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1.
Open Forum Infect Dis ; 9(7): ofac227, 2022 Jul.
Article in English | MEDLINE | ID: covidwho-1931886

ABSTRACT

The emergence of severe acute respiratory syndrome coronavirus 2 variants that have greater transmissibility and resistance to neutralizing antibodies has increased the incidence of breakthrough infections. We show that breakthrough infection increases neutralizing antibody titers to varying degrees depending on the nature of the breakthrough variant and the number of vaccine doses previously administered. Omicron breakthrough infection resulted in neutralizing antibody titers that were the highest across all groups, particularly against Omicron.

2.
J Exp Med ; 219(8)2022 Aug 01.
Article in English | MEDLINE | ID: covidwho-1922149

ABSTRACT

The single-dose Ad.26.COV.2 (Janssen) vaccine elicits lower levels of neutralizing antibodies and shows more limited efficacy in protection against infection than either of the two available mRNA vaccines. In addition, Ad.26.COV.2 has been less effective in protection against severe disease during the Omicron surge. Here, we examined the memory B cell response to single-dose Ad.26.COV.2 vaccination. Compared with mRNA vaccines, Ad.26.COV.2 recipients had significantly lower numbers of RBD-specific memory B cells 1.5 or 6 mo after vaccination. Despite the lower numbers, the overall quality of the memory B cell responses appears to be similar, such that memory antibodies elicited by both vaccine types show comparable neutralizing potency against SARS-CoV-2 Wuhan-Hu-1, Delta, and Omicron BA.1 variants. The data help explain why boosting Ad.26.COV.2 vaccine recipients with mRNA vaccines is effective and why the Ad26.COV2.S vaccine can maintain some protective efficacy against severe disease during the Omicron surge.


Subject(s)
COVID-19 , Vaccines , Ad26COVS1 , Antibodies, Neutralizing , COVID-19/prevention & control , Humans , SARS-CoV-2 , mRNA Vaccines
3.
J Exp Med ; 219(9)2022 Sep 05.
Article in English | MEDLINE | ID: covidwho-1922148

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to be a global problem in part because of the emergence of variants of concern that evade neutralization by antibodies elicited by prior infection or vaccination. Here we report on human neutralizing antibody and memory responses to the Gamma variant in a cohort of hospitalized individuals. Plasma from infected individuals potently neutralized viruses pseudotyped with Gamma SARS-CoV-2 spike protein, but neutralizing activity against Wuhan-Hu-1-1, Beta, Delta, or Omicron was significantly lower. Monoclonal antibodies from memory B cells also neutralized Gamma and Beta pseudoviruses more effectively than Wuhan-Hu-1. 69% and 34% of Gamma-neutralizing antibodies failed to neutralize Delta or Wuhan-Hu-1. Although Class 1 and 2 antibodies dominate the response to Wuhan-Hu-1 or Beta, 54% of antibodies elicited by Gamma infection recognized Class 3 epitopes. The results have implications for variant-specific vaccines and infections, suggesting that exposure to variants generally provides more limited protection to other variants.


Subject(s)
COVID-19 , SARS-CoV-2 , Antibodies, Neutralizing , Antibodies, Viral , Antibody Formation , Humans , Membrane Glycoproteins/metabolism , Neutralization Tests , Spike Glycoprotein, Coronavirus , Viral Envelope Proteins
4.
Open forum infectious diseases ; 2022.
Article in English | EuropePMC | ID: covidwho-1863910

ABSTRACT

The emergence of SARS-CoV-2 variants that have greater transmissibility and resistance to neutralizing antibodies has increased the incidence of breakthrough infections. We show that breakthrough infection increases neutralizing antibody titers to varying degrees depending on the nature of the breakthrough variant and the number of vaccine doses previously administered. Omicron breakthrough infection resulted in neutralizing antibody titers that were the highest across, particularly against omicron.

