Preinfection Neutralizing Antibodies, Omicron BA.5 Breakthrough Infection, and Long COVID: A Propensity Score-Matched Analysis

BACKGROUND

Data are limited on the role of preinfection humoral immunity protection against Omicron BA.5 infection and long coronavirus disease (COVID) development.

METHODS

We conducted nested case-control analysis among tertiary hospital staff in Tokyo who donated blood samples in June 2022 (1 month before Omicron BA.5 wave), approximately 6 months after receiving a third dose of COVID-19 mRNA vaccine. We measured live virus-neutralizing antibody titers against wild type and Omicron BA.5, and anti-receptor-binding domain (RBD) antibody titers at preinfection, and compared them between cases and propensity-matched controls. Among the breakthrough cases, we examined association between preinfection antibody titers and incidence of long COVID.

RESULTS

Preinfection anti-RBD and neutralizing antibody titers were lower in cases than controls. Neutralizing titers against wild type and Omicron BA.5 were 64% (95% confidence interval [CI], 42%-77%) and 72% (95% CI, 53%-83%) lower, respectively, in cases than controls. Individuals with previous Omicron BA.1/BA.2 infections were more frequent among controls than cases (10.3% vs 0.8%), and their Omicron BA.5 neutralizing titers were 12.8-fold higher than infection-naive individuals. Among cases, preinfection antibody titers were not associated with incidence of long COVID.

CONCLUSIONS

Preinfection immunogenicity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may play a role in protecting against the Omicron BA.5 infection but not preventing long COVID.

Durability and determinants of anti-SARS-CoV-2 spike antibodies following the second and third doses of mRNA COVID-19 vaccine

OBJECTIVES

To examine the differences in durability and its determinants of humoral immunity following 2- and 3-dose COVID-19 vaccination.

METHODS

Throughout the pandemic, we evaluated the anti-spike IgG antibody titers of 2- and 3-dose mRNA vaccine recipients over time among the staff of a medical and research center in Tokyo. Linear mixed models were used to estimate trajectories of antibody titers from 14 to 180 days after the last immune-conferred event (vaccination or infection) and compare antibody waning rates across prior infection and vaccination status, and across background factors in infection-naïve participants.

RESULTS

A total of 6901 measurements from 2964 participants (median age, 35 years; 30% male) were analyzed. Antibody waning rate (percentage per 30 days [95% CI]) was slower after 3 doses (25% [23-26]) than 2 doses (36% [35-37]). Participants with hybrid immunity (vaccination and infection) had further slower waning rates: 2-dose plus infection (16% [9-22]); 3-dose plus infection (21% [17-25]). Older age, male sex, obesity, coexisting diseases, immunosuppressant use, smoking, and alcohol drinking were associated with lower antibody titers, whereas these associations disappeared after 3 doses, except for sex (lower in female participants) and immunosuppressant use. Antibody waned slightly faster in older participants, females, and alcohol drinkers after 2 doses, whereas it did not differ after 3 doses across except sex.

DISCUSSION

The 3-dose mRNA vaccine conferred higher durable antibody titers, and previous infection modestly enhanced its durability. The antibody levels at a given time point and waning speed after 2 doses differed across background factors; however, these differences mostly diminished after 3 doses.

Cumulative and undiagnosed SARS-CoV-2 infection among the staff of a medical research centre in Tokyo after the emergence of variants

To describe the trend of cumulative incidence of coronavirus disease 19 (COVID-19) and undiagnosed cases over the pandemic through the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants among healthcare workers in Tokyo, we analysed data of repeated serological surveys and in-house COVID-19 registry among the staff of National Center for Global Health and Medicine. Participants were asked to donate venous blood and complete a survey questionnaire about COVID-19 diagnosis and vaccine. Positive serology was defined as being positive on Roche or Abbott assay against SARS-CoV-2 nucleocapsid protein, and cumulative infection was defined as either being seropositive or having a history of COVID-19. Cumulative infection has increased from 2.0% in June 2021 (pre-Delta) to 5.3% in December 2021 (post-Delta). After the emergence of the Omicron, it has increased substantially during 2022 (16.9% in June and 39.0% in December). As of December 2022, 30% of those who were infected in the past were not aware of their infection. Results indicate that SARS-CoV-2 infection has rapidly expanded during the Omicron-variant epidemic among healthcare workers in Tokyo and that a sizable number of infections were undiagnosed.

