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1.
Microbiol Spectr ; 11(3): e0436322, 2023 Jun 15.
Article in English | MEDLINE | ID: covidwho-2316073

ABSTRACT

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants has raised concerns about reduced vaccine effectiveness and the increased risk of infection, and while repeated homologous booster shots are recommended for elderly and immunocompromised individuals, they cannot completely protect against breakthrough infections. In our previous study, we assessed the immunogenicity of an adenovirus-based vaccine expressing SARS-CoV-2 S1 (Ad5.S1) in mice, which induced robust humoral and cellular immune responses (E. Kim, F. J. Weisel, S. C. Balmert, M. S. Khan, et al., Eur J Immunol 51:1774-1784, 2021, https://doi.org/10.1002/eji.202149167). In this follow-up study, we found that the mice had high titers of anti-S1 antibodies 1 year after vaccination, and one booster dose of the nonadjuvanted rS1Beta (recombinant S1 protein of SARS-CoV-2 Beta [B.1.351]) subunit vaccine was effective at stimulating strong long-lived S1-specific immune responses and inducing significantly high neutralizing antibodies against Wuhan, Beta, and Delta strains, with 3.6- to 19.5-fold increases. Importantly, the booster dose also elicited cross-reactive antibodies, resulting in angiotensin-converting enzyme 2 (ACE2) binding inhibition against spikes of SARS-CoV-2, including Omicron variants, persisting for >28 weeks after booster vaccination. Interestingly, the levels of neutralizing antibodies were correlated not only with the level of S1 binding IgG but also with ACE2 inhibition. Our findings suggest that the rS1Beta subunit vaccine candidate as a booster has the potential to offer cross-neutralization against broad variants and has important implications for the vaccine control of newly emerging breakthrough SARS-CoV-2 variants in elderly individuals primed with adenovirus-based vaccines like AZD1222 and Ad26.COV2.S. IMPORTANCE Vaccines have significantly reduced the incidences of severe coronavirus disease 2019 (COVID-19) cases and deaths. However, the emergence of SARS-CoV-2 variants has raised concerns about their increased transmissibility and ability to evade neutralizing antibodies, especially among elderly individuals who are at higher risks of mortality and reductions of vaccine effectiveness. To address this, a heterologous booster vaccination strategy has been considered as a solution to protect the elderly population against breakthrough infections caused by emerging variants. This study evaluated the booster effect of an S1 subunit vaccine in aged mice that had been previously primed with adenoviral vaccines, providing valuable preclinical evidence for elderly people vaccinated with the currently approved COVID-19 vaccines. This study confirms the potential for using the S1 subunit vaccine as a booster to enhance cross-neutralizing antibodies against emerging variants of concern.


Subject(s)
COVID-19 , Immunity, Humoral , Aged , Humans , Animals , Mice , SARS-CoV-2/genetics , Angiotensin-Converting Enzyme 2 , Ad26COVS1 , COVID-19 Vaccines , ChAdOx1 nCoV-19 , Follow-Up Studies , COVID-19/prevention & control , Vaccination , Antibodies, Neutralizing , Breakthrough Infections , Antibodies, Viral
2.
Int J Mol Sci ; 24(7)2023 Apr 04.
Article in English | MEDLINE | ID: covidwho-2298481

ABSTRACT

The role and durability of the immunogenicity of the BNT162b2 mRNA vaccine against severe acute respiratory virus 2 (SARS-CoV-2), in cancer patients one year after receiving the third dose have to be elucidated. We have prospectively evaluated the long-term immunogenicity of the third dose of the SARS-CoV-2 BNT162b2 mRNA vaccine in 55 patients undergoing active treatment. Neutralizing antibody (NT Ab) titers against Omicron variants and total anti-trimeric S IgG levels were measured one year after the third dose. Heparinized whole-blood samples were used for the assessment of the SARS-CoV-2 interferon-γ release assay (IGRA). Thirty-seven patients (67.3%) showed positive total anti-trimeric S IgG one year after the third dose. Looking at the T-cell response against the spike protein, the frequency of responder patients did not decrease significantly between six and twelve months after the third dose. Finally, less than 20% of cancer patients showed an undetectable NT Ab titer against BA.1 and BA.5 variants of concern (VOCs). Underlying therapies seem to not affect the magnitude or frequency of the immune response. Our work underlines the persistence of humoral and cellular immune responses against BNT162b2 in a cohort of cancer patients one year after receiving the third dose, regardless of the type of underlying therapy.