5.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-336206

ABSTRACT

The SARS-CoV-2 pandemic prompted a global vaccination effort and the development of numerous COVID-19 vaccines at an unprecedented scale and pace. As a result, current COVID- 19 vaccination regimens comprise diverse vaccine modalities, immunogen combinations and dosing intervals. Here, we compare vaccine-specific antibody and memory B cell responses following two-dose mRNA, single-dose Ad26.COV2.S and two-dose ChAdOx1 or combination ChAdOx1/mRNA vaccination. Plasma neutralizing activity as well as the magnitude, clonal composition and antibody maturation of the RBD-specific memory B cell compartment showed substantial differences between the vaccination regimens. While individual monoclonal antibodies derived from memory B cells exhibited similar binding affinities and neutralizing potency against Wuhan-Hu-1 SARS-CoV-2, there were significant differences in epitope specificity and neutralizing breadth against viral variants of concern. Although the ChAdOx1 vaccine was inferior to mRNA and Ad26.COV2.S in several respects, biochemical and structural analyses revealed enrichment in a subgroup of memory B cell neutralizing antibodies with distinct RBD-binding properties resulting in remarkable potency and breadth.

6.
Nature ; 607(7917): 128-134, 2022 07.
Article in English | MEDLINE | ID: covidwho-1805634

ABSTRACT

The Omicron variant of SARS-CoV-2 infected many vaccinated and convalescent individuals1-3. Despite the reduced protection from infection, individuals who received three doses of an mRNA vaccine were highly protected from more serious consequences of infection4. Here we examine the memory B cell repertoire in a longitudinal cohort of individuals receiving three mRNA vaccine doses5,6. We find that the third dose is accompanied by an increase in, and evolution of, receptor-binding domain (RBD)-specific memory B cells. The increase is due to expansion of memory B cell clones that were present after the second dose as well as the emergence of new clones. The antibodies encoded by these cells showed significantly increased potency and breadth when compared with antibodies obtained after the second dose. Notably, the increase in potency was especially evident among newly developing clones of memory cells, which differed from persisting clones in targeting more conserved regions of the RBD. Overall, more than 50% of the analysed neutralizing antibodies in the memory compartment after the third mRNA vaccine dose neutralized the Omicron variant. Thus, individuals receiving three doses of an mRNA vaccine have a diverse memory B cell repertoire that can respond rapidly and produce antibodies capable of clearing even diversified variants such as Omicron. These data help to explain why a third dose of a vaccine that was not specifically designed to protect against variants is effective against variant-induced serious disease.


Subject(s)
COVID-19 Vaccines , COVID-19 , Immunization, Secondary , Memory B Cells , SARS-CoV-2 , mRNA Vaccines , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19/immunology , COVID-19/prevention & control , COVID-19/virology , COVID-19 Vaccines/administration & dosage , COVID-19 Vaccines/immunology , Humans , Memory B Cells/immunology , RNA, Messenger/genetics , SARS-CoV-2/genetics , SARS-CoV-2/immunology , mRNA Vaccines/administration & dosage , mRNA Vaccines/immunology
7.
Immunity ; 55(6): 998-1012.e8, 2022 06 14.
Article in English | MEDLINE | ID: covidwho-1778212

ABSTRACT

SARS-CoV-2 infection or vaccination produces neutralizing antibody responses that contribute to better clinical outcomes. The receptor-binding domain (RBD) and the N-terminal domain (NTD) of the spike trimer (S) constitute the two major neutralizing targets for antibodies. Here, we use NTD-specific probes to capture anti-NTD memory B cells in a longitudinal cohort of infected individuals, some of whom were vaccinated. We found 6 complementation groups of neutralizing antibodies. 58% targeted epitopes outside the NTD supersite, 58% neutralized either Gamma or Omicron, and 14% were broad neutralizers that also neutralized Omicron. Structural characterization revealed that broadly active antibodies targeted three epitopes outside the NTD supersite including a class that recognized both the NTD and SD2 domain. Rapid recruitment of memory B cells producing these antibodies into the plasma cell compartment upon re-infection likely contributes to the relatively benign course of subsequent infections with SARS-CoV-2 variants, including Omicron.


