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2.
J Infect Dis ; 2022 May 05.
Article in English | MEDLINE | ID: covidwho-1831182

ABSTRACT

The SARS-CoV-2 variant Omicron is now under investigation. We evaluated cross-neutralizing activity against Omicron in COVID-19 convalescent patients (n = 23) who had received two doses of an mRNA vaccination (BNT162b2 or mRNA-1273). Intriguingly, after the second vaccination, the neutralizing antibody titers of subjects against SARS-CoV-2 variants, including Omicron, all became seropositive, and significant fold-increases (21.1-52.0) were seen regardless of the disease severity of subjects. Our findings thus demonstrate that two doses of mRNA vaccination to SARS-CoV-2 convalescent patients can induce cross-neutralizing activity against Omicron.

3.
JAMA Netw Open ; 5(5): e2210780, 2022 05 02.
Article in English | MEDLINE | ID: covidwho-1825764

ABSTRACT

Importance: Although 2 and 3 doses of vaccine have been implemented against the SARS-CoV-2 pandemic, the level of immunity achieved by these additional vaccinations remains unclear. Objective: To investigate the induction of neutralizing antibodies against the SARS-CoV-2 Omicron variant after 2 and 3 doses of the BNT162b2 messenger RNA (mRNA) vaccine among recipients of different ages. Design, Setting, and Participants: A cohort study was conducted from June 1, 2021, to January 12, 2022, among 82 physicians at Kobe University Hospital who had received 2 doses of the BNT162b2 mRNA vaccine. Main Outcomes and Measures: The rates of positive test results and the titers of neutralizing antibodies against the Omicron variant after 2 and 3 doses of the vaccine were compared with those against other variants and compared among 3 age groups (≤38 years [younger age group], 39-58 years [intermediate age group], and ≥59 years [older age group]). Results: A total of 82 physicians (71 men [87%]; median age, 44 years [IQR, 33-58 years]) participated; 31 (38%) were in the younger age group, 32 (39%) were in the intermediate age group, and 19 (23%) were in the older age group. At 2 months after 2 doses of the vaccine, 23 participants (28%) had neutralizing antibodies against the Omicron variant, with a titer of 1.3 (95% CI, 1.2-1.4), which was 11.8-fold (95% CI, 9.9-13.9) lower than the titer against the D614G variant and the lowest among the variants tested. Although the titer of the neutralizing antibody against the Delta variant tended to be low among the older age group (2.9 [95% CI, 2.0-4.1]), the titers of the neutralizing antibody against the Omicron variant were low among all age groups (younger age group, 1.3 [95% CI, 1.1-1.6]; intermediate age group, 1.3 (95% CI, [95% CI, 1.1-1.5]; and older age group, 1.2 [95% CI, 1.0-1.4]). At 7 months after 2 doses of the vaccine, 5 participants (6%) had the neutralizing antibody against the Omicron variant, but after the booster (third dose) vaccination, all 72 participants who received the booster had the neutralizing antibody, and the titer was 41 (95% CI, 34-49), much higher than that at 7 months after 2 doses of the vaccine (1.0 [95% CI, 1.0-1.1]). This increase in titers was observed regardless of age groups; the titers were 44 (95% CI, 32-59) among the younger age group, 44 (95% CI, 32-59) among the intermediate age group, and 30 (95% CI, 22-41) among the older age group. Conclusions and Relevance: In this cohort study of 82 Japanese participants, 2 doses of the BNT162b2 mRNA vaccine did not induce sufficient neutralizing antibody against the Omicron variant. However, booster vaccination was associated with induction of a high level of neutralizing antibodies against the Omicron variant, irrespective of the recipient's age.


Subject(s)
COVID-19 , SARS-CoV-2 , Adult , Aged , Antibodies, Neutralizing , Antibodies, Viral , BNT162 Vaccine , COVID-19/prevention & control , COVID-19 Vaccines , Cohort Studies , Female , Humans , Male , Middle Aged , RNA, Messenger , Vaccines, Synthetic , mRNA Vaccines
4.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-334224

ABSTRACT

The VOC of SARS-CoV-2, Omicron (BA.1, BA.1.1, BA.2, or BA.3), is associated with an increased risk of reinfection. BA.2 has become the next dominant variant worldwide. Although BA.2 infection has been shown to be mild illness, its high transmissibility will result in high numbers of cases. In response to the surge of Omicron BA.1 cases, booster vaccination was initiated in many countries. But there is limited evidence regarding the effectiveness of a booster vaccination against BA.2. We collected blood samples from 84 physicians at Kobe University Hospital, Japan, in January 2022 ∼7 months after they had received two BNT162b2 vaccinations and ∼2 weeks after their booster vaccination. We performed a serum neutralizing assay against BA.2 using authentic virus. Although most of the participants had no or a very low titer of neutralizing antibody against BA.2 at 7 months after two BNT162b2 vaccinations, the titer increased significantly at 2 weeks after the booster vaccination.

