Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 15 de 15
Filter
1.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-334439

ABSTRACT

Waning immunity after two SARS-CoV-2 mRNA vaccinations and the emergence of variants precipitated the need for a third dose of vaccine. We evaluated early safety and immunogenicity after a third mRNA vaccination in adults who received the mRNA-1273 primary series in the Phase 1 trial approximately 9 to 10 months earlier. The booster vaccine formulations included 100 mcg of mRNA-1273, 50 mcg of mRNA-1273.351 that encodes Beta variant spike protein, and bivalent vaccine of 25 mcg each of mRNA-1273 and mRNA-1273.351. A third dose of mRNA vaccine appeared safe with acceptable reactogenicity. Vaccination induced rapid increases in binding and neutralizing antibody titers to D614G, Beta, and Delta variants that were similar or greater than peak responses after the second dose. Spike-specific CD4+ and CD8+ T cells increased to similar levels as after the second dose. A third mRNA vaccination was well tolerated and generated robust humoral and T cell responses. ClinicalTrials.gov numbers NCT04283461 (mRNA-1273 Phase 1) and NCT04785144 (mRNA-1273.351 Phase 1)

2.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-334405

ABSTRACT

Waning immunity after two SARS-CoV-2 mRNA vaccinations and the emergence of variants precipitated the need for booster doses. We evaluated safety and serological and cellular immunogenicity through 6 months after a third mRNA vaccination in adults who received the mRNA-1273 primary series in the Phase 1 trial approximately 9 to 10 months earlier. The booster vaccine formulations included 100 mcg of mRNA-1273, 50 mcg of mRNA-1273.351 that encodes Beta variant spike protein, and bivalent vaccine of 25 mcg each of mRNA-1273 and mRNA-1273.351. A third dose of mRNA vaccine appeared safe with acceptable reactogenicity. Vaccination induced rapid increases in binding and neutralizing antibody titers to D614G, Beta, Delta and Omicron variants that persisted through 6 months post-boost, particularly after administration of Beta-containing vaccines. Spike-specific CD4 + and CD8 + T cells increased to levels similar to those following the second dose. Boost vaccination induced broad and durable humoral and T cell responses. ClinicalTrials.gov numbers NCT04283461 (mRNA-1273 Phase 1) and NCT04785144 (mRNA-1273.351 Phase 1)

3.
Vaccine ; 39(51): 7394-7400, 2021 12 17.
Article in English | MEDLINE | ID: covidwho-1655207

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of a global pandemic. Safe and effective COVID-19 vaccines are now available, including mRNA-1273, which has shown 94% efficacy in prevention of symptomatic COVID-19 disease. However, the emergence of SARS-CoV-2 variants has led to concerns of viral escape from vaccine-induced immunity. Several variants have shown decreased susceptibility to neutralization by vaccine-induced immunity, most notably B.1.351 (Beta), although the overall impact on vaccine efficacy remains to be determined. Here, we present the initial evaluation in mice of 2 updated mRNA vaccines designed to target SARS-CoV-2 variants: (1) monovalent mRNA-1273.351 encodes for the spike protein found in B.1.351 and (2) mRNA-1273.211 comprising a 1:1 mix of mRNA-1273 and mRNA-1273.351. Both vaccines were evaluated as a 2-dose primary series in mice; mRNA-1273.351 was also evaluated as a booster dose in animals previously vaccinated with mRNA-1273. The results demonstrated that a primary vaccination series of mRNA-1273.351 was effective at increasing neutralizing antibody titers against B.1.351, while mRNA-1273.211 was effective at providing broad cross-variant neutralization. A third (booster) dose of mRNA-1273.351 significantly increased both wild-type and B.1.351-specific neutralization titers. Both mRNA-1273.351 and mRNA-1273.211 are being evaluated in pre-clinical challenge and clinical studies.


Subject(s)
COVID-19 Vaccines , COVID-19 , Animals , Antibodies, Viral , Humans , Mice , SARS-CoV-2 , Vaccination , Vaccines, Synthetic
4.
J Virol ; 95(23): e0131321, 2021 11 09.
Article in English | MEDLINE | ID: covidwho-1434895