Subject(s)
COVID-19 , Neoplasms , Virus Diseases , Humans , BNT162 Vaccine , COVID-19 Vaccines , Follow-Up Studies , SARS-CoV-2 , COVID-19/prevention & control , Neoplasms/therapy , Antibodies, Neutralizing , Immunity , Immunoglobulin G , Antibodies, Viral
3.
iScience ; 26(4): 106562, 2023 Apr 21.
Article in English | MEDLINE | ID: covidwho-2295366

ABSTRACT

This study reports the isolation and characterization of a human monoclonal antibody (mAb) called 19n01. This mAb was isolated by using single-cell RNAseq of B cells from donors infected with the ancestral strain. This mAb possesses a potent and broad capacity to bind and neutralize all previously circulating variants of concern (VOCs), including Omicron sublineages BA.1, BA.2, and BA.4/5. The pseudovirus neutralization assay revealed robust neutralization capacity against the G614 strain, BA.1, BA.2, and BA.4/5, with inhibitory concentration (IC50) values ranging from 0.0035 to 0.0164 µg/mL. The microneutralization assay using the G614 strain and VOCs demonstrated IC50 values of 0.013-0.267 µg/mL. Biophysical and structural analysis showed that 19n01 cross-competes with ACE2 binding to the receptor-binding domain (RBD) and the kinetic parameters confirmed the high affinity against the Omicron sublineages (KD of 61 and 30 nM for BA.2 and BA.4/5, respectively). These results suggest that the 19n01 is a remarkably potent and broadly reactive mAb.

4.
iScience ; 2023.
Article in English | EuropePMC | ID: covidwho-2260145

ABSTRACT

This study reports the isolation and characterization of a human monoclonal antibody (mAb) called 19n01. This mAb was isolated by using single-cell RNAseq of B cells from donors infected with the ancestral strain. This mAb possesses a potent and broad capacity to bind and neutralize all previously circulating variants of concern (VOCs), including Omicron sublineages BA.1, BA.2, and BA.4/5. The pseudovirus neutralization assay revealed robust neutralization capacity against the G614 strain, BA.1, BA.2, and BA.4/5, with IC50 values ranging from 0.0035 to 0.0164 μg/mL. The microneutralization assay using the G614 strain and VOCs demonstrated IC50 values of 0.013 to 0.267 μg/mL. Biophysical and structural analysis showed that 19n01 cross-competes with ACE2 binding to the RBD and the kinetic parameters confirmed the high affinity against the Omicron sublineages (KD of 61 and 30 nM for BA.2 and BA.4/5, respectively). These results suggest that the 19n01 is a remarkably potent and broadly reactive mAb. Graphical

5.
J Infect Public Health ; 16(5): 736-740, 2023 May.
Article in English | MEDLINE | ID: covidwho-2279561

ABSTRACT

INTRODUCTION: Although the potential role of inanimate surfaces in SARS-CoV-2 transmission has yet to be adequately assessed, it is still routine practice to apply deep and expensive environmental disinfection protocols. The aim of this study was to verify the presence of viable virus on different surfaces exposed to droplets released by coughing in SARS-CoV-2 RNA positive patients. METHODS: Patients admitted to hospital with a positive SARS-CoV-2 real-time (RT)-PCR swab were asked to cough on steel, cardboard, plastic and their hands. Surfaces were tested at baseline (T0) and at different timepoints thereafter using swabs dipped in medium, and quickly seeded on VERO E6 cells that were checked every other day for cytopathic effect (CPE). Laboratory-propagated SARS-CoV-2 strains were examined at the same time points and on identical materials. RESULTS: Ten RNA-positive patients were enrolled into the study. The median cycle threshold value was 20.7 (range 13-28.3). Nasopharyngeal swabs from 3 of the patients yielded viable virus 2-10 days post-inoculation. However, in none of the patients was it possible to isolate viable SARS-CoV-2 from sputum under identical experimental conditions. A CPE was instead already visible using laboratory-propagated SARS-CoV-2 strains at 20', 60', 180' while an effect at 24 h required a 6-day incubation. CONCLUSION: The evidence emerging from this real-life study suggests that droplets delivered by SARS-CoV-2 infected patients on common inanimate surfaces did not contain viable virus. In contrast, and in line with several laboratory-based experiments, in vitro adapted viruses could survive and grow on the same fomites.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , SARS-CoV-2/genetics , RNA, Viral/genetics , Fomites , Hospitals
6.
COVID ; 2(11):1564-1574, 2022.
Article in English | MDPI | ID: covidwho-2090031