6.
PLoS One ; 17(4): e0266270, 2022.
Article in English | MEDLINE | ID: covidwho-1775458

ABSTRACT

Continuous appearance of SARS-CoV-2 variants and mass vaccination have been intricately influencing on the COVID-19 situation. To elucidate the current status in Japan, we analyzed totally 2,000 sera in August (n = 1,000) and December (n = 1,000) 2021 collected from individuals who underwent a health check-up. The anti-N seropositive rate were 2.1% and 3.9% in August and December 2021, respectively, demonstrating a Delta variant endemic during that time; it was approximately twofold higher than the rate based on the PCR-based diagnosis. The anti-S seropositive rate was 38.7% in August and it reached 90.8% in December, in concordance with the vaccination rate in Japan. In the December cohort, 78.7% of the sera showed neutralizing activity against the Delta variant, whereas that against the Omicron was much lower at 36.6%. These analyses revealed that effective immunity against the Delta variant was established in December 2021, however, prompt three-dose vaccination is needed to overcome Omicron's outbreak.


Subject(s)
COVID-19 , SARS-CoV-2 , Antibodies, Neutralizing , COVID-19/epidemiology , COVID-19/prevention & control , Humans , Japan/epidemiology , Vaccination
7.
Sci Rep ; 12(1): 4835, 2022 03 22.
Article in English | MEDLINE | ID: covidwho-1758370

ABSTRACT

To halt the pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), governments around the world have imposed policies, such as lockdowns, mandatory mask wearing, and social distancing. The application of disinfecting materials in shared public facilities can be an additional measure to control the spread of the virus. Copper is a prominent material with antibacterial and antiviral effects. In this study, we synthesized copper nanoparticles (CuNPs) as a surface coating agent and assessed their antiviral activity against SARS-CoV-2. CuNPs with a mean size of 254 nm in diameter were synthesized from copper sulfate as a source and were predominantly composed of copper oxide. The synthesized CuNPs were mixed with resin-based paint (CuNP/paint) and sprayed on the surface of stainless steel remnants. SARS-CoV-2 lost 97.8% infectivity on the CuNP/paint-coated surface after 30 min of exposure and more than 99.995% infectivity after 1 h of exposure. The inactivation rate was approximately 36-fold faster than that on the paint alone-coated and uncoated surfaces. The CuNP/paint-coated surface showed powerful inactivation of SARS-CoV-2 infectivity, although further study is needed to elucidate the inactivation mechanisms. Applications of CuNP/paint coatings to public or hospital facilities and other commonly touched areas are expected to be beneficial.


Subject(s)
COVID-19 , Nanoparticles , Antiviral Agents/pharmacology , Antiviral Agents/therapeutic use , Communicable Disease Control , Copper , Humans , SARS-CoV-2
8.
Front Immunol ; 13: 773652, 2022.
Article in English | MEDLINE | ID: covidwho-1742214

ABSTRACT

Background: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is the virus responsible for the Coronavirus Disease 2019 (COVID-19) pandemic. The emergence of variants of concern (VOCs) has become one of the most pressing issues in public health. To control VOCs, it is important to know which COVID-19 convalescent sera have cross-neutralizing activity against VOCs and how long the sera maintain this protective activity. Methods: Sera of patients infected with SARS-CoV-2 from March 2020 to January 2021 and admitted to Hyogo Prefectural Kakogawa Medical Center were selected. Blood was drawn from patients at 1-3, 3-6, and 6-8 months post onset. Then, a virus neutralization assay against SARS-CoV-2 variants (D614G mutation as conventional strain; B.1.1.7, P.1, and B.1.351 as VOCs) was performed using authentic viruses. Results: We assessed 97 sera from 42 patients. Sera from 28 patients showed neutralizing activity that was sustained for 3-8 months post onset. The neutralizing antibody titer against D614G significantly decreased in sera of 6-8 months post onset compared to those of 1-3 months post onset. However, the neutralizing antibody titers against the three VOCs were not significantly different among 1-3, 3-6, and 6-8 months post onset. Discussion: Our results indicate that neutralizing antibodies that recognize the common epitope for several variants may be maintained for a long time, while neutralizing antibodies having specific epitopes for a variant, produced in large quantities immediately after infection, may decrease quite rapidly.