ABSTRACT

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants has led to growing concerns over increased transmissibility and the ability of some variants to partially escape immunity. Sera from participants immunized on a prime-boost schedule with the mRNA-1273 COVID-19 vaccine were tested for neutralizing activity against several SARS-CoV-2 variants, including variants of concern (VOCs) and variants of interest (VOIs), compared to neutralization of the wild-type SARS-CoV-2 virus (designated D614G). Results showed minimal, statistically nonsignificant effects on neutralization titers against the B.1.1.7 (Alpha) variant (1.2-fold reduction compared with D614G); other VOCs, such as B.1.351 (Beta, including B.1.351-v1, B.1.351-v2, and B.1.351-v3), P.1 (Gamma), and B.1.617.2 (Delta), showed significantly decreased neutralization titers ranging from 2.1-fold to 8.4-fold reductions compared with D614G, although all remained susceptible to mRNA-1273-elicited serum neutralization. IMPORTANCE In light of multiple variants of SARS-CoV-2 that have been documented globally during the COVID-19 pandemic, it remains important to continually assess the ability of currently available vaccines to confer protection against newly emerging variants. Data presented herein indicate that immunization with the mRNA-1273 COVID-19 vaccine produces neutralizing antibodies against key emerging variants tested, including variants of concern and variants of interest. While the serum neutralization elicited by mRNA-1273 against most variants tested was reduced compared with that against the wild-type virus, the level of neutralization is still expected to be protective. Such data are crucial to inform ongoing and future vaccination strategies to combat COVID-19.


Subject(s)
Antibodies, Neutralizing/immunology , COVID-19 Vaccines/immunology , COVID-19/immunology , COVID-19/prevention & control , Pandemics/prevention & control , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Adult , Antibodies, Viral/immunology , Female , Humans , Male , Mutation , Neutralization Tests , Vaccination
5.
Science ; 373(6561):1372-1377, 2021.
Article in English | Academic Search Complete | ID: covidwho-1426840

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mutations may diminish vaccine-induced protective immune responses, particularly as antibody titers wane over time. Here, we assess the effect of SARS-CoV-2 variants B.1.1.7 (Alpha), B.1.351 (Beta), P.1 (Gamma), B.1.429 (Epsilon), B.1.526 (Iota), and B.1.617.2 (Delta) on binding, neutralizing, and angiotensin-converting enzyme 2 (ACE2)Ð competing antibodies elicited by the messenger RNA (mRNA) vaccine mRNA-1273 over 7 months. Cross-reactive neutralizing responses were rare after a single dose. At the peak of response to the second vaccine dose, all individuals had responses to all variants. Binding and functional antibodies against variants persisted in most subjects, albeit at low levels, for 6 months after the primary series of the mRNA-1273 vaccine. Across all assays, B.1.351 had the lowest antibody recognition. These data complement ongoing studies to inform the potential need for additional boost vaccinations. [ABSTRACT FROM AUTHOR] Copyright of Science is the property of American Association for the Advancement of Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

6.
Nat Med ; 27(11): 2025-2031, 2021 11.
Article in English | MEDLINE | ID: covidwho-1412033

ABSTRACT

The emergence of SARS-CoV-2 variants of concern (VOCs) and variants of interest (VOIs) with decreased susceptibility to neutralization has generated interest in assessments of booster doses and variant-specific vaccines. Clinical trial participants who received a two-dose primary series of the COVID-19 vaccine mRNA-1273 approximately 6 months earlier entered an open-label phase 2a study ( NCT04405076 ) to evaluate the primary objectives of safety and immunogenicity of a single booster dose of mRNA-1273 or variant-modified mRNAs, including multivalent mRNA-1273.211. As the trial is currently ongoing, this exploratory interim analysis includes preliminary descriptive results only of four booster groups (n = 20 per group). Immediately before the booster dose, neutralizing antibodies against wild-type D614G virus had waned (P < 0.0001) relative to peak titers against wild-type D614G measured 1 month after the primary series, and neutralization titers against B.1.351 (Beta), P.1 (Gamma) and B.1.617.2 (Delta) VOCs were either low or undetectable. Both the mRNA-1273 booster and variant-modified boosters were safe and well-tolerated. All boosters, including mRNA-1273, numerically increased neutralization titers against the wild-type D614G virus compared to peak titers against wild-type D614G measured 1 month after the primary series; significant increases were observed for mRNA-1273 and mRNA-1273.211 (P < 0.0001). In addition, all boosters increased neutralization titers against key VOCs and VOIs, including B.1.351, P.1. and B.1.617.2, that were statistically equivalent to peak titers measured after the primary vaccine series against wild-type D614G virus, with superior titers against some VOIs. This trial is ongoing.