Subject(s)
COVID-19 , Spike Glycoprotein, Coronavirus , Antibodies, Monoclonal , Antibodies, Neutralizing , Antibodies, Viral , Epitopes , Humans , Memory B Cells , SARS-CoV-2
8.
EuropePMC;
Preprint in English | EuropePMC | ID: ppcovidwho-327676

ABSTRACT

The omicron variant of SARS-CoV-2 infected very large numbers of SARS-CoV-2 vaccinated and convalescent individuals. The penetrance of this variant in the antigen experienced human population can be explained in part by the relatively low levels of plasma neutralizing activity against Omicron in people who were infected or vaccinated with the original Wuhan-Hu-1 strain. The 3 rd mRNA vaccine dose produces an initial increase in circulating anti-Omicron neutralizing antibodies, but titers remain 10-20-fold lower than against Wuhan-Hu-1 and are, in many cases, insufficient to prevent infection. Despite the reduced protection from infection, individuals that received 3 doses of an mRNA vaccine were highly protected from the more serious consequences of infection. Here we examine the memory B cell repertoire in a longitudinal cohort of individuals receiving 3 mRNA vaccine doses. We find that the 3 rd dose is accompanied by an increase in, and evolution of, anti-receptor binding domain specific memory B cells. The increase is due to expansion of memory B cell clones that were present after the 2 nd vaccine dose as well as the emergence of new clones. The antibodies encoded by these cells showed significantly increased potency and breadth when compared to antibodies obtained after the 2 nd vaccine dose. Notably, the increase in potency was especially evident among newly developing clones of memory cells that differed from the persisting clones in targeting more conserved regions of the RBD. Overall, more than 50% of the analyzed neutralizing antibodies in the memory compartment obtained from individuals receiving a 3 rd mRNA vaccine dose neutralized Omicron. Thus, individuals receiving 3 doses of an mRNA vaccine encoding Wuhan-Hu-1, have a diverse memory B cell repertoire that can respond rapidly and produce antibodies capable of clearing even diversified variants such as Omicron. These data help explain why a 3 rd dose of an mRNA vaccine that was not specifically designed to protect against variants is effective against variant-induced serious disease.

9.
EuropePMC;
Preprint in English | EuropePMC | ID: ppcovidwho-327582

ABSTRACT

Vaccination and infection by viral variants are shaping population immunity to SARS-CoV-21 and breakthrough infections of vaccinated or previously infected individuals have become common as variants evade preexisting immunity. Omicron (B.1.1.529) is highly resistant to plasma neutralizing antibodies elicited by infection with prior variants and the 2-dose mRNA vaccination regimens. However, vaccination after infection or a third mRNA vaccine dose elicit high levels of neutralizing antibodies that can also neutralize omicron to a degree2-4. We compared neutralizing antibody titers in 54 individuals that had received 2 or 3 doses of mRNA vaccines and had experienced breakthrough infection with SARS-CoV-2 variants.

10.
EuropePMC;
Preprint in English | EuropePMC | ID: ppcovidwho-327330

ABSTRACT

Summary SARS-CoV-2 infection or vaccination produces neutralizing antibody responses that contribute to better clinical outcomes. The receptor binding domain (RBD) and the N-terminal domain (NTD) of the spike trimer (S) constitute the two major neutralizing targets for the antibody system. Neutralizing antibodies targeting the RBD bind to several different sites on this domain. In contrast, most neutralizing antibodies to NTD characterized to date bind to a single supersite, however these antibodies were obtained by methods that were not NTD specific. Here we use NTD specific probes to focus on anti-NTD memory B cells in a cohort of pre-omicron infected individuals some of which were also vaccinated. Of 275 NTD binding antibodies tested 103 neutralized at least one of three tested strains: Wuhan-Hu-1, Gamma, or PMS20, a synthetic variant which is extensively mutated in the NTD supersite. Among the 43 neutralizing antibodies that were further characterized, we found 6 complementation groups based on competition binding experiments. 58% targeted epitopes outside the NTD supersite, and 58% neutralized either Gamma or Omicron, but only 14% were broad neutralizers. Three of the broad neutralizers were characterized structurally. C1520 and C1791 recognize epitopes on opposite faces of the NTD with a distinct binding pose relative to previously described antibodies allowing for greater potency and cross-reactivity with 7 different variants including Beta, Delta, Gamma and Omicron. Antibody C1717 represents a previously uncharacterized class of NTD-directed antibodies that recognizes the viral membrane proximal side of the NTD and SD2 domain, leading to cross-neutralization of Beta, Gamma and Omicron. We conclude SARS-CoV-2 infection and/or Wuhan-Hu-1 mRNA vaccination produces a diverse collection of memory B cells that produce anti-NTD antibodies some of which can neutralize variants of concern. Rapid recruitment of these cells into the antibody secreting plasma cell compartment upon re-infection likely contributes to the relatively benign course of subsequent infections with SARS-CoV-2 variants including omicron.

