Just in time for Christmas, your elderly loved ones will get a vaccine – if they want it.

All Moderna covid vaccines for South Carolina will go to long-term care facilities until all their residents have had an opportunity to be vaccinated, according to Laura Renwick of the Department of Health and Environmental Control.

Unlike the Pfizer vaccine received last week, the Moderna vaccine has several advantages.

It does not have to be kept in super-freezer conditions, but it does have to be refrigerated.

It also comes in smaller lots of 100 doses, about a 10th of how the Pfizer vaccine is packed.

This will make it easier for local pharmacies, rural health care facilities, retirement communities and others to dispense.

“We are told CVS and Walgreens will start vaccinating LTCFs (long-term care facilities) with Moderna vaccine beginning the week of Dec. 28,” Renwick said.

“This is a federally coordinated program with CVS, Walgreens and the CDC. DHEC’s role is limited to providing some of the state’s vaccine allocations.”

Moderna is made by a Massachusetts vaccine developer in a partnership with the National Institutes of Health.

Its efficacy rate is 94.1% in preventing covid. How does it work?

The covid virus uses proteins to enter human cells. These proteins become targets for vaccines.

Like the Pfizer-BioNTech vaccine, Moderna’s uses RNA, a genetic material that our cells read to make proteins. The molecule is fragile and would be chopped to pieces by our natural enzymes if it were injected directly into the body.

To protect the vaccine, Moderna wraps the molecular RNA in oily bubbles made of lipid nano-particles.

Because of their fragility, the mRNA will quickly fall apart at room temperature. Moderna’s vaccine needs to be refrigerated and should last up to 6 months when shipped and stored at –4°F.

After injection, the vaccine particles fuse to cells, releasing mRNA. The cell’s molecules read its sequence and build spike proteins. The mRNA from the vaccine is eventually destroyed by the cell, leaving no permanent trace.

Like the Pfizer vaccine, Moderna’s vaccine requires 2 injections 28 days apart.

This primes our immune systems well enough to fight off the virus. But because the vaccine is so new, researchers don’t know how long its protection lasts.

If you take the Modern shot, you need a 2nd Moderna shot. If you take Pfizer, you need a 2nd Pfizer shot. The 2 vaccines cannot be mixed.