mRNA , Adulto , Animais , Feminino , Humanos , Masculino , Camundongos , Vacina de mRNA-1273 contra 2019-nCoV/administração & dosagem , Vacina de mRNA-1273 contra 2019-nCoV/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/imunologia , Anticorpos Antivirais/sangue , China , COVID-19/imunologia , COVID-19/prevenção & controle , COVID-19/virologia , Vacinas contra COVID-19/administração & dosagem , Vacinas contra COVID-19/genética , Vacinas contra COVID-19/imunologia , Reações Cruzadas/imunologia , Epitopos de Linfócito B/imunologia , Vacinas de mRNA/administração & dosagem , Vacinas de mRNA/genética , Vacinas de mRNA/imunologia , SARS-CoV-2/classificação , SARS-CoV-2/genética , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/genética , VacinaçãoRESUMO
BACKGROUND: Monovalent Omicron XBB.1.5-containing vaccines were approved for coronavirus disease 2019 (COVID-19) 2023-2024 immunizations. METHODS: This ongoing, open-label, phase 2/3 study evaluated messenger RNA (mRNA)-1273.815 monovalent (50-µg Omicron XBB.1.5 spike mRNA) and mRNA-1273.231 bivalent (25-µg each Omicron XBB.1.5 and BA.4/BA.5 spike mRNAs) vaccines, administered as fifth doses to adults who previously received primary series, third doses of an original mRNA COVID-19 vaccine, and fourth doses of an Omicron BA.4/BA.5 bivalent vaccine. Interim safety and immunogenicity 29 days after vaccination are reported. RESULTS: Participants (randomized 1:1) received 50-µg of mRNA-1273.815 (n = 50) or mRNA-1273.231 (n = 51); median intervals (interquartile range) from prior BA.4/BA.5 bivalent doses were 8.2 (8.1-8.3) and 8.3 (8.1-8.4) months, respectively. Fold increases in neutralizing antibody (nAb) against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants from prebooster nAb levels were numerically higher against XBB.1.5, XBB.1.16, EG.5.1, BA.2.86, and JN.1 than BA.4/BA.5, BQ.1.1, or D614G on day 29. Monovalent vaccine also cross-neutralized FL.1.5.1, EG.5.1, BA.2.86, HK.3.1, HV.1, and JN.1 variants in a participant subset (n = 20) 15 days after vaccination. Reactogenicity was similar to that of mRNA-1273 vaccines. CONCLUSIONS: XBB.1.5-containing mRNA-1273 vaccines elicit robust, diverse nAb responses against more recent SARS-CoV-2 variants, including JN.1, supporting the XBB.1.5-spike update for COVID-19 vaccines.
Assuntos
Vacina de mRNA-1273 contra 2019-nCoV , Anticorpos Neutralizantes , Anticorpos Antivirais , Vacinas contra COVID-19 , COVID-19 , Imunogenicidade da Vacina , SARS-CoV-2 , Humanos , COVID-19/prevenção & controle , COVID-19/imunologia , Adulto , Feminino , SARS-CoV-2/imunologia , SARS-CoV-2/genética , Vacina de mRNA-1273 contra 2019-nCoV/imunologia , Anticorpos Antivirais/sangue , Masculino , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/imunologia , Pessoa de Meia-Idade , Vacinas contra COVID-19/imunologia , Vacinas contra COVID-19/efeitos adversos , Vacinas contra COVID-19/administração & dosagem , Vacinação , Adulto Jovem , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/genética , IdosoRESUMO
Background: Characterizing the antibody epitope profiles of messenger RNA (mRNA)-based vaccines against SARS-CoV-2 can aid in elucidating the mechanisms underlying the antibody-mediated immune responses elicited by these vaccines. Methods: This study investigated the distinct antibody epitopes toward the SARS-CoV-2 spike (S) protein targeted after a two-dose primary series of mRNA-1273 followed by a booster dose of mRNA-1273 or a variant-updated vaccine among serum samples from clinical trial adult participants. Results: Multiple S-specific epitopes were targeted after primary vaccination; while signal decreased over time, a booster dose after >6 months largely revived waning antibody signals. Epitope identity also changed after booster vaccination in some subjects, with four new S-specific epitopes detected with stronger signals after boosting than with primary vaccination. Notably, the strength of antibody responses after booster vaccination differed by the exact vaccine formulation, with variant-updated mRNA-1273.211 and mRNA-1273.617.2 booster formulations inducing significantly stronger S-specific signals than a mRNA-1273 booster. Conclusion: Overall, these results identify key S-specific epitopes targeted by antibodies induced by mRNA-1273 primary and variant-updated booster vaccination.
Assuntos
Vacina de mRNA-1273 contra 2019-nCoV , Vacinas contra COVID-19 , Adulto , Humanos , Anticorpos , Vacinação , Epitopos , RNA Mensageiro/genética , SARS-CoV-2 , Vacinas de mRNARESUMO
Although vaccines have reduced COVID-19 disease burden, their efficacy in helminth infection endemic areas is not well characterized. We evaluated the impact of infection by Heligmosomoides polygyrus bakeri (Hpb), a murine intestinal hookworm, on the efficacy of an mRNA vaccine targeting the Wuhan-1 spike protein of SARS-CoV-2. Although immunization generated similar B cell responses in Hpb-infected and uninfected mice, polyfunctional CD4+ and CD8+ T cell responses were markedly reduced in Hpb-infected mice. Hpb-infected and mRNA vaccinated mice were protected against the ancestral SARS-CoV-2 strain WA1/2020, but control of lung infection was diminished against an Omicron variant compared to animals immunized without Hpb infection. Helminth mediated suppression of spike-specific CD8+ T cell responses occurred independently of STAT6 signaling, whereas blockade of IL-10 rescued vaccine-induced CD8+ T cell responses. In mice, intestinal helminth infection impairs vaccine induced T cell responses via an IL-10 pathway and compromises protection against antigenically shifted SARS-CoV-2 variants.