Subject(s)
COVID-19 Vaccines/immunology , COVID-19/prevention & control , Immunization, Secondary , Immunogenicity, Vaccine , SARS-CoV-2/immunology , Adult , Aged , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , COVID-19/immunology , COVID-19 Vaccines/adverse effects , Female , Healthy Volunteers , Humans , Immunization, Secondary/adverse effects , Male , Middle Aged , Preliminary Data , RNA, Messenger/adverse effects , RNA, Messenger/genetics , RNA, Messenger/immunology , SARS-CoV-2/genetics , Treatment Outcome , United States , Vaccination/adverse effects
7.
Science ; 373(6561): 1372-1377, 2021 Sep 17.
Article in English | MEDLINE | ID: covidwho-1356908

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mutations may diminish vaccine-induced protective immune responses, particularly as antibody titers wane over time. Here, we assess the effect of SARS-CoV-2 variants B.1.1.7 (Alpha), B.1.351 (Beta), P.1 (Gamma), B.1.429 (Epsilon), B.1.526 (Iota), and B.1.617.2 (Delta) on binding, neutralizing, and angiotensin-converting enzyme 2 (ACE2)­competing antibodies elicited by the messenger RNA (mRNA) vaccine mRNA-1273 over 7 months. Cross-reactive neutralizing responses were rare after a single dose. At the peak of response to the second vaccine dose, all individuals had responses to all variants. Binding and functional antibodies against variants persisted in most subjects, albeit at low levels, for 6 months after the primary series of the mRNA-1273 vaccine. Across all assays, B.1.351 had the lowest antibody recognition. These data complement ongoing studies to inform the potential need for additional boost vaccinations.


Subject(s)
Antibodies, Neutralizing/blood , Antibodies, Viral/blood , COVID-19 Vaccines/immunology , SARS-CoV-2/immunology , Adolescent , Adult , Aged , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19/prevention & control , COVID-19 Vaccines/administration & dosage , Cross Reactions , Humans , Immune Evasion , Immunization, Secondary , Immunogenicity, Vaccine , Middle Aged , Time Factors , Young Adult
10.
Vaccine ; 39(20): 2791-2799, 2021 05 12.
Article in English | MEDLINE | ID: covidwho-1071989

ABSTRACT

BACKGROUND: Vaccines are urgently needed to prevent the global spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We assessed the safety and immunogenicity of vaccine candidate mRNA-1273, encoding the prefusion-stabilized spike protein of SARS-CoV-2. METHODS: This phase 2, randomized, observer-blind, placebo-controlled trial was conducted at 8 sites in the USA, in healthy adults aged ≥18 years with no known history or risk of SARS-CoV-2 infection, and had not previously received an investigational CoV vaccine or treatment. Participants were stratified into two age cohorts (≥18-<55 and ≥55) and were randomly assigned (1:1:1) to either 50 or 100 µg of mRNA-1273, or placebo administered as two intramuscular injections 28 days apart. The primary outcomes were safety, reactogenicity, and immunogenicity assessed by anti-SARS-CoV-2-spike binding antibody level (bAb). Secondary outcome was immunogenicity assessed by SARS-CoV-2 neutralizing antibody (nAb) response. RESULTS: Between 29 May and 8 July 2020, 600 participants were randomized, 300 per age cohort. The most common solicited adverse reactions were pain at injection site, headache, and fatigue following each vaccination in both age cohorts. One serious adverse event deemed unrelated by the site investigator occurred 33 days post-vaccination one. mRNA-1273 induced bAb and nAb by 28 days post-vaccination one that were higher at the 100 µg dose relative to the 50 µg dose; this difference was less apparent post-vaccination two. Binding antibodies and nAb increased substantially by 14 days following the second vaccination (day 43) to levels exceeding those of convalescent sera and remained elevated through day 57. CONCLUSIONS: Vaccination with mRNA-1273 resulted in significant immune responses to SARS-CoV-2 in participants 18 years and older, with an acceptable safety profile, confirming the safety and immunogenicity of 50 and 100 µg mRNA-1273 given as a 2 dose-regimen. ClinicalTrials.gov; NCT04405076.


Subject(s)
COVID-19 , Vaccines , Adolescent , Adult , Antibodies, Viral , COVID-19/therapy , COVID-19 Vaccines , Double-Blind Method , Humans , Immunization, Passive , Immunogenicity, Vaccine , RNA, Messenger , SARS-CoV-2
11.
N Engl J Med ; 384(5): 403-416, 2021 02 04.
Article in English | MEDLINE | ID: covidwho-998039