12.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-296969

ABSTRACT

BACKGROUND The Omicron SARS-CoV-2 variant has spread internationally and is responsible for rapidly increasing case numbers. The emergence of divergent variants in the context of a heterogeneous and evolving neutralizing antibody response in host populations might compromise protection afforded by vaccines or prior infection. METHODS We measured neutralizing antibody titers in 169 longitudinally collected plasma samples using pseudotypes bearing the Wuhan-hu-1 or the Omicron variant or a laboratory-designed neutralization-resistant SARS-CoV-2 spike (PMS20). Plasmas were obtained from convalescents who did or did not subsequently receive an mRNA vaccine, or naive individuals who received 3-doses of mRNA or 1-dose Ad26 vaccines. Samples were collected approximately 1, 5-6 and 12 months after initial vaccination or infection. RESULTS Like PMS20, the Omicron spike protein was substantially resistant to neutralization compared to Wuhan-hu-1. In convalescent plasma the median deficit in neutralizing activity against PMS20 or Omicron was 30- to 60-fold. Plasmas from recipients of 2 mRNA vaccine doses were 30- to 180- fold less potent against PMS20 and Omicron than Wuhan-hu-1. Notably, previously infected or two-mRNA dose vaccinated individuals who received additional mRNA vaccine dose(s) had 38 to 154-fold and 35 to 214-fold increases in neutralizing activity against Omicron and PMS20 respectively. CONCLUSIONS Omicron exhibits similar distribution of sequence changes and neutralization resistance as does a laboratory-designed neutralization-resistant spike protein, suggesting natural evolutionary pressure to evade the human antibody response. Currently available mRNA vaccine boosters, that may promote antibody affinity maturation, significantly ameliorate SARS-CoV-2 neutralizing antibody titers.

13.
2021.
Preprint in English | Other preprints | ID: ppcovidwho-296284

ABSTRACT

Over one year after its inception, the coronavirus disease-2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) remains difficult to control despite the availability of several excellent vaccines. Progress in controlling the pandemic is slowed by the emergence of variants that appear to be more transmissible and more resistant to antibodies 1,2 . Here we report on a cohort of 63 COVID-19-convalescent individuals assessed at 1.3, 6.2 and 12 months after infection, 41% of whom also received mRNA vaccines 3,4 . In the absence of vaccination antibody reactivity to the receptor binding domain (RBD) of SARS-CoV-2, neutralizing activity and the number of RBD-specific memory B cells remain relatively stable from 6 to 12 months. Vaccination increases all components of the humoral response, and as expected, results in serum neutralizing activities against variants of concern that are comparable to or greater than neutralizing activity against the original Wuhan Hu-1 achieved by vaccination of naïve individuals 2,5-8 . The mechanism underlying these broad-based responses involves ongoing antibody somatic mutation, memory B cell clonal turnover, and development of monoclonal antibodies that are exceptionally resistant to SARS-CoV-2 RBD mutations, including those found in variants of concern 4,9 . In addition, B cell clones expressing broad and potent antibodies are selectively retained in the repertoire over time and expand dramatically after vaccination. The data suggest that immunity in convalescent individuals will be very long lasting and that convalescent individuals who receive available mRNA vaccines will produce antibodies and memory B cells that should be protective against circulating SARS-CoV-2 variants.

