%0 Journal Article %T Solar activity cycles recur epidemic and pandemic viruses: Space weather’s alerts %J Al-Azhar Bulletin of Science %I Al-Azhar University, Faculty of Science (Boys) %Z 1110-2535 %A Mawad, Ramy %A Madbouly, Hanafy M. %A Mahdy, Ehab M. B. %D 2022 %\ 12/01/2022 %V 33 %N Issue 2-B %P 71-83 %! Solar activity cycles recur epidemic and pandemic viruses: Space weather’s alerts %K Climate Change %K environment %K Epidemiology %K Solar cycle %K Solar terrestrial connection %K Space weather %R 10.21608/absb.2022.149409.1197 %X This paper studies pandemic viruses that spread during the period (1759-2020) according to solar activity cycles. Our findings and results include the following: (1) the pandemic severity level has a negative correlation with the strength of solar activity; (2) pandemic viruses are of three types according to their compatibility with solar activity association. Most of them spread through the quiet Sun, where viruses survive better in cold and rainy weather; (3) the emergence of new strains of influenza viruses was manifested in two ways. First, the annual epidemics due to antigenic drift. Second, pandemics recur at 1-12 solar cycles (~11-120 years) due to new virus subtypes resulting from virus reassortment which leads to antigenic shift; (4) pandemic viruses have two groups according to their recurring period: first, recurring in nine solar cycles; second, recurring in twelve solar cycles. Furthermore, we reassort pandemic viruses from their previous spread in the same periodic classification. Moreover, we derive a periodicity formula of each subtype of pandemic viruses as spread date. %U https://absb.journals.ekb.eg/article_258249_41821d8157a677dd33b32d9563e5b59f.pdf