ABSTRACT

Background and Objectives: New SARS-CoV-2 variants may impact the effectiveness of previously stored convalescent plasma (CCP). We defined levels of anti-delta and anti-omicron SARS-CoV-2 neutralizing antibodies (Nt-Abs) and investigated possible differences of past CCP Nt-Abs responses related to donor location in North and South Italy. Methods: Serum from 153 donors recovered from SARS-COV-2 infection (98 from northern and 55 from southern Italy) were analyzed for Nt-Abs characterization using our in house microneutralization assay. Results were compared to anti-Spike IgG measured by chemiluminescent assay (CLIA) to define a possible agreement with a more affordable test. Results: delta Nt-Abs titer in comparison to the reference strain (PV10734 D614G) showed a reduction of 82% in northern and 77% in southern Italy groups. Omicron Nt-Abs titer showed a reduction of 97%. CCP corresponding to Nt-Abs titer > 1:80 showed a median of 1365 BAU/mL for delta strain and 653 BAU/mL for reference strain. We found no statistical differences between Nt-Abs responses in North and South CCP donors. Conclusions: Not all past CCP could be used to treat patients with SARS-CoV-2 delta and omicron infections due to the lack of specific Nt-Abs. For the moment, the neutralization test remains the gold standard to select potential CCP donors. Interestingly, our study did not find NT-Abs differences between plasma collected from donors living in different areas of Italy.

7.
Vaccines (Basel) ; 10(11)2022 Oct 27.
Article in English | MEDLINE | ID: covidwho-2090387

ABSTRACT

We reported the long-term kinetics of immune response after vaccination and evaluated the immunogenicity after a third dose of mRNA vaccine in 86 healthcare workers. Humoral response was analyzed by measuring anti-spike IgG and SARS-CoV-2 NTAbs titer; cell-mediated response was measured as frequency of IFN-γ producing T-cells and cell proliferation. Memory B cells secreting SARS-CoV-2 RBD-IgG were measured by B-spot assay. At three weeks after the third dose (T4), the frequency of subjects showing NT-Abs titer at the upper detection limit (≥640) was significantly higher than that observed at three weeks after the second dose (26/77; 33.7% vs. 9/77; 11.6%; p = 0.0018). Additionally, at T4, all the subjects reached positive levels of T-cell mediated response (median 110 SFU/106 PBMC, IQR 73-231). While the number of IFNγ-producing T-cells decreased between second and third dose administration, the T-cell proliferative response did not decrease but was sustained during the follow-up. Among T-cell subsets, a higher proliferative response was observed in CD4+ than in CD8+ population. Moreover, even if a decline in antibody response was observed between the second and third dose, a sustained persistence of memory B cells was observed. Subsequently, the third dose did not affect the frequency of memory B cells, while it restored or increased the peak antibody levels detected after the second dose.