Subject(s)
COVID-19/immunology , SARS-CoV-2/physiology , Aged , Antibodies, Viral/blood , Broadly Neutralizing Antibodies , Cross Reactions , Female , Humans , Immunity, Humoral , Immunodominant Epitopes/immunology , Male , Middle Aged , Time Factors
9.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-329141

ABSTRACT

The SARS-CoV-2 variant Omicron is now under investigation. We evaluated cross-neutralizing activity against Omicron in COVID-19 convalescent patients (n=23) who had received two doses of an mRNA vaccination (BNT162b2 or mRNA-1273). Surprisingly and interestingly, after the second vaccination, the subjects’ neutralizing antibody titers including that against Omicron all became seropositive, and significant fold-increases (21.1–52.0) were seen regardless of the subjects’ disease severity. Our findings thus demonstrate that at least two doses of mRNA vaccination to SARS-CoV-2 convalescent patients can induce cross-neutralizing activity against Omicron.

10.
EuropePMC;
Preprint in English | EuropePMC | ID: ppcovidwho-327141

ABSTRACT

To investigate the induction of neutralizing antibodies against Omicron after two and three vaccine doses in recipients of different ages. Physicians at Kobe University Hospital who had received the second dose of the BNT162b2 mRNA vaccine. At 2 months after the second vaccinations, the positive rate of neutralizing antibody against Omicron was 28%, and the titer was significantly lower than those against other variants, 11.8-fold and 3.6-fold lower than those against D614G and Delta, respectively. Unlike Delta, that positive rates of neutralizing antibody against Omicron were low in all age groups, and there was no significant difference in titers among age groups. Seven months after the 2nd dose, the positive rate of neutralizing antibody against Omicron decreased to 6%, but after the booster,3rd vaccination, it increased to 100%, and the titer was much higher than those at 2 and 7 months post-vaccination, 32-fold and 39-fold respectively. The booster vaccination effect was also observed in the younger at 41-fold, middle-aged at 43-fold, and older at 27-fold groups compared to the 7-month titers. Surprisingly, higher-than-predicted titers of the neutralizing antibodies against Omicron were induced after the booster vaccination regardless of recipient age, while this effect was not observed after two doses, indicating the induction of antibodies against common epitopes by the booster vaccination. Three doses can be confidently recommended to suppress the pandemic.

11.
Open Forum Infect Dis ; 8(10): ofab430, 2021 Oct.
Article in English | MEDLINE | ID: covidwho-1462455

ABSTRACT

BACKGROUND: As of March 2021, Japan is facing a fourth wave of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. To prevent further spread of infection, sera cross-neutralizing activity of patients previously infected with conventional SARS-CoV-2 against novel variants is important but has not been firmly established. METHODS: We investigated the neutralizing potency of 81 coronavirus disease 2019 (COVID-19) patients' sera from the first to fourth waves of the pandemic against SARS-CoV-2 D614G, B.1.1.7, P.1, and B.1.351 variants using their authentic viruses. RESULTS: Most sera had neutralizing activity against all variants, showing similar activity against B.1.1.7 and D614G, but lower activity especially against B.1.351. In the fourth wave, sera-neutralizing activity against B.1.1.7 was significantly higher than that against any other variants, including D614G. The sera-neutralizing activity in less severe patients was lower than that of more severe patients for all variants. CONCLUSIONS: The cross-neutralizing activity of convalescent sera was effective against all variants but was potentially weaker for B.1.351. The high neutralizing activity specific to B.1.1.7 in the fourth wave suggests that mutations in the virus might cause conformational change of its spike protein, which affects immune recognition of D614G. Our results indicate that individuals who recover from COVID-19 could be protected from the severity caused by infection with newly emerging variants.

12.
PLoS One ; 16(5): e0251234, 2021.
Article in English | MEDLINE | ID: covidwho-1218428

ABSTRACT

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to a global pandemic, including Indonesia. However, there are only limited data regarding the precise prevalence of the COVID-19 pandemic in Indonesia. Here, to estimate the magnitude of SARS-CoV-2 infection in East Java, Indonesia, we investigated the prevalence of immunoglobulin G (IgG) antibodies. We enrolled 1,819 individuals from June to December 2020 and observed that the subjects' overall prevalence of IgG antibody to SARS-CoV-2 was 11.4% (207/1,819). The prevalence of anti-SARS-CoV-2 antibodies differed significantly between the job/occupation groups (P = 0.0001). A greater prevalence of IgG was detected in laboratory technicians (who take samples from suspected cases and deal with polymerase chain reaction [PCR] procedures, 22.2%) compared to medical personnel who see and take direct care of patients with COVID-19 (e.g., physicians and nurses, 6.0%), other staff in medical facilities (2.9%), general population (12.1%) and non-COVID-19 patients (14.6%). The highest prevalence among age groups was in the 40-49-year-olds (14.8%), and the lowest prevalence was in the 20-29-year-olds (7.4%). However, the younger population still showed a higher prevalence than generally reported, suggesting greater exposure to the virus but less susceptibility to the disease. A geographical difference was also observed: a higher prevalence in Surabaya (13.1%) than in Jombang (9.9%). In conclusion, the COVID-19 outbreak among asymptomatic populations was characterized by a high prevalence of infection in East Java, Indonesia.


