With more than a dozen COVID-19 vaccine candidates currently in late-stage clinical trials and dozens more not too far behind, it's now evident that not everyone in the world will get the same vaccine. Not only are there different manufacturers -- AstraZeneca, Johnson & Johnson, Norovax and so on -- but each vaccine is delivered and works a little differently from the others. Most COVID-19 vaccines come in the form of a shot, but some are patches and others you can swallow as pills. The vast majority require at least two doses, but a few are expected to provide effective immunity after just one.
That means it's possible some vaccines may be reserved for certain groups instead of others based on how the drugs act in the body or how they're delivered. For example, some single-dose vaccines might better serve low population density, rural communities, whereas city dwellers and suburbanites who live closer to more health care providers may get vaccines that require subsequent "booster" doses.
The vast majority of coronavirus vaccines are still under development and the science continues to evolve, so nothing is set in stone just yet. Here, we paint in broad strokes a picture of what the coming vaccine landscape may look like. We'll continue to update this story as new information comes to light. This article is intended to be a general overview and not a source of medical advice.
Pfizer and Moderna are available now
What they are: Both Pfizer's and Moderna's vaccines are mRNA, or "genetic," vaccines, an entirely new class of drugs that are unstable at room temperature and must be kept frozen until right before they're dispensed.
When they're coming: Both have been authorized by the US Food and Drug Administration and are currently being administered to priority individuals like health care workers as well as nursing home residents and staff.
Who they might be best for: So far, nursing home staff and residents and front-line health care workers.
Refrigeration: Pfizer's vaccine requires long-term storage colder than Antarctica: minus 94 degrees Fahrenheit. It can then be stored at normal refrigerator temperatures of 35 to 46 degrees Fahrenheit for up to five days. Moderna's needs temperatures that a commercial deep freezer could probably handle for long-term storage: minus 4 degrees Fahrenheit. It keeps at typical refrigerator temperatures (36 to 46 degrees Fahrenheit) for 30 days.
Dosing: Both vaccines require an initial injection followed by a booster shot several weeks later.
Oxford University/AstraZeneca vaccine could be next
What it is: Once the frontrunner in the race for a coronavirus vaccine, the candidate developed by Oxford University and British-Swedish pharmaceutical giant AstraZeneca has run into a few snags along the way, which have delayed its application for authorization.
Dosing: Two doses, originally intended to be spaced one month apart. Referring to unpublished results of the trial, however, regulators in the UK have authorized a three-month gap between doses, saying the data supports that window as the more effective time scale.
Novavax shows promise, and an advantage
What it is: The Novavax coronavirus vaccine is in late-stage clinical trials. Though it isn't on the road to approval yet, this vaccine shows promise in its high efficacy and its stability in regular refrigeration conditions, versus deep-freeze conditions. That could make it more practical for wider distribution.
When it's coming: Likely sometime in the first half of 2021.
There's no guarantee that any of the as-yet unauthorized vaccines listed above will be cleared by the FDA for emergency use, nor do any of the timelines take into account the potential for future snags or delays. We'll update this article as new information surfaces, and continue to add more vaccines to this list as it becomes clearer when other manufacturers might apply for authorization, as well as which groups are likely to receive them.
The information contained in this article is for educational and informational purposes only and is not intended as health or medical advice. Always consult a physician or other qualified health provider regarding any questions you may have about a medical condition or health objectives.