ABSTRACT
Importance Investigating the role of pre-infection humoral immunity against Omicron BA.5 infection risk and long COVID development is critical to inform public health guidance. Objective To investigate the association between pre-infection immunogenicity after the third vaccine dose and the risks of Omicron BA.5 infection and long coronavirus disease. Design, Setting, and Participants This nested case-control analysis was conducted among tertiary hospital staff in Tokyo, Japan who donated blood samples in June 2022 (1 month before Omicron BA.5 dominant wave onset [July-September 2022]) approximately 6 months after receiving the third dose of the historical monovalent coronavirus disease 2019 mRNA vaccine. Exposures Live virus-neutralizing antibody titers against Wuhan and Omicron BA.5 (NT50) and anti-SARS-CoV-2 spike protein antibody titers with Abbott (AU/mL) and Roche (U/mL) assays at pre-infection. Main Outcomes and Measures Symptomatic SARS-CoV-2 breakthrough infections during the Omicron BA.5 dominant wave vs. undiagnosed controls matched using a propensity score. Incidence of long COVID (persistent symptoms [≥]4 weeks after infection) among breakthrough infection cases. Results Anti-spike antibody titers were compared between 243 breakthrough infection cases and their matched controls among the 2360 staff members who met the criteria. Neutralizing antibodies in 50 randomly selected matched pairs were measured and compared. Pre-infection anti-spike and neutralizing antibody titers were lower in breakthrough cases than in undiagnosed controls. Neutralizing antibody titers against Wuhan and Omicron BA.5 were 64% (95% CI: 42-77) and 72% (95% CI: 53-83) lower, respectively, in breakthrough cases than in undiagnosed controls. Individuals with previous SARS-CoV-2 infections were more frequent among undiagnosed controls than breakthrough cases (19.3% vs. 4.1%), and their neutralizing antibody titers were higher than those of infection-naive individuals. Among the breakthrough cases, pre-infection antibody titers were not associated with the incidence of long COVID. Conclusions and Relevance Pre-infection immunogenicity against SARS-CoV-2 may play a role in protecting against the Omicron BA.5 infection, but not in preventing long COVID.
Subject(s)
Coronavirus Infections , Severe Acute Respiratory Syndrome , Breakthrough Pain , COVID-19ABSTRACT
Background Data on the role of immunogenicity following the third vaccine dose against Omicron infection and coronavirus disease 2019 (COVID-19)-compatible symptoms of infection are limited. Methods First we examined vaccine effectiveness (VE) of the third-dose against the second dose during the Omicron wave among the staff at a tertiary hospital in Tokyo. In a case-control study of a cohort of third vaccine recipients, we compared the pre-infection levels of live-virus neutralizing antibodies (NAb) against Omicron between breakthrough cases and their controls, who had close contact with COVID-19 patients. Among these cases, we examined the association between pre-infection NAb levels and the number of COVID-19-compatible symptoms experienced during the Omicron wave. Results Among the 1456 participants for VE analysis, 60 (4%) breakthrough infections occurred during the Omicron wave (January to March 2022). The third-dose VE for infection, relative to the second dose was 54.6% (95% CI: 14.0-76.0). Among the recipients of the third vaccine, pre-infection NAb levels against Omicron did not significantly differ between the cases and controls. Among the cases, those who experienced COVID-19-compatible symptoms had lower pre-infection NAb levels against Omicron than those who did not. Conclusions The third vaccine dose was effective in decreasing the risk of severe acute respiratory syndrome coronavirus 2 infection during the Omicron wave compared with the second dose. Among third-dose recipients, higher pre-infection NAb levels may not be associated with a lower risk of Omicron infection. Contrarily, they may be associated with fewer symptoms of infection.