8.
Viruses ; 14(7)2022 06 30.
Article in English | MEDLINE | ID: covidwho-1917789

ABSTRACT

COVID-19 convalescent plasma (CCP) has been the only specific anti-viral therapy against SARS-CoV-2 available for more than one year. Following the negative results from most randomized controlled trials on its efficacy in COVID-19 hospitalized patients and the availability of anti-spike monoclonal antibodies (mAbs), the use of CCP has subsequently rapidly faded. However, the continuous appearance of new variants of concern (VOCs), most of which escape mAbs and vaccine-elicited neutralizing antibodies (nAbs), has renewed the interest towards CCP, at least in seronegative immunocompetent patients, and in immunocompromised patients not able to mount a protective immune response. We report here the experience of a single Italian hospital in collecting and transfusing CCP in immunocompromised patients hospitalized for severe COVID-19 between October 2021 and March 2022. During this 6-month period, we collected CCP from 32 vaccinated and convalescent regular blood donors, and infused high nAb-titer CCP units (titered against the specific VOC affecting the recipient) to 21 hospitalized patients with severe COVID-19, all of them seronegative at the time of CCP transfusion. Patients' median age was 66 years (IQR 50-74 years) and approximately half of them (47.6%, 10/21) were immunocompromised. Two patients were rescued after previous failure of mAbs. No adverse reactions following CCP transfusion were recorded. A 28-day mortality rate of 14.3 percent (3/21) was reported, with age, advanced disease stage and late CCP transfusion associated with a worse outcome. This real-life experience also supports the use of CCP in seronegative hospitalized COVID-19 patients during the Delta and Omicron waves.


Subject(s)
COVID-19 , SARS-CoV-2 , Aged , Antibodies, Neutralizing , Antibodies, Viral , COVID-19/therapy , Humans , Immunization, Passive/methods , COVID-19 Serotherapy
9.
Vaccines (Basel) ; 10(5)2022 Apr 29.
Article in English | MEDLINE | ID: covidwho-1820440

ABSTRACT

SARS-CoV-2 still represents a global health burden, causing more than six million deaths worldwide. Moreover, the emergence of new variants has posed new issues in terms of vaccine efficacy and immunogenicity. In this study, we aimed to evaluate the neutralizing antibody response against SARS-CoV-2 variants in different cohorts of vaccinated and unvaccinated subjects. Four-fold diluted sera from SARS-CoV-2 naïve and recovered subjects vaccinated with two or three doses of the BNT162b2 vaccine were challenged against 14 SARS-CoV-2 variants, and the SARS-CoV-2 neutralizing antibody titer was measured. Results were compared with those obtained from unvaccinated COVID-19 recovered patients. Overall, a better SARS-CoV-2 NT Abs response was observed in recovered vaccinated subjects after three doses of the vaccine when compared to unvaccinated patients and vaccinated subjects with only two doses. Additionally, the lowest level of response was observed against the Omicron variant. In conclusion, third doses of BNT162b2 vaccine seems to elicit a sustained response against the large majority of variants.

10.
Transfusion ; 62(6): 1171-1176, 2022 06.
Article in English | MEDLINE | ID: covidwho-1794552

ABSTRACT

BACKGROUND: Novel SARS-CoV-2 variants of concern (VOC) Delta and Omicron are able to escape some monoclonal antibody therapies, making again COVID-19 convalescent plasma (CCP) a potential frontline treatment. STUDY DESIGN/METHODS: In this study, we investigated the kinetics of anti-SARS-CoV-2 neutralizing antibodies (nAbs) against VOCs Delta and Omicron in vaccine breakthrough infected plasma donors. Serum samples from 19 donors were collected at the time of plasma donation and tested for anti-SARS-CoV-2 nAbs (using live authentic VOC viral neutralization test) and IgG (Liaison® SARS-CoV-2 S1/S2 and Liaison® SARS-CoV-2 TrimericS IgG assays, DiaSorin). Measures were correlated with different variables, including the time between last vaccine dose and CCP donation, and time between SARS-COV-2 infection and CCP donation. RESULTS: nAb titers against VOC Delta and Omicron were directly related to the time interval since last vaccine dose to CCP donation, but inversely related to time since COVID19 breakthrough infection. DISCUSSION: SARS-CoV-2 breakthrough infection in vaccinated in donors boosts nAb titers against VOCs Delta and Omicron, but such titers decay shortly after infection. Therefore, CCP must be collected early after vaccine breakthrough infection.


