As the holidays approach, here is what we know about three vaccines against COVID-19. The Oxford/AstraZeneca vaccine is up to 90% effective in both young and old people when a half dose is given, followed by a full dose one month later. When two full doses are given one month apart, however, the effectiveness drops to 62%. This vaccine will cost about $4 per dose. This vaccine can be stored at fridge temperature (2-8°C). The Pfizer/BioNTech vaccine is the first vaccine to be submitted to the U.S. Food and Drug Administration (FDA) for emergency use. This vaccine is 95% effective 28 days after the first dose. Pfizer said this vaccine could be available to high risk populations in the U.S. by late December 2020. This vaccine may cost about $20 per dose, but it must be stored in very cold temperatures (−70°C). The Moderna/NIH vaccine is 94.5% effective. Moderna tested this vaccine in the U.S. in over 30,000 people (7,000 over 65 years and 5,000 under 65 years) with high risk long-term diseases. More than one third of the people in the trial were people of color. Moderna will ask the FDA for emergency use authorization soon. Moderna’s vaccine can be stored in a household fridge for 30 days, at room temperature for up to 12 hours, and at −20°C for up to 6 months. However, this vaccine is much more expensive than the other two, costing about $35 per dose. Many other companies are also creating vaccines against COVID-19.