How the 4 biggest COVID-19 vaccines not available in the US compare with those that are

• Vaccines from the UK, Russia, China, and India are being used elsewhere to fight COVID-19.
• But they are not available in the US, which has only authorized jabs by US firms.
• Here is how the compare on metrics like ease of transport, efficacy, and cost.

The US has authorized three types of COVID-19 shot for its vaccine rollout: the Pfizer, Moderna and Johnson & Johnson shots. But they aren't the only options.

Around the world, other vaccines are being used, and will likely end up inoculating more people around the world than those used in the US.

Non-US shots include Sputnik V (made in Russia), AstraZeneca (made in the UK), Sinovac (from China) and Covaxin ( from India).

Here is how they compare with the US-approved vaccines on four key metrics:

EFFICACY

• Pfizer (US): 95%
  Authorized by the FDA and bolstered by positive real-world data.
• Moderna (US): 94.1%
  Authorized by the FDA also supported by good real-world data.
• Johnson & Johnson (US): 66%
  Trial results aren't published, but it won authorization from the stringent FDA.
• AstraZeneca (UK): 62% (though the figure is less straightforward than the others)
  Authorized by Europe's EMA agency and dozens of others around the world.
• Sputnik V: 91.6%
  Authorized in more than 40 countries, though not the US, EU, or UK.
• Sinovac: Unclear. One trial said 50.4% and another said 91.2%.
  Authorized in at least 15 countries, including Mexico, Turkey, and Thailand.
• Covaxin: 81% - it claims. There is no published data, making it hard to say for sure.
  Authorized only in India, Iran, and Zimbabwe.

Efficacy data is only one way to measure whether a vaccine works, and different trial results are not strictly comparable.

As long as a vaccine is safe and has an efficacy above 50%, experts say it is useful to combat COVID-19.

PRICE PER DOSE

Price figures can vary depending on location and who is buying, so the following are approximate:

• Pfizer: $20
• Moderna: $15-25
• Johnson & Johnson: $10*
• AstraZeneca: $4
• Sputnik V: less than $10
• Sinovac: varies widely - one report suggests the range is from $5 ito $38 in the Philippines.
• Covaxin: $3 or so

*Johnson & Johnson's is a one-shot vaccine, so requires half as many doses as the other vaccines.

TECHNOLOGY

• Pfizer and Moderna: Both vaccines use brand-new mRNA technology.
• Johnson & Johnson, AstraZeneca, Sputnik V: These three use the tried-and-tested combination of an adenovirus (a harmless virus shell) and DNA.
• Sinovac, Covaxin: These two use a deactivated version of the coronavirus, altered so that it can't make people sick.

STORAGE & EASE OF TRANSPORT

(This determines whether vaccines can safely reach remote and rural areas, especially important in poorer countries.)

• Pfizer: 6 months in at around -95°F, 5 days at around 35°F, 2 hours at room temperature.
• Moderna: 7 months in at -4°F, 30 days at around 35°F, 12 hours at room temperature.
• Johnson & Johnson: 3 months at around 35°F, 12 hours at room temperature around 70 degrees.
• AstraZeneca: 6 months at around 35°F.
• Sputnik V: 2 months at around 35°F.
• Sinovac: up to three years at around 35°F.
• Covaxin: at around 35°F.

When will these vaccines be available in the US?

It depends. Some makers may have no interest in the US market, which is already better-served than almost anywhere else.

AstraZeneca has said that it will seek approval for its vaccine from the US FDA in the next few weeks.

By contrast, a representative for Sputnik V told Insider in February that the company has little interest in the US market.

As for Covaxin and Sinovac, it isn't clear whether they would seek to apply to the FDA. Both the Indian and the Chinese vaccine have already been widely distributed elsewhere.

In the meantime, all the experts say that the best vaccine to get is the one that you are offered.