Immune escape and waning immunity of COVID-19 monovalent mRNA vaccines against symptomatic infection with BA.1/BA.2 and BA.5 in Japan

BACKGROUND

Repeated emergence of variants with immune escape capacity and waning immunity from vaccination are major concerns for COVID-19. We examined whether the surge in Omicron subvariant BA.5 cases was due to immune escape or waning immunity through vaccine effectiveness (VE) evaluation.

METHODS

A test-negative case-control study was conducted in 16 clinics/hospitals during the BA.1/BA.2-dominant and BA.5-dominant periods. VE against symptomatic infection was estimated after adjusting for age, sex, comorbidity, occupation, testing frequency, prior infection, close contact history, clinic/hospital, week, and preventive measures. Absolute VE (aVE) was calculated for 2/3/4 doses, compared to the unvaccinated. Relative VE (rVE) was calculated, comparing 3 vs 2 and 4 vs 3 doses.

RESULTS

13,025 individuals were tested during the BA.1/BA.2-dominant and BA.5-dominant periods with similar baseline characteristics. For BA.1/BA.2, aVE was 52 % (95 %CI:34-66) 14 days-3 months post-dose 2, 42 % (29-52) > 6 months post-dose 2, 71 % (64-77) 14 days-3 months post-dose 3, and 68 % (52-79) 3-6 months post-dose 3. rVE was 49 % (38-57) 14 days-3 months post-dose 3 and 45 % (18-63) 3-6 months post-dose 3. For BA.5, aVE was 56 % (27-73) 3-6 months post-dose 2, 32 % (12-47) > 6 months post-dose 2, 70 % (61-78) 14 days-3 months post-dose 3, 59 % (48-68) 3-6 months post-dose 3, 50 % (29-64) > 6 months post-dose 3, and 74 % (61-83) ≥ 14 days post-dose 4. rVE was 56 % (45-65) 14 days-3 months post-dose 3, 39 % (27-48) 3-6 months post-dose 3, 25 % (-2-45) > 6 months post-dose 3, and 30 % (-6-54) ≥ 14 days post-dose 4.

CONCLUSIONS

Booster doses initially provided high protection against BA.5 at a level similar to that against BA.1/BA.2. However, the protection seemed shorter-lasting against BA.5, which likely contributed to the surge. Furthermore, rVE post-dose 4 was low even among recent vaccinees. These results support the introduction of variant-containing vaccines and emphasize the need for vaccines with longer duration of protection.

Effectiveness of BA.1- and BA.4/BA. 5-Containing Bivalent COVID-19 mRNA Vaccines Against Symptomatic SARS-CoV-2 Infection During the BA.5-Dominant Period in Japan

In this multicenter, prospective, test-negative, case-control study in Japan, the effectiveness of both BA.1-containing and BA.4/BA.5-containing bivalent coronavirus disease 2019 mRNA vaccines against symptomatic infection during the BA.5-dominant period was high compared with no vaccination (65% and 76%) and moderate compared with monovalent vaccines administered over half a year earlier (46% combined).

Coronavirus Disease 19 (COVID-19) Vaccine Effectiveness Against Symptomatic Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infection During Delta-Dominant and Omicron-Dominant Periods in Japan: A Multicenter Prospective Case-control Study (Factors Associated with SARS-CoV-2 Infection and the Effectiveness of COVID-19 Vaccines Study)

BACKGROUND

Although several coronavirus disease 2019 (COVID-19) vaccines initially showed high efficacy, there have been concerns because of waning immunity and the emergence of variants with immune escape capacity.

METHODS

A test-negative design case-control study was conducted in 16 healthcare facilities in Japan during the Delta-dominant period (August-September 2021) and the Omicron-dominant period (January-March 2022). Vaccine effectiveness (VE) against symptomatic severe acute respiratory syndrome coronavirus 2 infection was calculated for 2 doses for the Delta-dominant period and 2 or 3 doses for the Omicron-dominant period compared with unvaccinated individuals.

RESULTS

The analysis included 5795 individuals with 2595 (44.8%) cases. Among vaccinees, 2242 (55.8%) received BNT162b2 and 1624 (40.4%) received messenger RNA (mRNA)-1273 at manufacturer-recommended intervals. During the Delta-dominant period, VE was 88% (95% confidence interval [CI], 82-93) 14 days to 3 months after dose 2 and 87% (95% CI, 38-97) 3 to 6 months after dose 2. During the Omicron-dominant period, VE was 56% (95% CI, 37-70) 14 days to 3 months since dose 2, 52% (95% CI, 40-62) 3 to 6 months after dose 2, 49% (95% CI, 34-61) 6+ months after dose 2, and 74% (95% CI, 62-83) 14+ days after dose 3. Restricting to individuals at high risk of severe COVID-19 and additional adjustment for preventive measures (ie, mask wearing/high-risk behaviors) yielded similar estimates, respectively.

