Moderna Vaccine Nears US Approval: How Does it Compare to Pfizer?

Moderna's coronavirus vaccine is 'highly effective,' found a US Food and Drug Administration's analysis, clearing the way for emergency approval as soon as this week.

Once cleared, it will be the second vaccine approved in the US for emergency use. The US has already bought nearly all the available stock of the vaccine.

It will also be the second mRNA vaccine to receive approval, a new technology never before used to vaccinate the population.

Here's all you need to know about the vaccine and its development.

How Does Moderna Compare to Pfizer Vaccine?

The FDA review confirmed the earlier assessment that the Moderna vaccine had an efficacy rate of 94.1 per cent across a trial of 30,000 people. Fever, headache and fatigue were some of the side effects reported, but these were common and not dangerous.

Some experts say the side effects in Moderna vaccine are more common than seen in Pfizer BioNTech vaccine.

Moderna performed better in preventing more severe disease, though more data is needed to establish this. Its efficacy though was lower than Pfizer vaccine in population above 65 at 86.4 per cent.

Another possible difference that emerged was in protection - Pfizer seems to offer protection within 10 days after the first dose. Moderna did not observe such levels of protection after the first dose. Moderna's vaccine will be distributed 28 days apart to 21 days for Pfizer.

It's important to note that researchers don't know yet how long the protection will last in both vaccines, and whether those who receive the vaccine will not spread the virus to others.

Unlike Pfizer, no serious allergic reactions have been observed so far in Moderna's vaccine. Bell's Palsy, a temporary facial paralysis, was observed in both vaccines in a few volunteers, though researchers say the number was not significant.

Both are mRNA Vaccines

Both vaccines prime the immune system to attack the coronavirus by delivering a snippet of the virus’s genetic code called messenger RNA or mRNA. mRNA instructs the body to build copies of the spike protein that are found on the surface of coronavirus. The immune system creates antibodies, primed to attack the virus if it enters the body.

Moderna vs Pfizer: Which Vaccine is Easier to Distribute?

Moderna. Because it requires a significantly lesser extreme temperature to store. Experts say Moderna will do better in rural areas and private clinics, while Pfizer will perform better in hospital settings. Moderna can be stored in minus 13 to 5 degree Fahrenheit, while Pfizer requires a cold storage temperature of minus 75 degree Fahrenheit.

What Do these Developments Mean for India?

Pfizer vaccine has applied for emergency approval in India. But it is important to note that the cold chain requirements for the vaccine make it very difficult to distribute. The vaccine, if approved, will be given only via government contracts.

Moderna requires significantly easier cold chain, but compared to Oxford AstraZeneca's vaccine or even Bharat Biotech's Covaxin, the requirements are still higher.

More importantly, stocks of these vaccines have already been bought over by the developed world. It's unlikely these vaccines will be available for the developing world any time soon.