Subject(s)
COVID-19 , Viral Vaccines , Antibodies, Neutralizing , Antibodies, Viral , Blood Donors , COVID-19/prevention & control , COVID-19/therapy , Humans , Immunization, Passive , Immunoglobulin G , Neutralization Tests , SARS-CoV-2 , COVID-19 Serotherapy
12.
Transfus Apher Sci ; 61(4): 103398, 2022 Aug.
Article in English | MEDLINE | ID: covidwho-1683633

ABSTRACT

BACKGROUND: Test the ability of Mirasol Pathogen Reduction Technology (PRT, Terumo BCT, Lakewood Co, USA) treatment with riboflavin and ultraviolet light (R + UV) in reducing SARS-CoV-2 infectivity while maintaining blood product quality. MATERIAL AND METHODS: SARS-CoV-2 strains were isolated and titrated to prepare cell free virus for plasma units infection. The units were then under treatment with Mirasol PRT. The infectious titers were determined before and after treatment with an in house microtitration assay on Vero E6 cells. Thirty-six plasma pool bags underwent PRT treatment. RESULTS: In all the experiments, the measured titer following riboflavin and UV treatment was below the limit of detection of microtitration assay for all the different SARS-CoV-2 strains. Despite the high copies number detected by RT-PCR for each viral strain after treatment, viruses were completely inactivated and not able to infect VERO E6 cells. CONCLUSION: Riboflavin and UV light treatment effectively reduced the virus titers of human plasma to the limit of detection in tissue culture, regardless of the strain. These data suggest that pathogen reduction in blood products highlight the safety of CP therapy procedures for critically ill COVID-19 patients, while maintaining blood product quality.


Subject(s)
COVID-19 Drug Treatment , SARS-CoV-2 , Humans , Riboflavin/pharmacology , Ultraviolet Rays
13.
iScience ; 25(2): 103743, 2022 Feb 18.
Article in English | MEDLINE | ID: covidwho-1611783

ABSTRACT

Information concerning the longevity of immunity to SARS-CoV-2 following natural infection may have considerable implications for durability of immunity induced by vaccines. Here, we monitored the SARS-CoV-2 specific immune response in COVID-19 patients followed up to 15 months after symptoms onset. Following a peak at day 15-28 postinfection, the IgG antibody response and plasma neutralizing titers gradually decreased over time but stabilized after 6 months. Compared to G614, plasma neutralizing titers were more than 8-fold lower against variants Beta, Gamma, and Delta. SARS-CoV-2-specific memory B and T cells persisted in the majority of patients up to 15 months although a significant decrease in specific T cells, but not B cells, was observed between 6 and 15 months. Antiviral specific immunity, especially memory B cells in COVID-19 convalescent patients, is long-lasting, but some variants of concern may at least partially escape the neutralizing activity of plasma antibodies.

14.
Microorganisms ; 9(12)2021 Dec 18.
Article in English | MEDLINE | ID: covidwho-1580570

ABSTRACT

The immunogenicity of severe acute respiratory syndrome 2 virus (SARS-CoV-2) vaccines in immunocompromised patients remains to be further explored. Here, we evaluated the immunogenicity elicited by complete vaccination with BNT162b2 vaccine in solid organ transplant recipients (SOTRs). A cohort of 110 SOTRs from Northern Italy were vaccinated with two doses of BNT162b2 mRNA vaccine and prospectively monitored at baseline and after 42 days. Both SARS-CoV-2 naïve and recovered subjects were included. Humoral response elicited by vaccination, including SARS-CoV-2 neutralizing antibodies (SARS-CoV-2 NT Abs), was evaluated; additionally, ex-vivo ELISpot assay was performed for the quantification of Spike-specific T-cell response. Results were compared with those obtained in a cohort of healthy subjects. In a subset of patients, humoral and T-cell responses against delta variant were also evaluated. Less than 20% of transplanted subjects developed a positive humoral and cell-mediated response after complete vaccination schedule. Overall, median levels of immune response elicited by vaccination were significantly lower with respect to controls in SARS-CoV-2 naïve transplant, but not in SARS-CoV-2 recovered transplanted patients. Additionally, a significant impairment of both humoral and cell-mediated response was observed in mycophenolate-treated patients. Positive delta-SARS-CoV-2 NT Abs levels were detected in almost all the SARS-CoV-2 recovered subjects but not in previously uninfected patients. Our study supports previous observations of a low level of seroconversion after vaccination in transplanted patients.