Neutralizing antibodies after three doses of the BNT162b2 vaccine, breakthrough infection, and symptoms during the Omicron-predominant wave

OBJECTIVES

To investigate the role of immunogenicity after the third vaccine dose against Omicron infection and COVID-19-compatible symptoms of infection.

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 third vaccine recipients, we compared the preinfection live-virus neutralizing antibodies (NAb) against Omicron between breakthrough cases and their controls who had close contact with patients with COVID-19. Among these cases, we examined the association between NAb levels and the number of COVID-19-compatible symptoms.

RESULTS

Among the 1456 participants for VE analysis, 60 breakthrough infections occurred during the Omicron wave. The third dose VE for infection was 54.6%. Among the third dose recipients, NAb levels against Omicron did not differ between the cases (n = 22) and controls (n = 21). Among the cases, those who experienced COVID-19-compatible symptoms had lower NAb levels against Omicron than those who did not.

CONCLUSION

The third vaccine dose was effective in decreasing the risk of SARS-CoV-2 infection during Omicron wave compared with the second dose. Among third dose recipients, higher preinfection NAb levels may not be associated with a lower risk of Omicron infection. Contrarily, they may be associated with fewer symptoms of infection.

Coronavirus Disease 2019 (COVID-19) Breakthrough Infection and Post-Vaccination Neutralizing Antibodies Among Healthcare Workers in a Referral Hospital in Tokyo: A Case-Control Matching Study

BACKGROUND

While increasing coverage of effective vaccines against coronavirus disease 2019 (COVID-19), emergent variants raise concerns about breakthrough infection. Data are limited, however, whether breakthrough infection during the epidemic of the variant is ascribed to insufficient vaccine-induced immunogenicity.

METHODS

We describe incident COVID-19 in relation to the vaccination program among workers of a referral hospital in Tokyo. During the predominantly Delta epidemic, we followed 2415 fully vaccinated staff (BNT162b2) for breakthrough infection and selected 3 matched controls. We measured post-vaccination 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 2 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 participants had returned to work early. There was no measurable difference between cases and controls in post-vaccination neutralizing antibody titers against the wild-type, Alpha, Delta, and anti-spike antibody titers, while neutralizing titers against the variants were considerably lower than those against the wild-type.

CONCLUSIONS

Post-vaccination neutralizing antibody titers were not decreased among patients with breakthrough infection relative to their controls under the Delta variant outbreak. The result points to the importance of infection-control measures in the post-vaccination era, irrespective of immunogenicity profile.

Importance of HBsAg recognition by HLA molecules as revealed by responsiveness to different hepatitis B vaccines

Hepatitis B (HB) vaccines (Heptavax-II and Bimmugen) designed based on HBV genotypes A and C are mainly used for vaccination against HB in Japan. To determine whether there are differences in the genetic background associated with vaccine responsiveness, genome-wide association studies were performed on 555 Heptavax-II and 1193 Bimmugen recipients. Further HLA imputation and detailed analysis of the association with HLA genes showed that two haplotypes, DRB1*13:02-DQB1*06:04 and DRB1*04:05-DQB1*04:01, were significantly associated in comparison with high-responders (HBsAb > 100 mIU/mL) for the two HB vaccines. In particular, HLA-DRB1*13:02-DQB1*06:04 haplotype is of great interest in the sense that it could only be detected by direct analysis of the high-responders in vaccination with Heptavax-II or Bimmugen. Compared with healthy controls, DRB1*13:02-DQB1*06:04 was significantly less frequent in high-responders when vaccinated with Heptavax-II, indicating that high antibody titers were less likely to be obtained with Heptavax-II. As Bimmugen and Heptavax-II tended to have high and low vaccine responses to DRB1*13:02, 15 residues were found in the Heptavax-II-derived antigenic peptide predicted to have the most unstable HLA-peptide binding. Further functional analysis of selected hepatitis B patients with HLA haplotypes identified in this study is expected to lead to an understanding of the mechanisms underlying liver disease.