14.
2021.
Preprint in English | Other preprints | ID: ppcovidwho-294471

ABSTRACT

Summary Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection produces B-cell responses that continue to evolve for at least one year. During that time, memory B cells express increasingly broad and potent antibodies that are resistant to mutations found in variants of concern 1 . As a result, vaccination of coronavirus disease 2019 (COVID-19) convalescent individuals with currently available mRNA vaccines produces high levels of plasma neutralizing activity against all variants tested 1, 2 . Here, we examine memory B cell evolution 5 months after vaccination with either Moderna (mRNA-1273) or Pfizer- BioNTech (BNT162b2) mRNA vaccines in a cohort of SARS-CoV-2 naïve individuals. Between prime and boost, memory B cells produce antibodies that evolve increased neutralizing activity, but there is no further increase in potency or breadth thereafter. Instead, memory B cells that emerge 5 months after vaccination of naïve individuals express antibodies that are similar to those that dominate the initial response. While individual memory antibodies selected over time by natural infection have greater potency and breadth than antibodies elicited by vaccination, the overall neutralizing potency of plasma is greater following vaccination. These results suggest that boosting vaccinated individuals with currently available mRNA vaccines will increase plasma neutralizing activity but may not produce antibodies with breadth equivalent to those obtained by vaccinating convalescent individuals.

15.
Nature ; 600(7889): 517-522, 2021 12.
Article in English | MEDLINE | ID: covidwho-1454790

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection produces B cell responses that continue to evolve for at least a year. During that time, memory B cells express increasingly broad and potent antibodies that are resistant to mutations found in variants of concern1. As a result, vaccination of coronavirus disease 2019 (COVID-19) convalescent individuals with currently available mRNA vaccines produces high levels of plasma neutralizing activity against all variants tested1,2. Here we examine memory B cell evolution five months after vaccination with either Moderna (mRNA-1273) or Pfizer-BioNTech (BNT162b2) mRNA vaccine in a cohort of SARS-CoV-2-naive individuals. Between prime and boost, memory B cells produce antibodies that evolve increased neutralizing activity, but there is no further increase in potency or breadth thereafter. Instead, memory B cells that emerge five months after vaccination of naive individuals express antibodies that are similar to those that dominate the initial response. While individual memory antibodies selected over time by natural infection have greater potency and breadth than antibodies elicited by vaccination, the overall neutralizing potency of plasma is greater following vaccination. These results suggest that boosting vaccinated individuals with currently available mRNA vaccines will increase plasma neutralizing activity but may not produce antibodies with equivalent breadth to those obtained by vaccinating convalescent individuals.


Subject(s)
COVID-19 Vaccines/immunology , Evolution, Molecular , Spike Glycoprotein, Coronavirus/immunology , Vaccines, Synthetic/immunology , /immunology , /immunology , Adult , Aged , Antibodies, Monoclonal/immunology , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Antibody Affinity , Cohort Studies , Cross Reactions , Enzyme-Linked Immunosorbent Assay , Epitopes, B-Lymphocyte/immunology , Female , Humans , Male , Middle Aged , Neutralization Tests , Protein Domains/immunology , Spike Glycoprotein, Coronavirus/chemistry , Young Adult
16.
Nature ; 600(7889): 512-516, 2021 12.
Article in English | MEDLINE | ID: covidwho-1428879

ABSTRACT

The number and variability of the neutralizing epitopes targeted by polyclonal antibodies in individuals who are SARS-CoV-2 convalescent and vaccinated are key determinants of neutralization breadth and the genetic barrier to viral escape1-4. Using HIV-1 pseudotypes and plasma selection experiments with vesicular stomatitis virus/SARS-CoV-2 chimaeras5, here we show that multiple neutralizing epitopes, within and outside the receptor-binding domain, are variably targeted by human polyclonal antibodies. Antibody targets coincide with spike sequences that are enriched for diversity in natural SARS-CoV-2 populations. By combining plasma-selected spike substitutions, we generated synthetic 'polymutant' spike protein pseudotypes that resisted polyclonal antibody neutralization to a similar degree as circulating variants of concern. By aggregating variant of concern-associated and antibody-selected spike substitutions into a single polymutant spike protein, we show that 20 naturally occurring mutations in the SARS-CoV-2 spike protein are sufficient to generate pseudotypes with near-complete resistance to the polyclonal neutralizing antibodies generated by individuals who are convalescent or recipients who received an mRNA vaccine. However, plasma from individuals who had been infected and subsequently received mRNA vaccination neutralized pseudotypes bearing this highly resistant SARS-CoV-2 polymutant spike, or diverse sarbecovirus spike proteins. Thus, optimally elicited human polyclonal antibodies against SARS-CoV-2 should be resilient to substantial future SARS-CoV-2 variation and may confer protection against potential future sarbecovirus pandemics.