Subject(s)
Coronavirus Infections , Breakthrough Pain , COVID-19ABSTRACT
Background Longitudinal data are lacking to compare booster effects of Delta breakthrough infection versus the third vaccine dose on neutralizing antibodies (NAb) against Omicron. Methods Participants were the staff of a national research and medical institution in Tokyo who attended serological surveys on June 2021 (baseline) and December 2021 (follow-up); in between, the Delta-dominant epidemic occurred. Of 844 participants who were infection-naive and had received two doses of BNT162b2 at baseline, we identified 11 breakthrough infections during the follow-up. One control matched to each case was randomly selected from those who completed the booster vaccine and those who were unboosted by the follow-up. We used the generalized estimating equation model to compare live-virus NAb against Wuhan, Delta, and Omicron across groups. Results Persons who experienced breakthrough infection showed marked increases in NAb titers against Wuhan (4.1-fold) and Delta (5.5-fold), and 64% had detectable NAb against Omicron at follow-up, although the NAb against Omicron after breakthrough infection was 6.7- and 5.2-fold lower than that against Wuhan and Delta, respectively. The increase was apparent only in symptomatic cases and as high as in the third vaccine recipients. In contrast, these titers largely decreased (Wuhan, Delta) or remained undetected (Omicron) at follow-up in infection-naive and unboosted persons. Conclusions Symptomatic breakthrough infection during the Delta predominant wave was associated with significant increases in NAb against Wuhan, Delta, and Omicron, similar to the third BNT162b2 vaccine. Given the much lower cross-NAb against Omicron than other virus types, however, infection prevention measures must be continued irrespective of vaccine and infection history while the immune evasive variants are circulating.
Subject(s)
Breakthrough PainABSTRACT
Secretory immunoglobulin A (IgA) plays a crucial role in the mucosal immunity for preventing the invasion of the exogenous antigens, however, little has been understood about the neutralizing activity of serum IgA. Here, to examine the role of IgA antibodies against COVID-19 illnesses, we determined the neutralizing activity of serum/plasma IgG and IgA purified from previously SARS-CoV-2-infected and COVID-19 mRNA-vaccine-receiving individuals. We found that serum/plasma IgA possesses substantial but rather modest neutralizing activity against SARS-CoV-2 compared to IgG with no significant correlation with the disease severity. Neutralizing IgA and IgG antibodies achieved the greatest activity at approximately 25 and 35 days after symptom onset, respectively. However, neutralizing IgA activity quickly diminished and went down below the detection limit approximately 70 days after onset, while substantial IgG activity was observed till 200 days after onset. The total neutralizing activity in sera/plasmas of those with COVID-19 largely correlated with that in purified-IgG and purified-IgA and levels of anti-SARS-CoV-2-S1-binding IgG and anti-SARS-CoV-2-S1-binding IgA. In individuals who were previously infected with SARS-CoV-2 but had no detectable neutralizing IgA activity, a single dose of BNT162b2 or mRNA-1273 elicited potent serum/plasma neutralizing IgA activity but the second dose did not further strengthen the neutralization antibody response. The present data show that the systemic immune stimulation with natural infection and COVID-19 mRNA-vaccines elicit both SARS-CoV-2-specific neutralizing IgG and IgA response in serum, but the IgA response is modest and diminishes faster compared to IgG response.
Subject(s)
COVID-19 , Severe Acute Respiratory SyndromeABSTRACT
In the present prospective study, 225 individuals in Kumamoto General Hospital, Japan, who received two-doses of BNT162b2 vaccine were enrolled/followed up over 150 days. Neutralizing activity (NT50) of sera on day-60 post-1st -dose against wild-type (SARS-CoV-2Wuhan)(n = 211) and 9 variants (VOCs; Alpha/Beta/Gamma/Delta, and VUM; Kappa)(n = 45) were examined. Also, antiviral activity (EC50) of IgG obtained from day-60 sera against SARS-CoV-2Wuhan and 9 variants were evaluated (n = 45). Finally, time-dependent alterations of IgG-activity (n = 25) against SARS-CoV-2Wuhan/variants were examined. Day-60 sera showed reduced NT50 by more than 50% against all variants, and greatest reduction was seen with Beta. IgG of high-responders (IgGhighs) and moderate-responders (IgGmoderates) showed similar fold-changes in EC50 against each variant compared to SARS-CoV-2Wuhan. However, absolute EC50 of IgGhighs were 2 ~ 3-folds greater than those of IgGmoderates against all SARS-CoV-2s. Evaluation of EC50 of IgG obtained at different time-points (day-28 to -150) revealed time-dependent reduction of IgG-activity against various VOCs/VUM. However, against Delta, relatively long-lasting favorable EC50 (at least 150 days) of both IgG were observed. Our data strongly suggest that rapid expansion of vaccine administration in Japan was remarkably effective to repress SARS-CoV-2 pandemic with the spread of Delta, and give insights in better understanding of the antiviral-efficacy of SARS-CoV-2 vaccine and vaccine-elicited immune-response.