15.
Viruses ; 13(11)2021 11 11.
Article in English | MEDLINE | ID: covidwho-1512700

ABSTRACT

The development and persistence of SARS-CoV-2-specific immune response in immunocompetent (IC) and immunocompromised patients is crucial for long-term protection. Immune response to SARS-CoV-2 infection was analysed in 57 IC and 15 solid organ transplanted (TX) patients. Antibody responses were determined by ELISA and neutralization assay. T-cell response was determined by stimulation with peptide pools of the Spike, Envelope, Membrane, and Nucleocapsid proteins with a 20-h Activation Induced Marker (AIM) and 7-day lymphoproliferative assays. Antibody response was detected at similar levels in IC and TX patients. Anti-Spike IgG, IgA and neutralizing antibodies persisted for at least one year, while anti-Nucleocapsid IgG declined earlier. Patients with pneumonia developed higher antibody levels than patients with mild symptoms. Similarly, both rapid and proliferative T-cell responses were detected within the first two months after infection at comparable levels in IC and TX patients, and were higher in patients with pneumonia. T-cell response persisted for at least one year in both IC and TX patients. Spike, Membrane, and Nucleocapsid proteins elicited the major CD4+ and CD8+ T-cell responses, whereas the T-cell response to Envelope protein was negligible. After SARS-CoV-2 infection, antibody and T-cell responses develop rapidly and persist over time in both immunocompetent and transplanted patients.


Subject(s)
Antibodies, Viral/blood , COVID-19/immunology , Immunocompromised Host , Organ Transplantation , SARS-CoV-2/immunology , T-Lymphocytes/immunology , Transplant Recipients , Adult , Aged , Aged, 80 and over , Antibodies, Neutralizing/blood , B-Lymphocytes/immunology , Cell Proliferation , Female , Humans , Male , Memory T Cells/immunology , Middle Aged
16.
Viruses ; 13(11)2021 10 28.
Article in English | MEDLINE | ID: covidwho-1488759

ABSTRACT

We aimed to explore whether variants of SARS-CoV-2 (Chinese-derived strain (D614, lineage A), Italian strain PV10734 (D614G, lineage B.1.1) and Alpha strain (lineage B.1.1.7)) were able to infect monocytes (MN) and monocyte-derived macrophages (MDM) and whether these infected cells may, in turn, be vectors of infection. For this purpose, we designed an in vitro study following the evolution of MN and MDM infection at different time points in order to confirm whether these cells were permissive for SARS-CoV-2 replication. Finally, we investigated whether, regardless of viral replication, the persistent virus can be transferred to non-infected cells permissive for viral replication. Thus, we co-cultured the infected MN/MDM with permissive VERO E6 cells verifying the viral transmission. This is a further in vitro demonstration of the important role of MN and MDM in the dissemination of SARS-CoV-2 and evolution of the COVID-19 disease.


Subject(s)
Macrophages/virology , Monocytes/virology , SARS-CoV-2/physiology , Animals , Chlorocebus aethiops , Coculture Techniques , Coronavirus Nucleocapsid Proteins/metabolism , Humans , Macrophages/ultrastructure , Monocytes/ultrastructure , Phosphoproteins/metabolism , Spike Glycoprotein, Coronavirus/metabolism , Vero Cells , Virus Internalization , Virus Replication
17.
Clin Microbiol Infect ; 28(2): 301.e1-301.e8, 2022 Feb.
Article in English | MEDLINE | ID: covidwho-1474453

ABSTRACT

OBJECTIVES: To assess the humoral and cell-mediated response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) elicited by the mRNA BNT162b2 vaccine in SARS-CoV-2-experienced and -naive subjects against a reference strain and SARS-CoV-2 variants. METHODS: The humoral response (including neutralizing antibodies) and T-cell-mediated response elicited by BNT162b2 vaccine in 145 healthcare workers (both naive and positive for previous SARS-CoV-2 infection) were evaluated. In a subset of subjects, the effect of SARS-CoV-2 variants on antibody level and cell-mediated response was also investigated. RESULTS: Overall, 125/127 naive subjects (98.4%) developed both neutralizing antibodies and specific T cells after the second dose of vaccine. Moreover, the antibody and T-cell responses were effective against viral variants since SARS-CoV-2 NT Abs were still detectable in 55/68 (80.9%) and 25/29 (86.2%) naive subjects when sera were challenged against ß and δ variants, respectively. T-cell response was less affected, with no significant difference in the frequency of responders (p 0.369). Of note, two doses of vaccine were able to elicit sustained neutralizing antibody activity against all the SARS-CoV-2 variants tested in SARS-CoV-2-experienced subjects. CONCLUSIONS: BNT162b2 vaccine elicited a sustained humoral and cell-mediated response in immunocompetent subjects after two-dose administration of the vaccine, and the response seemed to be less affected by SARS-CoV-2 variants, the only exceptions being the ß and δ variants. Increased immunogenicity, also against SARS-CoV-2 variant strains, was observed in SARS-CoV-2-experienced subjects. These results suggest that triple exposure to SARS-CoV-2 antigens might be proposed as valuable strategy for vaccination campaigns.


