They’re number three on the COVID-19 vaccine depth chart, but they may be #1 in your hearts … or at least your wallets. AstraZeneca became the third pharmaceutical manufacturer to claim a vaccine with at least 90% effectiveness when delivered in two doses. If they can get emergency-use authorization, the Oxford-based vaccine might take the lead in both distribution and cost — or so the company claims.

There’s only one catch, and it’s an odd one. In order to get to 90% effectiveness, the first injection has to be a half-dose rather than a full dose. No one’s quite sure why:

To quote the old beer commercial, why ask why? Just deliver this in the manner that gets the best results. At any rate, this is excellent news, especially for poorer nations that might have otherwise had to wait longer for the other vaccines:

The coronavirus vaccine developed by the University of Oxford and the British-Swedish pharmaceutical giant AstraZeneca is up to 90 percent effective when administered at a half dose and then a full booster dose a month later, scientists said Monday.

The announcement follows upbeat results from two other front-running vaccine candidates, by Pfizer-BioNTech and Moderna, in the last two weeks.

The Oxford-AstraZeneca vaccine is likely to be cheaper than those made by Pfizer and Moderna, and it does not need to be stored at subzero temperatures but can be kept in ordinary refrigerators in pharmacies and doctor’s offices.

AstraZeneca executives said the vaccine is already being manufactured. The first 4 million doses could be ready in December, and 40 million could be delivered in the first quarter of 2021, they said. By the spring, the company and its global partners in India, Brazil, Russia and the United States could be cranking out 100 million to 200 million doses a month.

That’s a bit slower than Pfizer and Moderna, who have been manufacturing all along and have tens of millions of doses at the ready. However, if the manufacturing costs are lower, that would explain how they can ramp up quickly to those levels of production — globally, mind you, not in the US. The other two, with their boosts from Operation Warp Speed, are still the most likely to be the front line for the US.

This could still alleviate pressure on American distribution, even if AstraZeneca is a secondary player here. The US has been under pressure to share its vaccine production globally, and Joe Biden has pledged to put the US into the global partnership on vaccine development and distribution. (Donald Trump refused, preferring the America First approach.) This would allow the US to keep its Operation Warp Speed production from Pfizer and Moderna while helping to supply the AZ vaccine in surplus for global distribution.

That suits Oxford and AstraZeneca just fine:

Oxford researchers and AstraZeneca stressed that they aren’t competing with other projects, and that multiple vaccines will be needed to reach enough of the world’s population and end the pandemic.

“We’re not thinking about vaccinations working in terms of one person at a time. We have to think about vaccinating communities, populations, reducing transmission within those populations, so that we really get on top of this pandemic,″ said Sarah Gilbert, a leader of the Oxford research team. “And that’s what it now looks like we’re going to have the ability to contribute to in a really big way.″

Their vaccine might make it easier to penetrate in poorer countries, too. The lower cost will make a big difference in those areas:

The Oxford-AstraZeneca vaccine is also cheaper. AstraZeneca, which has pledged it won’t make a profit on the vaccine during the pandemic, has reached agreements with governments and international health organizations that put its cost at about $2.50 a dose. Pfizer’s vaccine costs about $20 a dose, while Moderna’s is $15 to $25, based on agreements the companies have struck to supply their vaccines to the U.S. government.

Those are remarkably inexpensive for a new drug with this kind of life-saving potential. The cost differences matter in bulk, however, especially with needed doses in the billions or perhaps tens of billions. If the effectiveness is the same, the cheaper vaccine might be better directed to where resources are the most strained. Plus, the far-easier handling of the AZ vaccine makes it much easier to distribute in places where refrigeration of any kind is scarce, let alone the specialized refrigeration that the Pfizer vaccine will require:

Storage presents challenges for all three drugmakers when it comes to the distribution of the vaccines. According to AstraZeneca, its COVID-19 vaccine can be stored, transported, and handled at 36 to 46 degrees Fahrenheit – normal refrigerator conditions – for at least six months. It can also be administered in a traditional healthcare environment.

Moderna’s COVID-19 vaccine can be stored at negative 4 degrees Fahrenheit for up to six months or at 36 to 46 degrees Fahrenheit for up to 30 days.

Pfizer and BioNTech’s COVID-19 vaccine requires a temperature of minus 94 degrees Fahrenheit, which would require special storage equipment for storage and transportation, which the companies say they have developed. The vaccine can be stored for up to five days refrigerated at 35 to 46 degrees Fahrenheit.

It’s almost a Godsend for underdeveloped nations, in other words. The vaccines for Pfizer and even Moderna aren’t well suited for that kind of distribution. That will take pressure off of both economic strata, and hopefully spread herd immunity far more rapidly around the planet than otherwise might have been the case. If this holds up under review, maybe everyone gets a gold medal.