Second Dose COVID-19 Vaccination Updates from Polk County Health Department

February 23, 2021

(Des Moines, IA) – COVID-19 vaccination continues to remain a top priority for Polk County and we continue to be limited by the amount of vaccine that our community is receiving. We receive weekly allocations of both the Moderna and Pfizer vaccinations, both require a second dose approximately a month apart for maximum protection against COVID-19. Brands of vaccine cannot be interchanged.

In January, we saw larger allocations of Moderna than Pfizer. The Polk County Health Department made a planning assumption that the supply of both brands would continue to increase and in an effort to get as many people vaccinated as quickly as possible, used all available doses as the first in the series. We did not receive the anticipated increase in supply, leaving Polk County with 14,000 people who need to receive their second Moderna dose. We continue to receive approximately 10,000 doses per week but the majority is now Pfizer.

At this time, the priority of the health department is to focus on providing second doses. Limited first dose appointments are still being scheduled at clinics and select pharmacies using the Pfizer vaccine.

This means that you may not receive your second dose of the Moderna vaccine on the exact day or week that it is due. While there may be a delay in receiving the second dose of the Moderna vaccine, the CDC states that the timing of your second dose will not compromise the effectiveness of your vaccination and you will not have to start the series over again. Recent research is showing that the first dose alone is providing up to 80% effectiveness in preventing COVID-19 infection.

According to the Centers for Disease Control and Prevention (CDC), the second dose should be administered as close to the recommended interval as possible. However, if it is not feasible to adhere to the recommended interval and a delay in vaccination is unavoidable, the second dose of Moderna vaccines may be administered up to 6 weeks (42 days) after the first dose. If the second dose is administered within the 42-day interval, there is no need to restart the series. There are currently limited data on efficacy of mRNA COVID-19 vaccines administered beyond this window. If the second dose is administered beyond these intervals, there is no need to restart the series.

Healthcare clinics and pharmacies will continue to provide first dose vaccinations to the eligible groups based on state and local public health guidelines. The Polk County Health Department clinic plans to focus on second doses and assisting our seniors 65 years and older who do not have a primary care physician. If you are eligible based on age, your primary care provider will notify you via phone, direct mail and/or through your health system website portal when you are eligible to call and schedule an appointment.

When you are eligible for your second dose at Polk County Health Department, you will receive an email with the opportunity to sign up for a second dose appointment. Vaccine supply is still limited, so you may be unable to schedule your second dose appointment immediately. Due to this issue, you will receive this email for three weeks beginning shortly before you are eligible for your second dose.

We will continue to work with our community and health systems to make sure our individuals in tier 1 receive their first dose in a timely manner. If current allocations continue, we anticipate that we will have all of the second doses caught up by April 12. When we resume scheduling first doses at the Polk County Health Department, we will schedule second doses at the time the first is administered.

We thank you for your continued patience and understanding. Please continue to wear a mask and practice social distancing.




COVID-19 Call Center for eligible individuals WITHOUT computer or internet access, please call 515-323-5221 Monday – Friday 9:00 AM – 4:30 PM.