1. Abente, E. J., Gauger, P. C., Walia, R. R., Rajao, D. S., Zhang, J., Harmon, K. M., Killian, M. L. and Vincent, A. L. Detection and characterization of an H4N6 avian- lineage influenza A virus in pigs in the Midwestern United States. Virology. 511, 56–65, 2017.
2. Ashton, J. C. ANOVA and the analysis of drug combination experiments. Nat. Methods. 12, 1108, 2015.
3. Bailey, E., Long, L., Zhao, N., Hall, J. S., Baroch, J. A., Senter, L., Cunningham, F. L., Pharr, G. T., Hanson, L., Deliberto, T. J. and Wan, X. Antigenic characterization of H3 subtypes of avian influenza A viruses from North America. Avian Dis. 60, 346–353, 2016.
4. Beigelman, A., Castro, M., Schweiger, T. L., Wilson, B. S., Zheng, J., Yin-declue, H., Sajol, G., Giri, T., Sierra, O. L., Isaacson-schmid, M., Sumino, K., Schechtman, K. B. and Bacharier, L. B. Vitamin D levels are unrelated to the severity of respiratory syncytial virus bronchiolitis among hospitalized infants. J. Pediatric Infect. Dis. Soc. 4, 182–188, 2015.
5. Biondi, P., Pepe, J., Biamonte, F., Occhiuto, M., Parisi, M., Demofonti, C., Baffa, V., Minisola, S. and Cipriani, C. Oral calcidiol is a good form of vitamin D supplementation. Clin. Cases Miner. Bone Metab. 14, 207–208, 2017.
6. Cannell, J. J., Vieth, R., Umhau, J. C., Holick, M. F., Grant, W. B., Madronich, S., Garland, C. F. and Giovannucci, E. Epidemic influenza and vitamin D. Epidemiol. Infect. 134, 1129–1140, 2006.
7. Cannell, J. J., Zasloff, M., Garland, C. F., Scragg, R. and Giovannucci, E. On the epidemiology of influenza. Virol. J. 5, 1–12, 2008.
8. Castetbon, K., Vernay, M., Malon, A., Salanave, B., Deschamps, V., Roudier, C., Oleko, A., Szego, E. and Hercberg, S. Dietary intake, physical activity and nutritional status in adults: The French nutrition and health survey (ENNS, 2006- 2007). Br. J. Nutr. 102, 733–743, 2009.
9. Chan, R. W. Y., Leung, C. Y. H., Nicholls, J. M., Peiris, J. S. M. and Chan, M. C. W. Proinflammatory cytokine response and viral replication in mouse bone marrow derived macrophages infected with influenza H1N1 and H5N1 viruses. PLoS One. 7, 1–8, 2012.
10. Chang, J. H., Cha, H. R., Lee, D. S., Seo, K. Y. and Kweon, M. N. 1,25-dihydroxyvitamin D3 inhibits the differentiation and migration of TH17 cells to protect against experimental autoimmune encephalomyelitis. PLoS One. 5, 1–12, 2010.
11. Chen, S., Liu, G., Chen, J., Hu, A., Zhang, L., Sun, W., Tang, W., Liu, C., Zhang, H., Ke, C., Wu, J. and Chen, X. Ponatinib protects mice from lethal influenza infection by suppressing cytokine storm. Front. Immunol. 10, 1–13, 2019.
12. Chu, D. H., Sakoda, Y., Nishi, T., Hiono, T., Shichinohe, S., Okamatsu, M. and Kida, H. Potency of an inactivated influenza vaccine prepared from A/duck/Mongolia/119/2008 (H7N9) against the challenge with A/Anhui/1/2013 (H7N9). Vaccine. 32, 3473–3479, 2014.
13. Couceiro, J. N. S. S., Paulson, J. C. and Baum, L. G. Influenza virus strains selectively recognize sialyloligosaccharides on human respiratory epithelium. Virus Res. 29, 155–165, 1993.
14. Coussens, A. K., Wilkinson, R. J., Hanifa, Y., Nikolayevskyy, V., Elkington, P. T., Islam, K., Timms, P. M., Venton, T. R., Bothamley, G. H., Packe, G. E., Darmalingam, M., Davidson, R. N., Milburn, H. J., Baker, L. V., Barker, R. D., Mein, C. A., Bhaw-Rosun, L., Nuamah, R., Young, D. B., Drobniewski, F. A., Griffiths, C. J. and Martineau, A. R. Vitamin D accelerates resolution of inflammatory responses during tuberculosis treatment. Proc. Natl. Acad. Sci. U. S. A. 109, 15449–15454, 2012.
