Updated at 4:30 p.m.

ST. LOUIS — Eligible Missouri residents on Friday can begin receiving COVID-19 vaccine doses at 81 Walmart and Sam’s Club pharmacy locations across Missouri, including Shrewsbury and Ferguson in the St. Louis area.

The doses are sent to the pharmacies through a new partnership with the federal government. The locations were selected by federal officials.

On Wednesday afternoon, the Walmart sign-up website was displaying a warning that the schedule system was having technical difficulties the company was trying to fix. Later, the warning was gone, but searches of the site still showed no St. Louis-area immunization locations. A representative with Walmart did not immediately respond to questions.

Eligible customers, which includes those over the age of 65 with certain underlying health conditions, can schedule a vaccine appointment through the Walmart and Sam’s Club websites “once appointments become available,” according to the press release.

“In conversations with the White House and our federal partners, these pharmacies were selected by them in the designated areas because of their accessibility for many Missouri communities and the trust pharmacies have built with their patients,” said Dr. Randall Williams, director of the Missouri Department of Health and Senior Services.

Another 21 Health Mart locations will also soon begin administering vaccine as part of the federal program, according to a press release by Missouri’s health department. No date was given.

Together, the 102 Missouri retail pharmacies are scheduled to receive a total of more than 18,000 doses per week, according to the press release, which will be in addition to the approximately 93,000 doses a week the state receives to distribute to vaccine providers.

In Illinois, health officials continue to greatly expand the state’s use of retail pharmacies in its vaccine rollout plans.

The Illlinois Department of Public Health announced on Wednesday that the state is adding 110 pharmacies to its list of vaccination locations, bringing the total number offering vaccine across the state to 411.

The pharmacies include Walgreens, Hy-Vee, Jewel-Osco, Kroger and Mariano’s. Locations can be found online at coronavirus.illinois.gov.