Epithelial-myoepithelial carcinomas of the bronchus

Epithelial-myoepithelial carcinomas are very rare in the lung, and little is known about the relationship of their histologic features to prognosis. We describe five primary pulmonary epithelial-myoepithelial carcinomas with details on clinical presentation, histology, and immunohistochemical profiles. We also reviewed the literature to detail further their prognosis. The patients' ages ranged from 33 to 57 years (average 51 years). The tumors were all endobronchial and the patients presented with symptoms or imaging features of airway obstruction. The tumors were completely resected; none showed nodal involvement. All five patients are alive and free of disease 4 months to 8 years (average 4.2 years) after surgery. Four tumors showed a mixed pattern of glands lined by a dual layer of cells and solid sheets of either spindle cells or clear cells, the glandular and solid components being present in variable proportions. The fifth tumor comprised purely spindle cells. The mitotic rate was <1/20 high power fields in both the glandular and spindle/clear cell components. In one case there was focal nuclear pleomorphism. The inner layer of the glands stained for cytokeratins and epithelial membrane antigen, and the outer layer for S-100 and smooth muscle actin. In one case the spindle cells stained for CD34. A review of published cases shows the majority of tumors behave in an indolent fashion, the rare aggressive tumors being predominantly myoepitheliomatous. Nevertheless, the term epithelial-myoepithelial carcinoma is preferred because of their malignant potential. A high mitotic rate, tumoral necrosis, and nuclear pleomorphism appear to be adverse prognostic factors.

[Pulmonary hypertension in a patient with primary Sjogren's syndrome, Hashimoto's disease, and primary biliary cirrhosis]

A 53-year-old woman was admitted to our hospital in May 1999, because of progressive dyspnea and liver dysfunction. She had been receiving the replacement therapy of thyroid hormone for thirteen years and suffering from Raynaud's phenomenon for 9 years. She experienced exertional dyspnea and sicca symptom for 3 years, and had an episode of syncope 4 months before admission. An echocardiogram showed dilation of the right ventricle, tricuspid regurgitation and the estimated mean pressure of the pulmonary artery was higher than 120 mmHg. She was diagnosed as having severe pulmonary hypertension (PH) complicated with primary Sjogren's syndrome and primary biliary cirrhosis without portal hypertension She was treated with anticoagulant (warfarin) and oral prostagrandin I2 (prostacyclin). However, right heart failure and jaundice gradually progressed and she suddenly died in December 1999. At autopsy, the heart was enlarged with right ventricular hypertrophy. Small arteries and arterioles in the lung showed concentric intimal proliferation and severe plexogenic vascular disease. Deposition of immunoglobulin was not observed in the pulmonary arteries. Since the prognosis of PH is poor, it is important to analyze the etiology of the disease for the development of the treatment.

Therapeutic efficiency of IL-2 gene transduced tumor vaccine for head and neck carcinoma

Transduction of the human interleukin-2 (IL-2) gene into tumor cells was carried out in order to develop a new immunotherapy for advanced head and neck carcinomas with a poor outcome. We transduced the IL-2 gene into KB cells, a head and neck squamous cell carcinoma cell line, using a defective herpes simplex viral (HSV) amplicon vector as a gene transfer vehicle. A high level of IL-2 was secreted by IL-2 gene-transduced KB cells (KB/IL-2). The IL-2 producibility of irradiated KB/IL-2 cells was almost the same as that of non-irradiated cells. In the tumor establishment model in nude mice, IL-2 and interferon-gamma (IFN-gamma) at high concentrations were detected in the sera of mice transplanted with KB/IL-2 cells. The spleen cells of nude mice transplanted with KB/IL-2 cells exhibited high cytotoxic activity compared to those from mice transplanted with KB cells and from untreated mice. Three of five mice transplanted with KB/IL-2 cells rejected tumors. In the treatment of established tumors, therapeutic effects due to irradiated KB/IL-2 were dose-dependent. The suppressive effects on tumor growth were blocked by anti-asialo GM1, anti-human IL-2 and anti-IFN-gamma antibodies. Immunohistochemical observation revealed the presence of asialo GM1(+) cells among the KB/IL-2 cells in tumors transplanted into nude mice.

