Why administering Covid-19 Shots is so difficult

© CB Schmelter / Associated Press

The application of Covid-19 vaccines in locations across the country is only the first step in vaccinating the population. Taking them out of the freezer and putting them in their arms is another journey, complicated by the special handling that doses require, but also because of the complicated data management systems. Web sites must take precautions to ensure that they do not contribute to the spread of the virus, measures that can delay the administration of vaccines. And in many places, the demand for doses has exceeded supply.

The Tennessee Riverpark vaccination site in Chattanooga, Tennessee, administers the vaccine to about 3,500 people a week, which is typical for a location of its size and the number of doses it is receiving. In operation since December 23, the process has become smoother over the weeks, health officials say. Close examination of the distribution center highlights the many people and processes that must align before doses can be administered quickly and efficiently.

Vaccines from Pfizer Inc. and Moderna Inc. have different handling requirements, storage protocols and guidelines for thawing and dosing time.

Storage: facilities that handle both vaccines need to be equipped with three types of freezers and refrigeration units. One capable of storing the Pfizer vaccine in deep freezing, another one for storing the Modern vaccine and then a refrigerator used for defrosting. The crucial components of vaccines can easily destabilize if they are not stored at the right temperature.

Health workers at vaccination sites are constantly managing freezing, chilling and thawing times. At the same time, they need to be careful that the thawed vaccines are not left unused beyond the expiration date. The Pfizer vaccine can remain thawed after dilution for six hours before expiration. For the Modern vaccine, the period is also six hours.

Managing and recording vaccine temperatures takes time. Outdoors, vaccines need to be transported by hand as needed, so that workers can ensure that doses are not too hot or cold in the elements. Before injections are administered, doses are thawed at room temperature.

Handling: A thawed Pfizer vaccine requires several steps before being placed on an arm.

Workers should place a bottle containing five or six doses at room temperature for up to 30 minutes before preparation. Then, the vaccine must be inverted 10 times to mix the contents thoroughly. Workers then place a diluting agent in a syringe and inject it into the Pfizer vaccine bottle. They invert the villain another 10 times. The mixed solution is then placed in five or six syringes for dosing. The Modern vaccine does not require dilution, but must be manually shaken before doses are administered. Each vial of Moderna contains 10 doses.

The Pfizer vaccine is sensitive to light. Inside the trailer where health workers prepare doses at the Chattanooga site, blinds are usually kept closed to block the sun.

They place loaded syringes in trays and sometimes use paper bags to cover the trays. They wrap the trays in plastic in case of rain.

Vaccines are in high demand, and many vaccination sites have faced problems with limited supplies, causing hiccups.

Security: fears of stolen or tampered vaccines have prompted many county health departments and hospitals to pay local police to administer doses between storage facilities and vaccination sites. Some sites hire police officers to keep doses 24 hours a day.

Crowd management: Although states, counties and vaccination sites have prioritized certain groups for vaccination, people who do not qualify often show up without an appointment, waiting to be vaccinated. Some people lie to get an appointment, health officials say. In Chattanooga, the National Guard is on site and people are required to prove that they qualify for the appointments they have booked. The paperwork must be completed beforehand, but many end up filling it out on the spot. Verifying that a person has an appointment and is qualified requires extra time. No one is allowed to come more than 15 minutes before an appointment to avoid crowding.

Immediately after receiving the injections, people should go to a waiting area for at least 15 minutes so that they can be monitored for possible allergic reactions. In many places, this requires large indoor spaces capable of socially distant seats or huge parking lots.

Scheduling and data: Even with an adequate scheduling system, planning appointments for two doses of two different vaccines is complicated to manage. In many places, there are “first dose” days and “second dose” days, Pfizer days and Modern days. Many vaccination sites prefer a separate day system to avoid errors involving varying vaccine protocols.

At first, there were hiccups. Vaccine shipments did not arrive or were not consistent. Some health departments say they are still not sure whether they are getting vaccines until they receive a delivery notice from FedEx Corp. – and do not schedule the first doses until those doses are in place.

As doses are administered, there are several documentation requirements, such as recording the demographic data of the dose recipients and recording the vaccines they received. Most health departments must manually enter this information into complex databases that are usually separate from scheduling systems.

Write to Julie Wernau at [email protected]