15. Cynthia, A. Vitamin D and the immune system. J. Investig. Med. 59, 881–886, 2011.
16. Deluca, H. F., Prahl, J. M. and Plum, L. A. 1,25-Dihydroxyvitamin D is not responsible for toxicity caused by vitamin D or 25-hydroxyvitamin D. Arch. Biochem. Biophys. 505, 226–230, 2011.
17. European Food Safe Authority, (EFSA). Scientific opinion on the tolerable upper intake level of vitamin D. avaiable online: https://efsa.onlinelibrary.wiley.com/doi/pdf/10.2903/j.efsa.2012.2813 (accessed on Apr 12, 2020).
18. Goncalves-Mendes, N., Talvas, J., Dualé, C., Guttmann, A., Corbin, V., Marceau, G., Sapin, V., Brachet, P., Evrard, B., Laurichesse, H. and Vasson, M. P. Impact of vitamin D supplementation on influenza vaccine response and immune functions in deficient elderly persons: A randomized placebo-controlled trial. Front. Immunol. 10, 65, 2019.
19. Grant, W. B. and Giovannucci, E. The possible roles of solar ultraviolet-B radiation and vitamin D in reducing case-fatality rates from the 1918–1919 influenza pandemic in the United States. Dermatoendocrinol. 1, 215–219, 2009.
20. Grant, W. B., Lahore, H., McDonnell, S. L., Baggerly, C. A., French, C. B., Aliano, J. L. and Bhattoa, H. P. Evidence that vitamin D supplementation could reduce risk of influenza and COVID-19 infections and deaths. Nutrients. 12, 988, 2020.
21. Greenberg., M. E., Michael H. Lai, B., Hartel., G. F., Wichems., C. H., Gittleson., C., Bennet., J., Dawson., G., Hu., W., Leggio., C., Washington., D. and Basser., R. L. Response to a monovalent 2009 Influenza A (H1N1) vaccine. N. Engl. J. Med. 687–696, 2015.
22. Gruber-Bzura, B. M. Vitamin D and influenza—Prevention or therapy? Int. J. Mol. Sci. 19, 2018.
23. Gui, B., Chen, Q., Hu, C., Zhu, C. and He, G. Effects of calcitriol (1,25-dihydroxy- vitamin D3) on the inflammatory response induced by H9N2 influenza virus infection in human lung A549 epithelial cells and in mice. Virol. J. 14, 1–11, 2017.
24. Heaney, R. P., Davies, K. M., Chen, T. C., Holick, M. F. and Janet Barger-Lux, M. Human serum 25-hydroxycholecalciferol response to extended oral dosing with cholecalciferol. Am. J. Clin. Nutr. 77, 204–210, 2003.
25. Hiono, T., Okamatsu, M., Yamamoto, N., Ogasawara, K., Endo, M., Kuribayashi, S., Shichinohe, S., Motohashi, Y., Chu, D. H., Suzuki, M., Ichikawa, T., Nishi, T., Abe, Y., Matsuno, K., Tanaka, K., Tanigawa, T., Kida, H. and Sakoda, Y. Experimental infection of highly and low pathogenic avian influenza viruses to chickens, ducks, tree sparrows, jungle crows, and black rats for the evaluation of their roles in virus transmission. Vet. Microbiol. 182, 108–115, 2016.
26. Holick, M. F. Vitamin D deficiency. N. Engl. J. Med. 357, 266–281, 2007.
27. Hovden, A. O., Cox, R. J. and Haaheim, L. R. Whole influenza virus vaccine is more immunogenic than split influenza virus vaccine and induces primarily an IgG2a response in BALB/c mice. Scand. J. Immunol. 62, 36–44, 2005.
28. Hu, Y., Liu, X., Li, S., Guo, X., Yang, Y. and Jin, M. Complete genome sequence of a novel H4N1 influenza virus isolated from a pig in central China. J. Virol. 86, 13879–13879, 2012.
29. Huang, F., Zhang, C., Liu, Q., Zhao, Y., Zhang, Y., Qin, Y., Li, X., Li, C., Zhou, C., Jin, N. and Jiang, C. Identification of amitriptyline HCl, flavin adenine dinucleotide, azacitidine and calcitriol as repurposing drugs for influenza A H5N1 virus-induced lung injury. PLoS Pathog. 16, 1–16, 2020.