[Pneumonitis in a patient who inhaled a fibrinolysin-deoxyribonuclease mixture]

A 56-year-old man was transferred to our department from the department of oral surgery, with a high fever and a cough. He had inhaled a fibrinolysin-deoxyribonuclease mixture (Elase) to treat inflammation in the oral cavity after resection of an oral tumor. A chest X-ray film showed diffuse patchy shadows in both lung fields. Bronchoalveolar lavage fluid had an abnormally high number of lymphocytes and transbronchial lung biopsy revealed interstitial infiltration by lymphocytes and histiocytes, with granulomatous lesions. The patient was treated with steroids, and his clinical condition improved markedly. He accidentally inhaled the drug again, and the coughing and fever began again. The drug lymphocyte stimulation test was positive only for the fibrinolysin-deoxyribonuclease mixture. Based on these findings, we diagnosed pneumonitis induced by this fibrinolysin-deoxyribonuclease mixture. To our knowledge, this is the first reported case of pneumonitis caused by this fibrinolysin-doxyribonuclease mixture.

[Erythroleukemia in pregnancy with successful outcome of delivery]

A 37-year-old woman was admitted to our hospital because of anemia in the 33rd week of pregnancy. On admission, the hemoglobin was 7.6 g/dl, platelets 508,000/microliters and WBC 8,300/microliters with 4% blast cells. Bone marrow aspirate demonstrated 50% erythroblasts of nucleated cells, which had prominent megaloid and polynucleic changes, and 20% myeloblast cells. We diagnosed her as having erythroleukemia. Receiving packed-red-cell transfusions, she had a cesarean section, and gave birth to a female infant (BW 2,175 g) in the 34th week of pregnancy. At the same time, she had a total hysterectomy with left adnexectomy. The postoperative course was favorable. She had a combination chemotherapy of BHAC-DMP, resulting in a partial remission. After the second induction chemotherapy with subcutaneous use of G-CSF and BHAC-DMP, complete remission was obtained, which lasted for almost 17 months. The child is growing well without any hematological disorder.

Diagnostic reliability of simultaneous measurements of beta human chorionic gonadotropin and pregnancy-specific beta-1-glycoprotein in serum of patients with trophoblastic disease

Serum levels for beta-human chorionic gonadotropin (beta-hCG) and pregnancy-specific beta 1-glycoprotein (SP1) in patients with trophoblastic disease were measured by radioimmunoassay and enzyme-linked immunosorbent assay. The beta-hCG:SP1 ratios were below 1.0 in all 22 cases of complete hydatidiform mole and in 8 of 9 cases of partial hydatidiform mole. Two (10.5%) of 19 cases of invasive mole involving metastasis had ratios that rose above 1.0 during chemotherapy. Ratios ranged from 1.6 to 29 in 11 of 15 cases of choriocarcinoma before chemotherapy. The remaining 4 cases, diagnosed within 3 months of antecedent pregnancy, had ratios below 0.99. Thus, the difference between choriocarcinoma and nonchoriocarcinoma beta-hCG:SP1 ratios may be due to trophoblastic differentiation based on the developmental stage and with trophoblast age, or due to the mass and potential activity of trophoblastic cells.

Serum concentration of placental proteins (PP5 and PP10) in toxemia of pregnancy as related to intrauterine growth retardation

Maternal serum concentrations of placental proteins 5 (PP5) and 10 (PP10) were measured by radioimmunoassay in 568 samples obtained from 308 healthy pregnant women and 63 women having toxemia of pregnancy. Below-normal PP5 values were more widely distributed in the mild than in the severe toxemia group, while the incidence of above-normal PP5 values was found only in the severe toxemia group. The incidence of below-normal PP10 values was higher in the severe than in the mild toxemia group. Our study thus suggests that simultaneous measurement of PP5 and PP10 concentrations in maternal serum in toxemia of pregnancy is a useful monitoring technique for predicting progressive pathological change and placental dysfunction related to IUGR.