ECONOMIC AND BEHAVIORAL FACTORS IN AN INDIVIDUALfS DECISION TO TAKE THE INFLUENZA VACCINATION IN JAPAN

In this paper, we investigate what people in Japan consider when deciding to take the influenza vaccination. We develop an economic model to explain the mechanism by which people decide to take the influenza vaccination. Using our model and the data obtained from a large-scale survey we conducted in Japan, we demonstrated that people make rational decisions about vaccinations after considering its cost and benefits. People consider the probability of infection, severity of the disease, and the vaccinationfs effectiveness and side effects. The time discount rate is another consideration because the timing of costs and benefits of the vaccination differ. Risk aversion (fearing the contraction of the flu and vaccinationfs side effects) also affects the decision. People also deviate from rationality-altruism and status quo bias play important roles in the decision-making. Overconfidence indirectly affects the decision via perception variables such as the subjective probability of infection and assessment of influenzafs severity. The decision also depends on attributes such as gender, age, and marital status. If the general perception of flu and vaccination is inaccurate, supplying accurate information regarding those may increase or decrease the vaccination rate, depending on whether this perception is, respectively, higher or lower than the objective rates. Thus, we examine whether the general perception is biased. Our survey suggests that disseminating information on the vaccinationfs effectiveness may increase the rate of vaccination, whereas that on the probability of infection may have the opposite effect.influenza; inoculation; survey; time preference; Japan

Cre-loxP-controlled cell-cycle checkpoint engineering in Chinese Hamster ovary cells

The gene amplification system is widely used in Chinese hamster ovary (CHO) cells for the productive cell line construction of therapeutic proteins. To enhance the efficiency of conventional gene amplification systems, we previously presented a novel method using cell-cycle checkpoint engineering1). Here, we constructed high-producing and stable cells by the conditional expression of mutant cell division cycle 25 homolog B (CDC25B) using the Cre-loxP system2). A bispecific antibody-producing CHO DG44-derived cell line was transfected with floxed mutant CDC25B. After inducing gene amplification in the presence of 250 nM methotrexate, mutant CDC25B sequence was removed by Cre recombinase protein expression. Overexpression of the floxed mutant CDC25B significantly enhanced the efficiency of transgene amplification and productivity. Moreover, the specific production rate of the isolated clone CHO Cre-1 and Cre-2 were approximately 11-fold and 15-fold higher than that of mock-transfected clone CHO Mock-S. Chromosomal aneuploidy was increased by mutant CDC25B overexpression, but Cre-1 and Cre-2 did not show any changes in chromosome number during long-term cultivation, as is the case with CHO Mock-S. Our results suggest that high-producing and stable cells can be constructed by conditionally controlling a cell-cycle checkpoint integrated in conventional gene amplification systems