A new study by @YaleSPH @ChenKai_yale & team shows that SARS-CoV-2’s reproductive number is attributable to seasonal factors; temperature (3.73%), humidity (9.35%) and UV radiation (4.44%).

We need to vaccinate before the cold, dry, dark winter hits.https://t.co/s2e8kYUo6M

— Prof. Akiko Iwasaki (@VirusesImmunity) June 18, 2021