ABSTRACT

BACKGROUND: Vaccines are needed to prevent coronavirus disease 2019 (Covid-19) and to protect persons who are at high risk for complications. The mRNA-1273 vaccine is a lipid nanoparticle-encapsulated mRNA-based vaccine that encodes the prefusion stabilized full-length spike protein of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes Covid-19. METHODS: This phase 3 randomized, observer-blinded, placebo-controlled trial was conducted at 99 centers across the United States. Persons at high risk for SARS-CoV-2 infection or its complications were randomly assigned in a 1:1 ratio to receive two intramuscular injections of mRNA-1273 (100 µg) or placebo 28 days apart. The primary end point was prevention of Covid-19 illness with onset at least 14 days after the second injection in participants who had not previously been infected with SARS-CoV-2. RESULTS: The trial enrolled 30,420 volunteers who were randomly assigned in a 1:1 ratio to receive either vaccine or placebo (15,210 participants in each group). More than 96% of participants received both injections, and 2.2% had evidence (serologic, virologic, or both) of SARS-CoV-2 infection at baseline. Symptomatic Covid-19 illness was confirmed in 185 participants in the placebo group (56.5 per 1000 person-years; 95% confidence interval [CI], 48.7 to 65.3) and in 11 participants in the mRNA-1273 group (3.3 per 1000 person-years; 95% CI, 1.7 to 6.0); vaccine efficacy was 94.1% (95% CI, 89.3 to 96.8%; P<0.001). Efficacy was similar across key secondary analyses, including assessment 14 days after the first dose, analyses that included participants who had evidence of SARS-CoV-2 infection at baseline, and analyses in participants 65 years of age or older. Severe Covid-19 occurred in 30 participants, with one fatality; all 30 were in the placebo group. Moderate, transient reactogenicity after vaccination occurred more frequently in the mRNA-1273 group. Serious adverse events were rare, and the incidence was similar in the two groups. CONCLUSIONS: The mRNA-1273 vaccine showed 94.1% efficacy at preventing Covid-19 illness, including severe disease. Aside from transient local and systemic reactions, no safety concerns were identified. (Funded by the Biomedical Advanced Research and Development Authority and the National Institute of Allergy and Infectious Diseases; COVE ClinicalTrials.gov number, NCT04470427.).


Subject(s)
COVID-19 Vaccines , COVID-19/prevention & control , SARS-CoV-2 , Adolescent , Adult , Aged , COVID-19/diagnosis , COVID-19/immunology , COVID-19 Vaccines/adverse effects , COVID-19 Vaccines/immunology , Female , Humans , Incidence , Male , Middle Aged , Patient Acuity , Single-Blind Method , Spike Glycoprotein, Coronavirus , Treatment Outcome , Young Adult
12.
N Engl J Med ; 383(20): 1920-1931, 2020 11 12.
Article in English | MEDLINE | ID: covidwho-971502

ABSTRACT

BACKGROUND: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in late 2019 and spread globally, prompting an international effort to accelerate development of a vaccine. The candidate vaccine mRNA-1273 encodes the stabilized prefusion SARS-CoV-2 spike protein. METHODS: We conducted a phase 1, dose-escalation, open-label trial including 45 healthy adults, 18 to 55 years of age, who received two vaccinations, 28 days apart, with mRNA-1273 in a dose of 25 µg, 100 µg, or 250 µg. There were 15 participants in each dose group. RESULTS: After the first vaccination, antibody responses were higher with higher dose (day 29 enzyme-linked immunosorbent assay anti-S-2P antibody geometric mean titer [GMT], 40,227 in the 25-µg group, 109,209 in the 100-µg group, and 213,526 in the 250-µg group). After the second vaccination, the titers increased (day 57 GMT, 299,751, 782,719, and 1,192,154, respectively). After the second vaccination, serum-neutralizing activity was detected by two methods in all participants evaluated, with values generally similar to those in the upper half of the distribution of a panel of control convalescent serum specimens. Solicited adverse events that occurred in more than half the participants included fatigue, chills, headache, myalgia, and pain at the injection site. Systemic adverse events were more common after the second vaccination, particularly with the highest dose, and three participants (21%) in the 250-µg dose group reported one or more severe adverse events. CONCLUSIONS: The mRNA-1273 vaccine induced anti-SARS-CoV-2 immune responses in all participants, and no trial-limiting safety concerns were identified. These findings support further development of this vaccine. (Funded by the National Institute of Allergy and Infectious Diseases and others; mRNA-1273 ClinicalTrials.gov number, NCT04283461).