ABSTRACT
The recent emergence of SARS-CoV-2 Omicron variants possessing large numbers of mutations has raised concerns of decreased effectiveness of current vaccines, therapeutic monoclonal antibodies, and antiviral drugs for COVID-19 against these variants1,2. While the original Omicron lineage, BA.1, has become dominant in many countries, BA.2 has been detected in at least 67 countries and has become dominant in the Philippines, India, and Denmark. Here, we evaluated the replicative ability and pathogenicity of an authentic infectious BA.2 isolate in immunocompetent and human ACE2 (hACE2)-expressing mice and hamsters. In contrast to recent data with chimeric, recombinant SARS-CoV-2 strains expressing the spike proteins of BA.1 and BA.2 on an ancestral WK-521 backbone3, we observed similar infectivity and pathogenicity in mice and hamsters between BA.2 and BA.1, and less pathogenicity compared to early SARS-CoV-2 strains. We also observed a marked and significant reduction in the neutralizing activity of plasma from COVID-19 convalescent individuals and vaccine recipients against BA.2 compared to ancestral and Delta variant strains. In addition, we found that some therapeutic monoclonal antibodies (REGN10987/REGN10933, COV2-2196/COV2-2130, and S309) and antiviral drugs (molnupiravir, nirmatrelvir, and S-217622) can restrict viral infection in the respiratory organs of hamsters infected with BA.2. These findings suggest that the replication and pathogenicity of BA.2 is comparable to that of BA.1 in rodents and that several therapeutic monoclonal antibodies and antiviral compounds are effective against Omicron/BA.2 variants.
Subject(s)
COVID-19ABSTRACT
BNT162b2, an mRNA-based SARS-CoV-2 vaccine (Pfizer-BioNTech), is one of the most effective COVID-19 vaccines and has been approved by more than 130 countries worldwide. However, several studies have reported that the COVID-19 vaccine shows high interpersonal variability in terms of humoral and cellular responses, such as those with respect to SARS-CoV-2 spike protein immunoglobulin (Ig)G, IgA, IgM, neutralizing antibodies, and CD4 + & CD8 + T cells. The objective of this study is to investigate the kinetic changes in anti-SARS-CoV-2 spike IgG (IgG-S) profiles and adverse reactions and their associations with HLA profiles among 100 hospital workers from the Center Hospital of the National Center for Global Health and Medicine (NCGM), Tokyo, Japan. DQA1*03:03:01 (P = 0.017; Odd ratio (OR) 2.80, 95%Confidence interval (CI) 1.05–7.25) was significantly associated with higher IgG-S production after two doses of BNT162b2 while DQB1*06:01:01:01 (P = 0.028, OR 0.27, 95%CI 0.05–0.94) was significantly associated with IgG-S declines after two doses of BNT162b2. No HLA alleles were significantly associated with either local symptoms or fever. However, C*12:02:02 (P = 0.058; OR 0.42, 95%CI 0.15–1.16), B*52:01:01 (P = 0.031; OR 0.38, 95%CI 0.14–1.03), DQA1*03:02:01 (P = 0.028; OR 0.39, 95%CI 0.15–1.00) and DPB1*02:01:02 (P = 0.024; OR 0.45, 95%CI 0.21–0.97) appeared significantly associated with protection against systemic symptoms after two doses of BNT162b2 vaccination. Further studies with larger sample sizes are clearly warranted to determine HLA allele associations with the production and long-term sustainability of IgG-S after COVID-19 vaccination.