Subject(s)
COVID-19 , SARS-CoV-2 , Antibodies, Viral , BNT162 Vaccine , COVID-19 Vaccines , Health Personnel , Humans , Vaccination , Vaccines, Synthetic , mRNA Vaccines
18.
Nat Commun ; 12(1): 6032, 2021 10 15.
Article in English | MEDLINE | ID: covidwho-1469967

ABSTRACT

Vaccine breakthrough SARS-CoV-2 infection has been monitored in 3720 healthcare workers receiving 2 doses of BNT162b2. SARS-CoV-2 infection is detected in 33 subjects, with a 100-day cumulative incidence of 0.93%. Vaccine protection against acquisition of SARS-CoV-2 infection is 83% (95%CI: 58-93%) in the overall population and 93% (95%CI: 69-99%) in SARS-CoV-2-experienced subjects, when compared with a non-vaccinated control group from the same Institution, in which SARS-CoV-2 infection occurs in 20/346 subjects (100-day cumulative incidence: 5.78%). The infection is symptomatic in 16 (48%) vaccinated subjects vs 17 (85%) controls (p = 0.01). All analyzed patients, in whom the amount of viral RNA was sufficient for genome sequencing, results infected by the alpha variant. Antibody and T-cell responses are not reduced in subjects with breakthrough infection. Evidence of virus transmission, determined by contact tracing, is observed in two (6.1%) cases. This real-world data support the protective effect of BNT162b2 vaccine. A triple antigenic exposure, such as two-dose vaccine schedule in experienced subjects, may confer a higher protection.


Subject(s)
Asymptomatic Infections/epidemiology , COVID-19 Vaccines/administration & dosage , COVID-19/diagnosis , Health Personnel/statistics & numerical data , SARS-CoV-2/pathogenicity , Antibodies, Viral/blood , BNT162 Vaccine , COVID-19/epidemiology , COVID-19/prevention & control , COVID-19/virology , COVID-19 Nucleic Acid Testing/statistics & numerical data , Case-Control Studies , Female , Humans , Immunization Schedule , Incidence , Male , Prospective Studies , RNA, Viral/genetics , RNA, Viral/isolation & purification , SARS-CoV-2/genetics , SARS-CoV-2/immunology , SARS-CoV-2/isolation & purification , Severity of Illness Index
19.
Biomedicines ; 9(10)2021 Sep 22.
Article in English | MEDLINE | ID: covidwho-1438507

ABSTRACT

COVID-19 related morbidity and mortality have been often attributed to an exaggerated immune response. The role of cytokines and chemokines in COVID-19 and their contributions to illness severity are known, and thus their profiling from patient bronchoalveolar lavage (BAL) samples would help in understanding the disease progression. To date, limited studies have been performed on COVID-19 BAL samples, as the manipulation of such specimens (potentially containing live viruses) requires several laboratorial precautions, such as personnel training and special equipment, a requirement that not all laboratories can fulfil. Here, we assessed two fast and easily applicable methods (ultrafiltration and ultraviolet-C irradiation) for their impact on viral load removal or inactivation, respectively and on cytokine profiles preservation. Eight samples of BAL fluids from SARS-CoV2 patients with high viral load were tested. For both methods, complete removal was confirmed by lack of viral replication in Vero E6 cells and by RT-qPCR. Although both methods showed to remove completely the active SARS-CoV2 viral load, only UVC treatment has little or no quantitative effect on total cytokines/chemokines measurements, however cytokines profile and relative ratios are preserved or minimally altered when compared data obtained by the two different decontamination methods. Sample preparation and manipulation can greatly affect the analytical results; therefore, understanding if changes occurred after sample processing is of outmost importance for reliable data and can be useful to improve clinical practice.

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