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COVID-19 Vaccine Boosters: How Long Is Allowed Between Doses?

Hospital news | Wednesday, February 17, 2021

Contact: Terry Moss

There is a sense of urgency coupled with gratitude for those 1,808 patients who have received the initial COVID-19 vaccine in the last eight weeks. There is an understandable worry once that initial dose is given about reports of vaccine shortages. There is also a concern that boosters won't be administered soon enough to remain effective due to lack of supply.

"A lot of people are under the impression they have to have the vaccine at exactly twenty-eight days, or it's no good," said Giselle Grimes, RN, Memorial Hospital of Converse County's Infectious Disease Specialist. And to be fair, that's what many news, healthcare organizations, and public health officials have communicated since the roll-out of the Moderna vaccine from the FDA. But like all things COVID-19, be prepared for a certain amount of flexibility as we discuss the subject of vaccine booster guidelines.

According to the CDC website on COVID-19 vaccine administration, "Persons should not be scheduled to receive the second dose earlier than recommended." The site then goes on to state that "second doses administered within a grace period of 4 days earlier than the recommended date for the second dose are still considered valid." The CDC also advises that the second dose should be administered as close to that twenty-eight-day interval as possible, implying a certain level of flexibility as MHCC calls to schedule those booster doses. The second injection doesn’t have to be exactly twenty-eight days later and the time of the second dose can be extended nearly double that amount of days.

This flexibility on the window of time is allowable because of how the shot works. The 1st shot stimulates your immunity to know and create protections. The 2nd injection then reminds B and T cells of the immune system that the threat cannot be taken lightly and to attack the virus quickly.

The main thing to realize however is, "the second dose will still be effective if it is administered outside of that twenty-eight-day window," continued Grimes. Both the Pfizer and Moderna vaccines "can be given up to six weeks (forty-two days) after the first dose. There is no need to start the cycle over if that vaccine is not given at day twenty-eight exactly. The second dose will still achieve ninety-five percent efficacy if given up to forty-two days after the first dose” she concluded.

A significant hindrance to administering the second round is the limited availability of the COVID-19 vaccines. “Like so many hospitals and healthcare organizations in the state and nation, we are reliant on shipments of vaccines which can come in at different intervals around a patient’s twenty-eight day window,” said Chief Nursing Officer Cristy Dicklich-Cobb. "We are constantly improving our processes and working diligently to get those all-important boosters into arms as close to the twenty-eight-day window as possible.”

Darcey Cowardin, County Nurse Manager with the Converse County Public Health, shares similar sentiments on the twenty-eight day window. “While getting your second dose at twenty-eight days is the target, sometimes due to scheduling it may not be possible,” she said in a written statement. “As mentioned before, the vaccine is still effective and doses don’t need to be repeated if you can’t get your second dose right at twenty-eight days.”

Noting the concern of patients’ worries of supply shortages for boosters she continued, “the Wyoming Department of Health holds back 2nd doses from the original inventory and sends a matching quantity three weeks later. Rest assured, Converse County is receiving 2nd doses and working hard to get them out there as close to the twenty-eight day mark as possible.”

The person handling the calling and scheduling is "the voice of Memorial Hospital of Converse County," herself Amy Cullen. "We are doing our best to call promptly to notify patients when we are low and waiting for a fresh shipment of the vaccine," she shared in a written statement. "We are now letting patients know upfront the possibility of being rescheduled based on varying shipment sizes. We are doing our very best to keep patients’ appointments in order of receiving their calls.”

Understandably, many patients are concerned when informed there will be a delay in receiving their second dose. “Lots of patients have heard that it has to be 'exactly twenty-eight days,' and many are feeling the need to quarantine themselves until they've had the second dose," Cullen continued. "which is understandably frustrating when appointments get pushed back. But so far, it's been an average of one week, sometimes more, based on other factors like travel or illness.”

Cullen has worked to reassure patients in the last weeks that the dates on their cards are not an appointment but represent the "soonest possible date" for their second dose. "We take this seriously and are not wanting to jeopardize our patients' health in any way. It's our privilege to serve our community. We appreciate all the kindness, understanding, and flexibility they have shared with us as we all navigate these 'new waters' together.”

If patients have concerns about getting their second dose or need to ask questions about the COVID-19 vaccines they are encouraged to call the MHCC COVID-19 Vaccine Hotline at: 307-359-5371. Patients are encouraged to call to check-in to get their name on the schedule, and those that do usually fare better than waiting for a call.

“A kind word does go a long way. It may take some time, but we will get this done,” Cullen concluded.

To find information on the administration of the COVID-19 Vaccines via the CDC website, click here.