Subject(s)
Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Immune Evasion , Immune Sera/immunology , Mutation , SARS-CoV-2/genetics , SARS-CoV-2/immunology , COVID-19/immunology , COVID-19/prevention & control , COVID-19/virology , Convalescence , Cross Reactions , Humans , Neutralization Tests , SARS-CoV-2/isolation & purification , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology
17.
Immunity ; 54(8): 1853-1868.e7, 2021 08 10.
Article in English | MEDLINE | ID: covidwho-1330891

ABSTRACT

Antibodies elicited by infection accumulate somatic mutations in germinal centers that can increase affinity for cognate antigens. We analyzed 6 independent groups of clonally related severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) Spike receptor-binding domain (RBD)-specific antibodies from 5 individuals shortly after infection and later in convalescence to determine the impact of maturation over months. In addition to increased affinity and neutralization potency, antibody evolution changed the mutational pathways for the acquisition of viral resistance and restricted neutralization escape options. For some antibodies, maturation imposed a requirement for multiple substitutions to enable escape. For certain antibodies, affinity maturation enabled the neutralization of circulating SARS-CoV-2 variants of concern and heterologous sarbecoviruses. Antibody-antigen structures revealed that these properties resulted from substitutions that allowed additional variability at the interface with the RBD. These findings suggest that increasing antibody diversity through prolonged or repeated antigen exposure may improve protection against diversifying SARS-CoV-2 populations, and perhaps against other pandemic threat coronaviruses.


Subject(s)
Antibody Affinity/immunology , COVID-19/immunology , COVID-19/virology , Host-Pathogen Interactions/immunology , Mutation , SARS-CoV-2/genetics , SARS-CoV-2/immunology , Antibodies, Neutralizing/chemistry , Antibodies, Neutralizing/immunology , Antibodies, Viral/chemistry , Antibodies, Viral/immunology , Antigens, Viral/chemistry , Antigens, Viral/genetics , Antigens, Viral/immunology , Epitopes/chemistry , Epitopes/immunology , Humans , Models, Molecular , Neutralization Tests , Protein Binding , Protein Conformation , SARS-CoV-2/pathogenicity , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/immunology , Structure-Activity Relationship , Virulence/genetics
18.
Nat Commun ; 12(1): 4196, 2021 07 07.
Article in English | MEDLINE | ID: covidwho-1301167

ABSTRACT

Monoclonal antibodies targeting a variety of epitopes have been isolated from individuals previously infected with SARS-CoV-2, but the relative contributions of these different antibody classes to the polyclonal response remains unclear. Here we use a yeast-display system to map all mutations to the viral spike receptor-binding domain (RBD) that escape binding by representatives of three potently neutralizing classes of anti-RBD antibodies with high-resolution structures. We compare the antibody-escape maps to similar maps for convalescent polyclonal plasmas, including plasmas from individuals from whom some of the antibodies were isolated. While the binding of polyclonal plasma antibodies are affected by mutations across multiple RBD epitopes, the plasma-escape maps most resemble those of a single class of antibodies that target an epitope on the RBD that includes site E484. Therefore, although the human immune system can produce antibodies that target diverse RBD epitopes, in practice the polyclonal response to infection is skewed towards a single class of antibodies targeting an epitope that is already undergoing rapid evolution.


Subject(s)
Antibodies, Viral/immunology , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology , Antibodies, Monoclonal/immunology , Antibodies, Neutralizing/immunology , Binding Sites , COVID-19/immunology , Epitopes , HLA Antigens/immunology , Humans , Immune Evasion/genetics , Models, Molecular , Mutation , Neutralization Tests , Protein Domains , SARS-CoV-2/chemistry , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/chemistry
19.
Nature ; 595(7867): 426-431, 2021 07.
Article in English | MEDLINE | ID: covidwho-1267998