Subject(s)
Fever , COVID-19ABSTRACT
Background. The humoral and cellular immune responses against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) upon coronavirus disease 2019 (COVID-19) vaccination remain to be clarified. Hence, we aimed to investigate the chronological changes in SARS-CoV-2 specific IgG antibody, neutralizing antibody, and T cell responses during and after receiving the BNT162b2 vaccine. Methods. We performed serological, neutralization, and T cell assays among 100 hospital workers aged 22-73 years who received the vaccine. We conducted five surveys on day 1, day 15, day 29 (seven days after the second dose), day 61, and days 82-96 following the first dose. Results. SARS-CoV-2 spike protein-specific IgG (IgG-S) titers and T cell responses increased significantly following the first vaccination dose. The highest titers were observed on day 29 and decreased gradually until the end of the follow-up period. There was no correlation between IgG-S and T cell responses. Notably, T cell responses were detected on day 15, earlier than the onset of neutralizing activity. Conclusions. This study demonstrated that both IgG-S and T cell responses were detected before acquiring sufficient levels of SARS-CoV-2 neutralizing antibodies. These early immune responses are sustained for approximately six-ten weeks following the second vaccination dose.
Subject(s)
Coronavirus Infections , COVID-19 , Protein S DeficiencyABSTRACT
Background: While increasing coverage of effective vaccines against coronavirus disease 2019 (COVID-19), emergent variants raise concerns about breakthrough infections. Data are limited, however, whether breakthrough infection during the epidemic of the variant is ascribed to insufficient vaccine-induced immunogenicity. Methods: We described incident COVID-19 in relation to the vaccination program among workers of a referral hospital in Tokyo. During the predominantly Delta epidemic, we followed 2,473 fully vaccinated staff (BNT162b2) for breakthrough infection and selected three matched controls. We measured pre-infection neutralizing antibodies against the wild-type, Alpha (B.1.1.7), and Delta (B.1.617.2) strains using live viruses and anti-spike antibodies using quantitative assays, and compared them using the generalized estimating equation model between the two groups. Results: No COVID-19 cases occurred 1-2 months after the vaccination program during the fourth epidemic wave in Japan, dominated by the Alpha variant, while 22 cases emerged 2-4 months after the vaccination program during the fifth wave, dominated by the Delta variant. In the vaccinated cohort, all 17 cases of breakthrough infection were mild or asymptomatic and had returned to work early. There was no measurable difference between cases and controls in pre-infection neutralizing antibody titers against the wild-type, Alpha, and Delta, and anti-spike antibody titers, while neutralizing titers against the variants were considerably lower than those against the wild-type. Conclusions: Pre-infection neutralizing antibody titers were not decreased among patients with breakthrough infection under the Delta variant rampage. The result points to the importance of infection control measures in the post-vaccination era, irrespective of immunogenicity profile.
Subject(s)
Breakthrough Pain , COVID-19ABSTRACT
While mRNA vaccines against SARS-CoV-2 are exceedingly effective in preventing symptomatic infection, their immune response features remain to be clarified. In the present prospective study, 225 healthy individuals in Japan, who received two BNT162b2 doses, were enrolled. Correlates of BNT162b2-elicited SARS-CoV-2-neutralizing activity (50% neutralization titer: NT 50 ; assessed using infectious virions) with various determinants were examined and the potency of serums against variants of concerns was determined. Significant rise in NT 50 s was seen in serums on day 28 post-1st dose. A moderate inverse correlation was seen between NT 50 s and ages, but no correlation seen between NT 50 s and adverse effects. NT 50 s and SARS-CoV-2-S1-binding-IgG levels on day 28 post-1st dose and pain scores following the 2nd shot were greater in women than in men. The average half-life of NT 50 s was ~ 68 days and the estimated average time length till the total disappearance of neutralizing activity was ~ 198 days. While serums from elite-responders (NT 50 s > 1,500-fold: the top 4% among the participants) potently to moderately blocked all variants of concerns examined, some serums with low NT 50 s failed to block the B.1.351-beta strain. Since BNT162b2-elicited immunity against SARS-CoV-2 is short, an additional vaccine or other protective measures are needed.
