While the 95% efficacy rates for the Moderna and Pfizer/BioNTech vaccines are great news for the U.S. and Europe, Monday's announcement from Oxford and AstraZeneca may be far more significant for the rest of the world.

Why it matters: Oxford and AstraZeneca plan to distribute their vaccine at cost (around $3-4 per dose), and have already committed to providing over 1 billion doses to the developing world. The price tags are higher for the Pfizer ($20) and Moderna ($32-37) vaccines.

Details: The Oxford/AstraZeneca vaccine had an average efficacy of 70% in clinical trials, though that rose to 90% under one dosing regimen (patients received a half dose, and then a full dose one month later).

• While that fell short of numbers reported by Moderna and Pfizer, it's well above the 50% efficacy threshold set by the FDA.

The Oxford/AstraZeneca vaccine can also be stored at standard refrigeration levels for six months.

• Moderna's vaccine can be kept under standard refrigeration for 30 days but otherwise must be stored at -20°C
• Pfizer's must be stored at -70°C, a requirement that few developing countries are equipped to handle.

By the numbers: AstraZeneca has already promised 940 million doses to developing countries and another 300 million to the COVAX initiative, according to Duke University's tracker.

• Moderna is also a participant in the COVAX initiative, through which wealthier countries will subsidize access for poorer ones.
• But Moderna's chief medical officer told Axios last week that when it came to COVAX, the company hadn't "quite aligned with them on how many doses and when those doses would be available."
• Pfizer is not a participant in COVAX.

Breaking it down: Pfizer has sold a minimum of 614 million doses to high-income countries and just a combined 14 million in bilateral deals with lower-income countries (Ecuador, Lebanon and Peru), according to Duke's tracker.

• If rich countries exercise their options to buy more of the Pfizer vaccine, they could swallow up nearly all of the 1.3 billion doses the company aims to produce in 2021.
• Moderna has also been selling almost exclusively to rich countries.
• In addition to the 1.24 billion for developing countries, AstraZeneca has sold 1.17 billion doses to rich countries (the U.S., EU, U.K., Japan, Australia and Canada).

The flipside: AstraZeneca will manufacture its vaccine in multiple countries, including India and Brazil, and aims to produce a total of 100 million to 200 million doses per month by the spring.

• Both India (500 million doses) and Brazil (100 million) have secured their access to the vaccine, as have countries including Indonesia (1oo million), Bangladesh (30 million), Egypt (30 million) and Argentina (22 million), according to the Duke tracker.

What to watch: While countries like Canada, the U.S. and the U.K. have hedged their bets by buying enough doses of multiple vaccine candidates to cover their populations several times over, less wealthy countries are cutting deals wherever they can.

• At least 11 countries plan to obtain Russia's vaccine candidate, Sputnik V. The government says the vaccine is 92% effective and has given it partial approval, but has made only limited data available.
• China has also promised several countries access to its vaccine candidates, several of which are in late-stage trials.

Go deeper: Key information about the effective COVID-19 vaccines