Vaccine-induced protection against SARS-CoV-2 requires IFN-γ-driven cellular immune response.

The overall success of worldwide mass vaccination in limiting the negative effect of the COVID-19 pandemics is inevitable, however, recent SARS-CoV-2 variants of concern, especially Omicron and its sub-lineages, efficiently evade humoral immunity mounted upon vaccination or previous infection. Thus, it is an important question whether these variants, or vaccines against them, induce anti-viral cellular immunity. Here we show that the mRNA vaccine BNT162b2 induces robust protective immunity in K18-hACE2 transgenic B-cell deficient (µMT) mice. We further demonstrate that the protection is attributed to cellular immunity depending on robust IFN-γ production. Viral challenge with SARS-CoV-2 Omicron BA.1 and BA.5.2 sub-variants induce boosted cellular responses in vaccinated µMT mice, which highlights the significance of cellular immunity against the ever-emerging SARS-CoV-2 variants evading antibody-mediated immunity. Our work, by providing evidence that BNT162b2 can induce significant protective immunity in mice that are unable to produce antibodies, thus highlights the importance of cellular immunity in the protection against SARS-CoV-2.

Research on heterogeneous customer hotel supply chain channel selection model based on game theory

In the context of the epidemic of New Coronavirus, customers have a heterogeneous preference for hotel consumption channels. Based on this, the hotel supply chain channel selection model was established, and the wholesale of hotels and online travel agencies (OTA) under the single-channel and dual-channel structures was analyzed. The optimal pricing under the cooperation mode with the agent provides a basis for the hotel’s channel and business model selection decision. On the basis of theoretical derivation, the use of Ctrip data to conduct numerical analysis and research found that: the choice of hotel channel structure and cooperation mode is affected by a variety of factors;when the hotel service capacity is low, the hotel will not cooperate with OTA, only Implement single-channel sales through direct sales channels;conversely, hotels will tend to cooperate with OTAs to implement dual-channel sales;when online shopping customers have a higher level of acceptance of online channels and a higher proportion or a lower commission rate, the agency model is better than wholesale Mode;otherwise, the wholesale mode is most beneficial to the hotel.The analysis shows that when the hotel service capacity is lower, the hotel only conducts direct sales through a single channel;otherwise, the hotel will tend to cooperate with OTA to sell as many rooms as possible through dual channels.