30. Ivanov, A. P., Dragunsky, E. M. and Chumakov, K. M. 1,25‐dihydroxyvitamin D3 enhances systemic and mucosal immune responses to inactivated poliovirus vaccine in mice. J. Infect. Dis. 193, 598–600, 2006.
31. Iyer, S. S. and Cheng, G. Role of interleukin 10 transcriptional regulation in inflammation and autoimmune disease. Crit. Rev. Immunol. 32, 23–63, 2012.
32. Karasin, A. I., Brown, I. H., Carman, S. and Olsen, C. W. Isolation and characterization of H4N6 avian influenza viruses from pigs with pneumonia in Canada. J. Virol. 74, 9322–9327, 2000.
33. Keating, P., Munim, A. and Hartmann, J. X. Effect of vitamin D on T-helper type 9 polarized human memory cells in chronic persistent asthma. Ann. Allergy Asthma Immunol. 112, 154–162, 2014.
34. Kida, H., Brown, L. E. and Webster, R. G. Biological activity of monoclonal antibodies to operationally defined antigenic regions on the hemagglutinin molecule of A/seal/Massachusetts/1/80 (H7N7) influenza virus. Virology. 122, 38–47, 1982.
35. Kida, H. K. Ecology of Influenza Viruses in Nature , Birds , and Humans. Glob. Environ. Res. 12, 9–14, 2008.
36. Kida, H., Kawaoka, Y., Naeve, C. W. and Webster, R. G. Antigenic and genetic conservation of H3 influenza virus in wild ducks. Virology. 159, 109–119, 1987.
37. Li, W., Dong, H., Zhao, H., Song, J., Tang, H., Yao, L., Liu, L., Tong, W., Zou, M., Zou, F. and Cai, S. 1,25-dihydroxyvitamin D3 prevents toluene diisocyanate- induced airway epithelial barrier disruption. Int. J. Mol. Med. 36, 263–270, 2015.
38. Liang, L., Deng, G., Shi, J., Wang, S., Zhang, Q., Kong, H., Gu, C. and Guan, Y. Transmission of H4 avian influenza viruses isolated from live poultry markets in China. J. Virol. 90, 1455–1469, 2016.
39. Lin, R. Crosstalk between Vitamin D metabolism, VDR signalling, and innate immunity. Biomed. Res. Int. 2016, 1–5, 2016.
40. Long, J. S., Mistry, B., Haslam, S. M. and Barclay, W. S. Host and viral determinants of influenza A virus species specificity. Nat. Rev. Microbiol. 17, 67– 81, 2019.
41. Loubet, P., Enouf, V. and Launay, O. The risk of a swine influenza pandemic: still a concern? Expert Rev. Respir. Med. 13, 803–805, 2019.
42. Mallya, S. M., Corrado, K. R., Saria, E. A., Yuan, F. ning F., Tran, H. Q., Saucier, K., Atti, E., Tetradis, S. and Arnold, A. Modeling vitamin D insufficiency and moderate deficiency in adult mice via dietary cholecalciferol restriction. Endocr. Res. 41, 290–299, 2016.
43. Marcinowska-Suchowierska, E., Kupisz-Urbanska, M., Lukaszkiewicz, J., Pludowski, P. and Jones, G. Vitamin D toxicity-A clinical perspective. Front. Endocrinol. (Lausanne). 9, 1–7, 2018.
44. Maria E. Sundaram and Coleman, L. A. Vitamin D and influenza. Adv. Nutr. 3, 517–525, 2012.
45. Medina, R. A. and García-Sastre, A. Influenza A viruses: New research developments. Nat. Rev. Microbiol. 9, 590–603, 2011.
46. Nagai, T., Makino, S., Ikegami, S., Itoh, H. and Yamada, H. Effects of oral administration of yogurt fermented with Lactobacillus delbrueckii ssp. bulgaricus OLL1073R-1 and its exopolysaccharides against influenza virus infection in mice. Int. Immunopharmacol. 11, 2246–2250, 2011.
47. Nakatsukasa, A., Kuruma, K., Okamatsu, M., Hiono, T., Suzuki, M., Matsuno, K., Kida, H., Oyamada, T. and Sakoda, Y. Potency of whole virus particle and split virion vaccines using dissolving microneedle against challenges of H1N1 and H5N1 influenza viruses in mice. Vaccine. 35, 2855–2861, 2017.