CONCLUSIONS

In Japan, where most are infection-naïve, and strict prevention measures are maintained regardless of vaccination status, 2-dose mRNA vaccines provided high protection against symptomatic infection during the Delta-dominant period and moderate protection during the Omicron-dominant period. Among individuals who received an mRNA booster dose, VE recovered to a high level.

Evaluation of a Tool that Enables Cancer Patients to Participate in the Decision-Making Process during Treatment Selection

BACKGROUND

Patient participation in decisions related to their treatment is strongly recommended. This study was conducted to develop and evaluate a support tool that can help patients make decisions related to their own treatment.

METHODS

Twenty cancer patients who were hospitalized for first-line treatment were enrolled. Before hospitalization, a 'Check sheet on treatment selection', which contained 14 questions, was distributed to patients and/or their families. After hospitalization, the attending physician explained the treatment while referring to the written check sheet. At discharge, patients' responses to the 'Questionnaire on check sheet and treatment selection' were collected to evaluate the utility of the check sheet. Finally, the 'Questionnaire of the check sheet' was handed to the attending physician to evaluate.

RESULTS

Of the fourteen patients who responded to the questionnaire, all indicated that the check sheets were helpful for decision-making and that using the sheets empowered them to ask their doctors questions. Only one person felt uncomfortable with compiling the check sheet. Physicians stated that the check sheet facilitated patient decision-making and improved communication with patients. However, some felt that this activity increased the administrative burden of medical professionals.

CONCLUSION

Almost all patients stated that the present check sheet was useful as a decision support tool and facilitated communication between doctors and patients. Before incorporation into general clinical practice, this increased benefit should be weighed against the potential extra administrative workload imposed on clinicians.

Effective Crizotinib schedule for an elderly patient with ALK rearranged non-small-cell lung cancer: a case report

Background

Non-small-cell lung cancers (NSCLCs) harboring translocations in anaplastic lymphoma kinase (ALK) are highly sensitive to small-molecule ALK kinase inhibitors, such as crizotinib.

Case presentation

We describe a case of post-operative local recurrence of lung adenocarcinoma in an 81 year-old male. He underwent radiation and received chemotherapy with docetaxel, but neither treatment regimen was effective. Following identification of ALK rearrangements, crizotinib treatment was initiated. After treatment with crizotinib for 5 days, adverse events including acute renal failure (grade 2/CTCAE ver4.0) and congestive heart failure (grade 3) occurred. Crizotinib modified treatment was required. Half dose of crizotinib treatment could not control tumor progression. Ultimately, crizotinib was administrated at a dose of 250 mg twice daily every 3 day dosing for 13 months with maintenance of the anti-tumor effect.

Conclusion

This is the first case report that skip schedule was more effective than dose reduction daily in crizotinib administration for ALK rearranged NSCLC patient with severe adverse events.

Acute Lung Injury Accompanying Alveolar Hemorrhage Associated with Flu Vaccination in the Elderly

Flu vaccinations are administered worldwide every winter for prevention. We herein describe a case of acute lung injury resulting from a pathologically confirmed alveolar hemorrhage, which may have been closely related to a preceding vaccination for pandemic influenza A of 2009/10. The present patient had been hospitalized with an acute lung injury after flu vaccination one year prior to the present hospitalization, however, he received another flu vaccination. We should consider a vaccine-related adverse reaction as a potential cause of pulmonary disease if patients present with this illness during the winter season.

An effective method for isolating alginate lyase-producing Bacillus sp. ATB-1015 strain and purification and characterization of the lyase

A new alginate lyase-producing micro-organism, designated as Bacillus sp. strain ATB-1015, was effectively isolated from soil samples pretreated for 3 months with a substrate of the enzyme, sodium alginate. Alginate lyase activity was assayed by the degrading activity of biofilm of Teflon sheet discs, which was formed by a mucoid strain of Pseudomonas aeruginosa PAM3 selected from clinical isolates. The extracellular alginate lyase was precipitated with ammonium sulphate from the culture broth, and purified by gel filtration and anion exchange chromatography. The molecular weight of the lyase was estimated to be 41 kDa by SDS polyacrylamide gel electrophoresis and Sephacryl S-200 HR column chromatography. The optimum pH and temperature for the enzyme activity were around 7.5 and 37 degrees C, respectively, and the Km value was 0.17% with the substrate, sodium alginate. The lyase activity was completely inhibited by treatment with 1 mmol l-1 of EDTA and the decreased activity was almost completely recovered by the addition of 2 mmol l-1 of CaCl2. The activity was not affected by treatment with the protein denaturants, 0.01 mol l-1 of SDS or 1 mmol l-1 of urea. The lyase had substrate specificity for both the poly-guluronate and poly-mannuronate units in the alginate molecule.