Subject(s)
COVID-19/epidemiology , Adolescent , Adult , Antibodies, Viral/blood , COVID-19/blood , COVID-19/diagnosis , Female , Humans , Immunoglobulin G/blood , Indonesia/epidemiology , Male , Middle Aged , SARS-CoV-2/isolation & purification , Seroepidemiologic Studies , Young Adult
13.
J Infect Dis ; 223(7): 1145-1149, 2021 04 08.
Article in English | MEDLINE | ID: covidwho-1174909

ABSTRACT

Most patients with coronavirus disease 2019 (COVID-19) experience asymptomatic disease or mild symptoms, but some have critical symptoms requiring intensive care. It is important to determine how patients with asymptomatic or mild COVID-19 react to severe acute respiratory syndrome coronavirus 2 infection and suppress virus spread. Innate immunity is important for evasion from the first virus attack, and it may play an important role in the pathogenesis in these patients. We measured serum cytokine levels in 95 patients with COVID-19 during the infection's acute phase and report that significantly higher interleukin 12 and 2 levels were induced in patients with asymptomatic or mild disease than in those with moderate or severe disease, indicating the key roles of these cytokines in the pathogenesis of asymptomatic or mild COVID-19.


Subject(s)
COVID-19/immunology , Immunity, Innate , Interleukin-12/blood , Interleukin-2/blood , SARS-CoV-2/immunology , Adolescent , Adult , Aged , Aged, 80 and over , Asymptomatic Infections , COVID-19/blood , COVID-19/diagnosis , COVID-19/virology , COVID-19 Nucleic Acid Testing , Case-Control Studies , Female , Healthy Volunteers , Humans , Interleukin-12/immunology , Interleukin-2/immunology , Male , Middle Aged , RNA, Viral/isolation & purification , SARS-CoV-2/genetics , SARS-CoV-2/isolation & purification , Severity of Illness Index , Young Adult
14.
JMA J ; 4(1): 41-49, 2021 Jan 29.
Article in English | MEDLINE | ID: covidwho-1081643

ABSTRACT

INTRODUCTION: The coronavirus disease 2019 (COVID-19) pandemic is spreading rapidly all over the world. The Japanese government lifted the state of emergency, announced in April 2020, on May 25, but there are still sporadic clusters. Asymptomatic patients who can transmit severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cause some of these clusters. It is thus urgent to investigate the seroprevalence of antibodies against SARS-CoV-2 and their neutralizing activity. We conducted a cross-sectional study of >10,000 samples at hospitals in Hyogo Prefecture, Japan. METHODS: Between August 6 and October 1, 2020, we collected samples of residual blood from the patients who visited or were admitted to five hospitals and a foundation in Hyogo. We tested the samples for antibodies against SARS-CoV-2 by electrochemiluminescence immunoassay (ECLIA) and chemiluminescent enzyme immunoassay (CLEIA). Sera that were positive by ECLIA or CLEIA were analyzed by an immunochromatographic (IC) test and neutralizing activity assay. RESULTS: We tested 10,377 samples from patients aged between 0 and 99 years old; 27 cases (0.26%) were positive on the ECLIA, and 51 cases (0.49%) were positive on CLEIA. In the 14 cases that tested positive on both ECLIA and CLEIA, the positive rates on the IC test and for neutralizing activity were high (85% and 92%, respectively). In 50 cases (0.48%) that were positive by either ECLIA or CLEIA, the corresponding rates were low (20% and 6%, respectively). The positive rate of neutralizing antibody was 0.15%. CONCLUSIONS: These results indicate that most Hyogo Prefecture residents still do not have antibodies and should avoid the risk of incurring a SARS-CoV-2 infection. Two or more antibody tests should be required for seroepidemiological studies of the antibody for SARS-CoV-2, and a neutralizing activity assay is also essential.

15.
JMA J ; 4(1): 1-7, 2021 Jan 29.
Article in English | MEDLINE | ID: covidwho-1084276

ABSTRACT

Patients with coronavirus disease 2019 (COVID-19) exhibit a wide clinical spectrum ranging from mild respiratory symptoms to critical and fatal diseases, and older individuals are known to be more severely affected. The underlying mechanism of this phenomenon is unknown. A neutralizing antibody against viruses is known to be important to eliminate the virus. In addition, this antibody is induced at high levels in patients with severe COVID-19, followed by a termination of virus replication. Severe COVID-19 patients exhibit high levels of cytokines/chemokines, even after the disappearance of the virus. This indicates that cytokines/chemokines play significant roles in disease severity. These findings also suggest that antiviral therapy (monoclonal antibody and/or convalescent plasma therapy) should be administered early to eliminate the virus, followed by steroid treatment after viral genome disappearance, especially in patients with severe symptoms.

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