In this Monday, July 27, 2020 file photo, a nurse prepares a syringe during a study of a possible COVID-19 vaccine, developed by the National Institutes of Health and Moderna Inc., in Binghamton, N.Y. Credit: Hans Pennick / AP

A federal panel recommended the second coronavirus vaccine for emergency use in the U.S. on Thursday with final approval from the Food and Drug Administration likely on Friday in a step that will sharply increase capacity across the country.

The vaccine from Moderna is similar to the Pfizer vaccine already being used across the country. But it differs in some key ways that will instantly make it more available, with the first shipment going to nearly 3,300 sites nationally compared to just over 600 for Pfizer.

In Maine, the new vaccine means that capacity will nearly double. More rural hospitals are expected to get their first dedicated doses next week as pharmacies mobilize to vaccinate staff and residents at skilled nursing and other residential facilities. Here’s what you need to know.

How do the vaccines work?

The vaccines are similar. Both vaccines require two doses, with 21 days between shots for the Pfizer vaccine and 28 days for the Moderna vaccine. They also use messenger RNA, a massive scientific advancement that has long been studied but has never before been authorized by the U.S. in a vaccine, according to the U.S. Centers for Disease Control and Prevention.

While vaccines traditionally use weak or inactive versions of a pathogen to give people immunity, the mRNA vaccines contain genetic material providing instructions for the body’s cells to make a piece of the protein unique to the coronavirus. The body responds by producing antibodies that fight off what it believes is an infection and produces an immune response.

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How many doses will Maine get and where are they going?

One of the challenges with the Pfizer vaccine is that it must be kept at super-cold temperatures that require special freezers both for shipment and storage. Moderna’s vaccine is shipped at a higher freezing temperature, but it can be stored in a refrigerator for 30 days compared to only five days for the Pfizer vaccine.

This makes it much easier to roll out on a large scale. While Maine’s first shipment of the Pfizer vaccine brought just over 12,000 doses, nearly half went to just seven hospitals in cities with the required freezers while the rest went to long-term care facilities.

Maine’s first Moderna shipment will increase statewide capacity to more than 50,000 doses, bringing 22,000 alone to more than three dozens hospitals across the state. Nearly 11,000 will be set aside for retail pharmacies to vaccinate staff and residents of skilled nursing and residential facilities, according to the Maine Department of Health and Human Services.

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Are the vaccines safe and effective?

Yes, according to their FDA reviews. They look to be roughly equivalent. The vaccine starts working after the first dose and clinical trials showed the Moderna vaccine to be 94.1 percent effective in preventing infection after two doses, just below Pfizer’s mark of 95 percent. It is unclear how long they provide protection.

Adverse reactions to the vaccines have been common, but that is normal and the vast majority have been mild to moderate. The Moderna vaccine saw slightly more than the Pfizer vaccine, with 91.6 percent in trials experiencing injection site pain, 68.5 percent experiencing fatigue, 63 percent headaches, 59 percent muscle pain, 44.8 percent joint pain and 43.4 percent chills.

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Michael Shepherd

Michael Shepherd joined the Bangor Daily News in 2015 after three years as a reporter at the Kennebec Journal. A Hallowell native who now lives in Augusta, he graduated from the University of Maine in...