Ad5-nCoV booster and Omicron variant breakthrough infection following two doses of inactivated vaccine elicit comparable antibody levels against Omicron variants.

Little information is available for antibody levels against SARS-CoV-2 variants of concern induced by Omicron breakthrough infection and a third booster with an inactivated vaccine (InV) or Ad5-nCoV in people with completion of two InV doses. Plasma was collected from InV pre-vaccinated Omicron-infected patients (OIPs), unvaccinated OIPs between 0 and 22 days, and healthy donors (HDs) 14 days or 6 months after the second doses of an InV and 14 days after a homogenous booster or heterologous booster of Ad5-nCoV. Anti-Wuhan-, Anti-Delta-, and Anti-Omicron-receptor binding domain (RBD)-IgG titers were detected using enzyme-linked immunosorbent assay. InV pre-vaccinated OIPs had higher anti-Wuhan-, anti-Delta-, and anti-Omicron-RBD-IgG titers compared to unvaccinated OIPs. Anti-Wuhan-RBD-IgG titers sharply increased in InV pre-vaccinated OIPs 0-5 days postinfection (DPI), while the geometric mean titers (GMTs) of anti-Delta- and anti-Omicron-RBD-IgG were 3.3-fold and 12.0-fold lower. Then, the GMT of anti-Delta- and anti-Omicron-RBD-IgG increased to 35 112 and 28 186 during 11-22 DPI, about 2.6-fold and 3.2-fold lower, respectively, than the anti-Wuhan-RBD-IgG titer. The anti-Wuhan-, anti-Delta-, and anti-Omicron-RBD-IgG titers declined over time in HDs after two doses of an InV, with 25.2-fold, 5.6-fold, and 4.5-fold declination, respectively, at 6 months relative to the titers at 14 days after the second vaccination. Anti-Wuhan-, anti-Delta-, and anti-Omicron-RBD-IgG titers elicited by a heterologous Ad5-nCoV booster were significantly higher than those elicited by an InV booster, comparable to those in InV pre-vaccinated OIPs. InV and Ad5-nCoV boosters could improve humoral immunity against Omicron variants. Of these, the Ad5-nCoV booster is a better alternative.

Omicron variants breakthrough infection elicited higher specific memory immunity than third dose booster in healthy vaccinees.

Homologous booster, heterologous booster, and Omicron variants breakthrough infection (OBI) could improve the humoral immunity against Omicron variants. Questions concerning about memory B cells (MBCs) and T cells immunity against Omicron variants, features of long-term immunity, after booster and OBI, needs to be explored. Here, comparative analysis demonstrate antibody and T cell immunity against ancestral strain, Delta and Omicron variants in Omicron breakthrough infected patients (OBIPs) are comparable to that in Ad5-nCoV boosted healthy volunteers (HVs), higher than that in inactivated vaccine (InV) boosted HVs. However, memory B cells (MBCs) immunity against Omicron variants was highest in OBIPs, followed by Ad5-nCoV boosted and InV boosted HVs. OBIPs and Ad5-nCoV boosted HVs have higher classical MBCs and activated MBCs, and lower naïve MBCs and atypical MBCs relative to both vaccine boosted HVs. Collectively, these data indicate Omicron breakthrough infection elicit higher MBCs and T cells against SARS-CoV-2 especially Omicron variants relative to homologous InV booster and heterologous Ad5-nCoV booster.

Effects of hyperbaric oxygen treatment on gastric cancer cell line SGC7901.

Hyperbaric oxygen (HBO) has been previously identified as an effective adjunct treatment option for the management of brain injury, diabetic ulcers and chronic wounds. However, the roles of HBO as an adjunctive therapy for tumors remain controversial. The present research project was performed to explore the effects of HBO treatment on proliferation, autophagy and endoplasmic reticulum stress response of the gastric cancer cell line, SGC7901. The present study demonstrated that, after subjecting SGC7901 cells to HBO treatment, the increase in cell proliferation was significant, compared with that of the control group. In addition, there was a significant increase in LC3-phosphatidylethanolamine conjugate (LC3-II) level, as well as binding immunoglobulin protein level, and a significant decrease in CCAAT-enhancer-binding protein homologous protein level. These suggested that hyperbaric oxygen treatment alone may promote proliferation and cell survival of gastric cancer cell SGC7901, and inhibit apoptosis through regulating cell autophagy and oxidative stress.