ABSTRACT
Background: While mRNA vaccines against SARS-CoV-2 have been exceedingly effective in preventing symptomatic viral infection, the features of immune response remain to be clarified. Methods: In the present prospective observational study, 225 healthy individuals in Kumamoto General Hospital, Japan, who received two BNT162b2 doses in February 2021, were enrolled. Correlates of BNT162b2-elicited SARS-CoV-2-neutralizing activity (50% neutralization titer: NT50; assessed using infectious virions and live target cells) with SARS-CoV-2-S1-binding-IgG and -IgM levels, adverse effects (AEs), ages, and genders were examined. The average half-life of neutralizing activity and the average time length for the loss of detectable neutralizing activity were determined and the potency of serums against variants of concerns was also determined. Findings: Significant rise in NT50s was seen in serums on day 28 post-1st dose. A moderate inverse correlation was seen between NT50s and ages, but no correlation was seen between NT50s and AEs. NT50s and IgG levels on day 28 post-1st dose and pain scores following the 2nd shot were greater in women than in men. The average half-life of neutralizing activity in the vaccinees was approximately 67.8 days and the average time length for their serums to lose the detectable neutralizing activity was 198.3 days. While serums from elite-responders (NT50s>1,500-fold: the top 4% among all participants' NT50s) potently to moderately blocked the infectivity of variants of concerns, some serums with moderate NT50s failed to block the infectivity of a beta strain. Interpretation: BNT162b2-elicited immune response has no significant association with AEs. BNT162b2-efficacy is likely diminished to under detection limit by 6-7 months post-1st shot. High-level neutralizing antibody-containing serums potently to moderately block the infection of SARS-CoV-2 variants; however, a few moderate-level neutralizing antibody-containing serums failed to do so. If BNT162b2-elicited immunity memory is short, an additional vaccine or other protective measures would be needed.
Subject(s)
PainABSTRACT
Background: While mRNA vaccines against SARS-CoV-2 have been exceedingly effective in preventing symptomatic viral infection, the features of immune response remain to be clarified.Methods: In the present prospective observational study, 225 healthy individuals in Kumamoto General Hospital, Japan, who received two BNT162b2 doses in February 2021, were enrolled. Correlates of BNT162b2-elicited SARS-CoV-2-neutralizing activity (50% neutralization titer: NT50; assessed using infectious virions and live target cells) with SARS-CoV-2-S1-binding-IgG and -IgM levels, adverse effects (AEs), ages, and genders were examined. The average half-life of neutralizing activity and the average time length for the loss of detectable neutralizing activity were determined and the potency of serums against variants of concerns was also determined.Findings: Significant rise in NT50s was seen in serums on day 28 post-1st dose. A moderate inverse correlation was seen between NT50s and ages, but no correlation was seen between NT50s and AEs. NT50s and IgG levels on day 28 post-1st dose and pain scores following the 2nd shot were greater in women than in men. The average half-life of neutralizing activity in the vaccinees was approximately 67.8 days and the average time length for their serums to lose the detectable neutralizing activity was 198.3 days. While serums from elite-responders (NT50s >1,500-fold: the top 4% among all participants’ NT50s) potently to moderately blocked the infectivity of variants of concerns, some serums with moderate NT50s failed to block the infectivity of a beta strain.Interpretation: BNT162b2-elicited immune response has no significant association with AEs. BNT162b2-efficacy is likely diminished to under detection limit by 6-7 months post-1st shot. High-level neutralizing antibody-containing serums potently to moderately block the infection of SARS-CoV-2 variants; however, a few moderate-level neutralizing antibody-containing serums failed to do so. If BNT162b2-elicited immunity memory is short, an additional vaccine or other protective measures would be needed.Funding Information: This research was supported in part by a grant from the Japan Agency for Medical Research and Development to Maeda (grant number JP20fk0108260, 20fk0108502) and to Mitsuya (grant number 20fk0108502), and in part by a grant for MHLW Research on Emerging and Re-emerging Infectious Diseases and Immunization Program to Maeda (grant number JPMH20HA1006) from Ministry of Health, Labor and Welfare, and in part by a grant for COVID-19 to Mitsuya (grant number 19A3001) and Maeda (grant number 20A2003D) from the Intramural Research Program of National Center for Global Health and Medicine, and in part by the Intramural Research Program of the Center for Cancer Research, National Cancer Institute, National Institutes of Health (Mitsuya).Declaration of Interests: Matsushima, Noda, Sato, and Yoshida are employees of SysmexCorporation.Other authors declare that the research was conducted in the absence of any commercial or financial relationship that could be construed as a potential conflict of interest.Ethics Approval Statement: The Ethics Committees from the Kumamoto General Hospital and NCGM approved this study (Kumamoto General Hospital No. 180, and NCGM-G-004176-00, respectively). Each participant provided a written informed consent, and this study abided by the Declaration of Helsinki principles.