48. Nakayama, M., Shichinohe, S., Itoh, Y., Ishigaki, H., Kitano, M., Arikata, M., Pham, V. L., Ishida, H., Kitagawa, N., Okamatsu, M., Sakoda, Y., Ichikawa, T., Tsuchiya, H., Nakamura, S., Le, Q. M., Ito, M., Kawaoka, Y., Kida, H. and Ogasawara, K. Protection against H5N1 highly pathogenic avian and pandemic (H1N1) 2009 influenza virus infection in cynomolgus monkeys by an inactivated H5N1 whole particle vaccine. PLoS One. 8, e82740, 2013.
49. Nishi, T., Sakoda, Y., Okamatsu, M. and Kida, H. Potency of an inactivated influenza vaccine prepared from A/duck/Hong Kong/960/1980 (H6N2) against a challenge with A/duck/Vietnam/OIE-0033/2012 (H6N2) in mice. Arch. Virol. 159, 2567–2574, 2014.
50. Nishikawa, M., Yasuda, K., Takamatsu, M., Abe, K., Nakagawa, K., Tsugawa, N., Hirota, Y., Tanaka, K., Yamashita, S., Ikushiro, S., Suda, T., Okano, T. and Sakaki, T. Generation of 1,25-dihydroxyvitamin D3 in Cyp27b1 knockout mice by treatment with 25-hydroxyvitamin D3 rescued their rachitic phenotypes. J. Steroid Biochem. Mol. Biol. 185, 71–79, 2019.
51. Nomura, N., Sakoda, Y., Soda, K., Okamatsu, M. and Kida, H. An H9N2 infuenza virus vaccine prepared from a non-pathogenic isolate from a migratory duck confers protective immunity in mice against challenge with an H9N2 virus isolated from a girl in Hong Kong. J. Vet. Med. Sci. 74, 441–447, 2012.
52. Okamatsu, M., Sakoda, Y., Hiono, T., Yamamoto, N. and Kida, H. Potency of a vaccine prepared from A/swine/Hokkaido/2/1981 (H1N1) against A/Narita/1/2009 (H1N1) pandemic influenza virus strain. Virol. J. 10, 1–8, 2013.
53. Patel, N., Penkert, R. R., Jones, B. G., Sealy, R. E., Surman, S. L., Sun, Y., Tang, L., De Beauchamp, J., Webb, A., Richardson, J., Heine, R., Dallas, R. H., Ross, A. C., Webby, R. and Hurwitz, J. L. Baseline serum vitamin A and D levels determine benefit of oral vitamin A&D supplements to humoral immune responses following pediatric influenza vaccination. Viruses. 11, 1–21, 2019.
54. Romero, D. C. and Manson, J. Vitamin D and your heart. Circulation. 132, e391- 392, 2015.
55. Scala, M. C., Sala, M., Pietrantoni, A., Spensiero, A., Di, S., Agamennone, M., Bertamino, A., Novellino, E. and Bifulco, G. Lactoferrin-derived peptides active towards influenza : identification of three potent tetrapeptide inhibitors. Sci. Rep. 1–11, 2017.
56. Shin, D., Yang, W., Peng, J., Sawatsky, B. and Messling, V. V. Avian influenza A virus infects swine airway epithelial cells without prior adaptation. Viruses. 12, 1– 16, 2020.
57. Shiva Borji, M. R.-K. Vitamin D and its importance on public health. J. Parathyr. Dis. 4, 20–24, 2015.
58. Smith, D. J., Lapedes, A. S., Jong, J. C. de, Bestebroer, T. M., Rimmelzwaan, G. F., Osterhaus, A. D. M. E. and Fouchier, R. A. M. Mapping the antigenic and genetic evolution of influenza virus. Science. 305, 371–376, 2004.
59. Soda, K., Ozaki, H., Sakoda, Y., Isoda, N., Haraguchi, Y., Sakabe, S., Kuboki, N., Kishida, N., Takada, A. and Kida, H. Antigenic and genetic analysis of H5 influenza viruses isolated from water birds for the purpose of vaccine use. Arch. Virol. 153, 2041–2048, 2008.
60. Song, H., Qi, J., Xiao, H., Bi, Y., Zhang, W., Xu, Y., Wang, F., Shi, Y. and Gao, G. F. Avian-to-human receptor-binding adaptation by influenza A virus hemagglutinin H4. Cell Rep. 20, 1201–1214, 2017.
