Long-Term immunopersistence and safety of the Escherichia coli-produced HPV-16/18 bivalent vaccine in Chinese adolescent girls.

The study assessed long-term immunopersistence and safety of the Escherichia coli (E. coli)-produced HPV-16/18 bivalent vaccine. In total, 979 participants in the initial immunogenicity noninferiority study, including girls aged 9-14 years who were randomized in a 1:1 ratio to receive 2 doses at months 0 and 6 (n = 301) or 3 doses at months 0, 1 and 6 (n = 304); girls aged 15-17 years (n = 149) and women aged 18-26 years (n = 225) who received 3 doses of the vaccine, were invited to participate in follow-up to 30 months post vaccination (NCT03206255). Serum samples were collected at months 18 and 30, and anti-HPV-16/18 IgG antibodies were measured by enzyme-linked immunosorbent assay. Serious adverse events (SAEs) occurred from month 7 through month 30 were recorded. At month 30, in the per-protocol set, all participants remained seropositive, except for one girl in the 9-14 years (2 doses) group who seroconverted to negative for HPV-18. HPV-16 and HPV-18 antibody levels were higher in girls aged 9-17 years who received 3 doses (125.3 and 60.2 IU/ml) than in women aged 18-26 years who received 3 doses (72.6 and 28.3 IU/ml), and those in girls aged 9-14 years who received 2 doses (73.2 and 24.9 IU/ml) were comparable to those in women aged 18-26 years who received 3 doses. No SAEs were reported to be causally related to vaccination. The E. coli-produced bivalent HPV-16/18 vaccine is safe and induces persistent protective antibodies for up to 30 months after vaccination in girls aged 9-17 years receiving 2 or 3 doses.

Zinc alleviates the heat stress of primary cultured hepatocytes of broiler embryos via enhancing the antioxidant ability and attenuating the heat shock responses.

Zinc (Zn) has been shown to attenuate the adverse effects of heat stress on broilers, but the mechanisms involving this process remain unclear. We aimed to investigate possible protective mechanisms of Zn on primary cultured hepatocytes of broiler embryos subjected to heat stress. Three experiments were conducted. In Exp. 1, hepatocytes were treated with 0, 50, 100, 200, or 400 µmol/L added Zn as inorganic Zn sulfate (iZn) for 12, 24 or 48 h. In Exp. 2, cells were exposed to 40 °C (a normal temperature [NT]) and 44 °C (a high temperature [HT]) for 1, 2, 4, 6, or 8 h. In Exp. 3, cells were preincubated with 0 or 50 µmol/L Zn as iZn or organic Zn lysine chelate (oZn) for 8 h under NT, and then incubated with the same Zn treatments under NT or HT for 4 or 6 h. The biomarkers of antioxidative status and heat stress in cells were measured. The results in Exp. 1 indicated that 50 µmol/L Zn and 12 h incubation were the optimal conditions for increasing antioxidant ability of hepatocytes. In Exp. 2, the 4 or 6 h incubation under HT was effective in inducing heat shock responses of hepatocytes. In Exp. 3, HT elevated (P < 0.01) malondialdehyde content and expressions of heat shock protein 70 (HSP70) mRNA and protein, as well as HSP90 mRNA. However, Zn supplementation increased (P < 0.05) copper zinc superoxide dismutase (CuZnSOD) activity and metallothionein mRNA expression, and effectively decreased (P < 0.05) the expressions of HSP70 mRNA and protein, as well as HSP90 mRNA. Furthermore, oZn was more effective (P < 0.05) than iZn in enhancing CuZnSOD activity of hepatocytes under HT. It was concluded that Zn (especially oZn) could alleviate heat stress of broiler hepatocytes via enhancing their antioxidant ability and attenuating heat shock responses.

Immunogenicity noninferiority study of 2 doses and 3 doses of an Escherichia coli-produced HPV bivalent vaccine in girls vs. 3 doses in young women.

A new HPV-16/18 bivalent vaccine expressed by the Escherichia coli has been proven to be efficacious in adult women. A randomized, immunogenicity noninferiority study of this candidate vaccine was conducted in December 2015 in China. Girls aged 9-14 years were randomized to receive 2 doses at months 0 and 6 (n=301) or 3 doses at months 0, 1 and 6 (n=304). Girls aged 15-17 years (n=149) and women aged 18-26 years (n=225) received 3 doses. The objectives included noninferiority analysis of the IgG geometric mean concentration (GMC) ratio (95% CI, lower bound>0.5) to HPV-16 and HPV-18 at month 7 in girls compared with women. In the per-protocol set, the GMC ratio of IgG was noninferior for girls aged 9-17 years receiving 3 doses compared with women (1.76 (95% CI, 1.56, 1.99) for HPV-16 and 1.93 (95% CI, 1.69, 2.21) for HPV-18) and noninferior for girls aged 9-14 years receiving 2 doses compared with women (1.45 (95% CI, 1.25, 1.62) for HPV-16 and 1.17 (95% CI, 1.02, 1.33) for HPV-18). Noninferiority was also demonstrated for neutralizing antibodies. The immunogenicity of the HPV vaccine in girls receiving 3 or 2 doses was noninferior compared with that in young adult women.