Subject(s)
Coronavirus Infections/prevention & control , Pandemics/prevention & control , Pneumonia, Viral/prevention & control , RNA, Messenger/immunology , Spike Glycoprotein, Coronavirus/immunology , Viral Vaccines/therapeutic use , Adult , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , Antibody Formation , Betacoronavirus , COVID-19 , COVID-19 Vaccines , Female , Humans , Immunization, Secondary , Male , SARS-CoV-2 , T-Lymphocytes/immunology , Viral Vaccines/adverse effects , Young Adult
14.
N Engl J Med ; 383(25): 2427-2438, 2020 12 17.
Article in English | MEDLINE | ID: covidwho-811499

ABSTRACT

BACKGROUND: Testing of vaccine candidates to prevent infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in an older population is important, since increased incidences of illness and death from coronavirus disease 2019 (Covid-19) have been associated with an older age. METHODS: We conducted a phase 1, dose-escalation, open-label trial of a messenger RNA vaccine, mRNA-1273, which encodes the stabilized prefusion SARS-CoV-2 spike protein (S-2P) in healthy adults. The trial was expanded to include 40 older adults, who were stratified according to age (56 to 70 years or ≥71 years). All the participants were assigned sequentially to receive two doses of either 25 µg or 100 µg of vaccine administered 28 days apart. RESULTS: Solicited adverse events were predominantly mild or moderate in severity and most frequently included fatigue, chills, headache, myalgia, and pain at the injection site. Such adverse events were dose-dependent and were more common after the second immunization. Binding-antibody responses increased rapidly after the first immunization. By day 57, among the participants who received the 25-µg dose, the anti-S-2P geometric mean titer (GMT) was 323,945 among those between the ages of 56 and 70 years and 1,128,391 among those who were 71 years of age or older; among the participants who received the 100-µg dose, the GMT in the two age subgroups was 1,183,066 and 3,638,522, respectively. After the second immunization, serum neutralizing activity was detected in all the participants by multiple methods. Binding- and neutralizing-antibody responses appeared to be similar to those previously reported among vaccine recipients between the ages of 18 and 55 years and were above the median of a panel of controls who had donated convalescent serum. The vaccine elicited a strong CD4 cytokine response involving type 1 helper T cells. CONCLUSIONS: In this small study involving older adults, adverse events associated with the mRNA-1273 vaccine were mainly mild or moderate. The 100-µg dose induced higher binding- and neutralizing-antibody titers than the 25-µg dose, which supports the use of the 100-µg dose in a phase 3 vaccine trial. (Funded by the National Institute of Allergy and Infectious Diseases and others; mRNA-1273 Study ClinicalTrials.gov number, NCT04283461.).


Subject(s)
COVID-19 Vaccines/adverse effects , COVID-19 Vaccines/immunology , COVID-19/prevention & control , SARS-CoV-2/immunology , Aged , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , COVID-19/immunology , COVID-19 Vaccines/administration & dosage , Dose-Response Relationship, Drug , Female , Humans , Male , Middle Aged , Neutralization Tests , Spike Glycoprotein, Coronavirus , T-Lymphocytes/physiology
15.
Nature ; 586(7830): 567-571, 2020 10.
Article in English | MEDLINE | ID: covidwho-703377

ABSTRACT

A vaccine for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is needed to control the coronavirus disease 2019 (COVID-19) global pandemic. Structural studies have led to the development of mutations that stabilize Betacoronavirus spike proteins in the prefusion state, improving their expression and increasing immunogenicity1. This principle has been applied to design mRNA-1273, an mRNA vaccine that encodes a SARS-CoV-2 spike protein that is stabilized in the prefusion conformation. Here we show that mRNA-1273 induces potent neutralizing antibody responses to both wild-type (D614) and D614G mutant2 SARS-CoV-2 as well as CD8+ T cell responses, and protects against SARS-CoV-2 infection in the lungs and noses of mice without evidence of immunopathology. mRNA-1273 is currently in a phase III trial to evaluate its efficacy.


Subject(s)
Betacoronavirus/immunology , Coronavirus Infections/immunology , Coronavirus Infections/prevention & control , Pandemics/prevention & control , Pneumonia, Viral/immunology , Pneumonia, Viral/prevention & control , Viral Vaccines/immunology , Animals , Antibodies, Neutralizing/immunology , Betacoronavirus/genetics , CD8-Positive T-Lymphocytes/immunology , COVID-19 , COVID-19 Vaccines , Clinical Trials, Phase III as Topic , Coronavirus Infections/genetics , Coronavirus Infections/virology , Female , Lung/immunology , Lung/virology , Mice , Mutation , Nose/immunology , Nose/virology , Pneumonia, Viral/virology , RNA, Messenger/genetics , RNA, Viral/genetics , SARS-CoV-2 , Th1 Cells/immunology , Toll-Like Receptor 4/agonists , Toll-Like Receptor 4/immunology , Viral Vaccines/chemistry , Viral Vaccines/genetics
SELECTION OF CITATIONS
SEARCH DETAIL