61. Su, S., Qi, W., Chen, J., Cao, N., Zhu, W., Yuan, L., Wang, H. and Zhang, G. Complete genome sequence of an avian-like H4N8 swine influenza virus discovered in southern China. J. Virol. 86, 9542–9542, 2012.
62. Sun, H., Xiao, Y., Liu, J., Wang, D., Li, F., Wang, C., Li, C., Zhu, J., Song, J., Sun, H., Jiang, Z., Liu, L., Zhang, X., Wei, K., Hou, D., Pu, J., Sun, Y., Tong, Q., Bi, Y., Chang, K. C., Liu, S., Gao, G. F. and Liu, J. Prevalent Eurasian avian-like H1N1 swine influenza virus with 2009 pandemic viral genes facilitating human infection. Proc. Natl. Acad. Sci. U. S. A. 117, 17204–17210, 2020.
63. Suzuki, M., Okamatsu, M., Fujimoto, Y., Hiono, T., Matsuno, K., Kida, H. and Sakoda, Y. Potency of an inactivated influenza vaccine prepared from A/duck/Mongolia/245/2015 (H10N3) against H10 influenza virus infection in a mouse model. Jpn. J. Vet. Res. 66, 29–41, 2018.
64. Suzuki, M., Okamatsu, M., Hiono, T., Matsuno, K. and Sakoda, Y. Potency of an inactivated influenza vaccine prepared from A/duck/Hokkaido/162/2013 (H2N1) against a challenge with A/swine/ Missouri/2124514/2006 (H2N3) in mice. J. Vet. Med. Sci. 79, 1815–1821, 2017.
65. Tohari, A. M., Alhasani, R. H., Biswas, L., Patnaik, S. R., Reilly, J., Zeng, Z. and Shu, X. Vitamin D attenuates oxidative damage and inflammation in retinal pigment epithelial cells. Antioxidants. 8, 1–14, 2019.
66. Tsugawa, N., Suhara, Y., Kamao, M. and Okano, T. Determination of 25- hydroxyvitamin D in human plasma using high-performance liquid chromatography - tandem mass spectrometry. Anal. Chem. 77, 3001–3007, 2005.
67. Urashima, M., Segawa, T., Okazaki, M., Kurihara, M., Wada, Y. and Ida, H. Randomized trial of vitamin D supplementation to prevent seasonal influenza A in schoolchildren. Am. J. Clin. Nutr. 91, 1255–1260, 2010.
68. Vogel, A. J., Harris, S., Marsteller, N., Condon, S. A. and Brown, D. M. Early cytokine dysregulation and viral replication are associated with mortality during lethal influenza infection. Viral Immunol. 27, 214–224, 2014.
69. Yang, H., Carney, P. J., Chang, J. C. and Stevens, J. Molecular characterization and three-dimensional structures of avian H8, H11, H14, H15 and swine H4 influenza virus hemagglutinins. Heliyon. 6, e04068, 2020.
70. Zhang, H., Yang, N., Wang, T., Dai, B. and Shang, Y. Vitamin D reduces inflammatory response in asthmatic mice through HMGB1/TLR4/NF-κB signaling pathway. Mol. Med. Rep. 17, 2915–2920, 2018.
71. Zhang, X., Cunningham, F. L., Li, L., Hanson-Dorr, K., Liu, L., Waters, K., Guan, M., Olivier, A. K., Schmit, B. S., Nolting, J. M., Bowman, A. S., Torchetti, M. K., DeLiberto, T. J. and Wan, X.-F. Tissue tropisms of avian influenza A viruses affect their spillovers from wild birds to pigs. J. Virol. 2020.
72. Zhou, J., Du, J., Huang, L., Wang, Y., Shi, Y. and Lin, H. Preventive effects of vitamin D on seasonal influenza A in infants: A multicenter, randomized, open, controlled clinical trial. Pediatr. Infect. Dis. J. 37, 749–754, 2018.
73. Howley, M.; Knipe, D.: Orthomyxoriruses. In Fields Virology: Emerging viruses, 7th ed.; Whelan, S.; Wolters Kluwer: Philadelphia, PA, USA, 2021; Volume 1, pp. 650.
74. World Organisation for Animal Health. Avian influenza (infection with avian influenza viruses). Manual of diagnostic tests and vaccines for terrestrial animals. 2018. avaiable online: https://www.oie.int/standard-setting/terrestrial- manual/access-online/ (accessed on 6 Dec, 2020).