Subject(s)
COVID-19 , NeoplasmsABSTRACT
The duration of the necessity of current restrictions and preventive countermeasures against the COVID-19 pandemic is of great concern. While several previous epidemiological studies have discussed controlling the course of the epidemic with regard to social distancing, vaccination, care capacities, and future scenarios, we adopt an alternative approach to provide insights into the time scale of epidemic propagation in human populations. We show that the reproduction number modified by preventive countermeasures R m implies a threshold R~ m to reach the herd immunity level at time T h . While T h varies moderately for large R m , it increases sharply around R m =R~ m , and T h is infinite below R m =R~ m . The transition region for this increase is minute, demonstrating that prevention of infectious diseases must consider the relatively asymptotic nature of their propagation, which varies unpredictably between steady transmission and explosive outbreaks. These results suggest the continuation of preventive countermeasures to suppress the transmission of COVID-19 for many years; if they were discontinued or reduced such that R m exceeded R~ m , the disease would be transmitted throughout the considered community, and the required herd immunity level would be reached within 250 days if R m > 1.6. However, the implementation of vaccination programs could drastically alter this dynamic.
Subject(s)
COVID-19 , Communicable DiseasesABSTRACT
Despite various attempts to treat SARS-CoV-2-infected patients with COVID-19-convalescent plasmas, neither appropriate approach nor clinical utility has been established. We examined the efficacy of administration of highly-neutralizing COVID-19-convalescent plasma (hn-plasmas) and such plasma-derived IgG administration using the Syrian hamster COVID-19 model. Two hn-plasmas, which were in the best 1% of 340 neutralizing-activity-determined convalescent plasma samples, were intraperitoneally administered to SARS-CoV-2-infected hamsters, resulting in significant reduction of viral titers in lungs by up to 32-fold as compared to the viral titers in hamsters receiving control non-neutralizing plasma, while with two moderately neutralizing plasmas (mn-plasmas) administered, viral titer reduction was by up to 6-fold. IgG fractions purified from the two hn-plasmas also reduced viral titers in lungs than those from the two mn-plasmas. The severity of lung lesions seen in hamsters receiving hn-plasmas was minimal to moderate as assessed using micro-computerized tomography, which histological examination confirmed. Western blotting revealed that all four COVID-19-convalescent-plasmas variably contained antibodies against SARS-CoV-2 components including the receptor-binding domain and S1 domain. The present data strongly suggest that administering potent-neutralizing-activity-confirmed COVID-19-convalescent plasmas would be efficacious in treating patients with COVID-19.
Subject(s)
COVID-19 , Severe Acute Respiratory Syndrome , Lung DiseasesABSTRACT
SARS-CoV-2 encodes main protease (Mpro), an attractive target for therapeutic interventions. We show Mpro is susceptible to glutathionylation leading to inhibition of dimerization and activity. Activity of glutathionylated Mpro could be restored with reducing agents or glutaredoxin. Analytical studies demonstrated that glutathionylated Mpro primarily exists as a monomer and that a single modification with glutathione is sufficient to block dimerization and loss of activity. Proteolytic digestions of Mpro revealed Cys300 as a primary target of glutathionylation, and experiments using a C300S Mpro mutant revealed that Cys300 is required for inhibition of activity upon Mpro glutathionylation. These findings indicate that Mpro dimerization and activity can be regulated through reversible glutathionylation of Cys300 and provides a novel target for the development of agents to block Mpro dimerization and activity. This feature of Mpro may have relevance to human disease and the pathophysiology of SARS-CoV-2 in bats, which develop oxidative stress during flight.