ABSTRACT

More than one year after its inception, the coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains difficult to control despite the availability of several working vaccines. Progress in controlling the pandemic is slowed by the emergence of variants that appear to be more transmissible and more resistant to antibodies1,2. Here we report on a cohort of 63 individuals who have recovered from COVID-19 assessed at 1.3, 6.2 and 12 months after SARS-CoV-2 infection, 41% of whom also received mRNA vaccines3,4. In the absence of vaccination, antibody reactivity to the receptor binding domain (RBD) of SARS-CoV-2, neutralizing activity and the number of RBD-specific memory B cells remain relatively stable between 6 and 12 months after infection. Vaccination increases all components of the humoral response and, as expected, results in serum neutralizing activities against variants of concern similar to or greater than the neutralizing activity against the original Wuhan Hu-1 strain achieved by vaccination of naive individuals2,5-8. The mechanism underlying these broad-based responses involves ongoing antibody somatic mutation, memory B cell clonal turnover and development of monoclonal antibodies that are exceptionally resistant to SARS-CoV-2 RBD mutations, including those found in the variants of concern4,9. In addition, B cell clones expressing broad and potent antibodies are selectively retained in the repertoire over time and expand markedly after vaccination. The data suggest that immunity in convalescent individuals will be very long lasting and that convalescent individuals who receive available mRNA vaccines will produce antibodies and memory B cells that should be protective against circulating SARS-CoV-2 variants.


Subject(s)
Antibodies, Neutralizing/blood , Antibodies, Neutralizing/immunology , Antibodies, Viral/blood , Antibodies, Viral/immunology , COVID-19/blood , COVID-19/immunology , SARS-CoV-2/immunology , Adult , Aged , Antibodies, Monoclonal/immunology , B-Lymphocytes/immunology , Enzyme-Linked Immunosorbent Assay , Epitopes/immunology , Female , Humans , Immunologic Memory/immunology , Male , Middle Aged , SARS-CoV-2/chemistry , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/immunology , Time Factors
20.
Nature ; 591(7851): 639-644, 2021 03.
Article in English | MEDLINE | ID: covidwho-1065898

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has infected 78 million individuals and is responsible for over 1.7 million deaths to date. Infection is associated with the development of variable levels of antibodies with neutralizing activity, which can protect against infection in animal models1,2. Antibody levels decrease with time, but, to our knowledge, the nature and quality of the memory B cells that would be required to produce antibodies upon reinfection has not been examined. Here we report on the humoral memory response in a cohort of 87 individuals assessed at 1.3 and 6.2 months after infection with SARS-CoV-2. We find that titres of IgM and IgG antibodies against the receptor-binding domain (RBD) of the spike protein of SARS-CoV-2 decrease significantly over this time period, with IgA being less affected. Concurrently, neutralizing activity in plasma decreases by fivefold in pseudotype virus assays. By contrast, the number of RBD-specific memory B cells remains unchanged at 6.2 months after infection. Memory B cells display clonal turnover after 6.2 months, and the antibodies that they express have greater somatic hypermutation, resistance to RBD mutations and increased potency, indicative of continued evolution of the humoral response. Immunofluorescence and PCR analyses of intestinal biopsies obtained from asymptomatic individuals at 4 months after the onset of coronavirus disease 2019 (COVID-19) revealed the persistence of SARS-CoV-2 nucleic acids and immunoreactivity in the small bowel of 7 out of 14 individuals. We conclude that the memory B cell response to SARS-CoV-2 evolves between 1.3 and 6.2 months after infection in a manner that is consistent with antigen persistence.


Subject(s)
Antibodies, Viral/immunology , COVID-19/immunology , Immunity, Humoral/immunology , SARS-CoV-2/immunology , Adolescent , Adult , Aged , Antibodies, Monoclonal/blood , Antibodies, Monoclonal/immunology , Antibodies, Neutralizing/blood , Antibodies, Neutralizing/genetics , Antibodies, Neutralizing/immunology , Antibodies, Viral/blood , Antibodies, Viral/genetics , Antigens, Viral/chemistry , Antigens, Viral/genetics , Antigens, Viral/immunology , B-Lymphocytes/cytology , B-Lymphocytes/immunology , Biopsy , COVID-19/blood , Cohort Studies , Fluorescent Antibody Technique , Humans , Immunity, Humoral/genetics , Immunoglobulin A/immunology , Immunoglobulin G/immunology , Immunoglobulin M/immunology , Immunologic Memory/immunology , Intestines/immunology , Middle Aged , Mutation , Somatic Hypermutation, Immunoglobulin , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology , Time Factors , Young Adult
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