After three consecutive days of technical failures that frustrated residents trying to secure vaccine appointments last week, D.C. implemented a series of changes to its vaccine website. The results, so far, seem positive: Eligible residents who went through the appointment-booking process on Thursday report that the tech improvements made for a much smoother experience.

Still, Thursday’s appointments were booked in less than seven minutes. There were only 5,750 appointments available on Thursday — a supply significantly smaller than the number of residents who qualified based on their age, medical conditions, and zip code. (DC Health limited Thursday’s appointments to people in “priority zip codes,” as part of its efforts to correct for the disproportionate number of vaccines that have been going to residents of whiter and wealthier neighborhoods.)

Ahead of Thursday, DC Health and its technology partners simplified the online questionnaire for vaccine sign-ups, removed the captcha that thwarted many residents trying to secure appointments last week, and implemented a “virtual waiting room” that allowed only 3,000 users to access the questionnaire at a time. DC Health and the Office of the Chief Technology Officer also said they worked with Microsoft to increase server availability.

Another notable change this week was the arrival of the one-shot Johnson & Johnson vaccine to the District. Health experts, including local officials with DC Health, encourage residents to take the first shot available to them.

For this week only, DC Health also changed the eligibility requirements for appointments. Like last week, seniors and people with qualifying medical conditions were eligible — but for just this week, people in eligible workforce groups were not permitted to sign up for vaccine appointments via the DC Health portal.

Joyful residents who were able to book appointments called the process “100% different” from last week and said it worked “flawlessly” for them.

Still, others said that while the website did not crash like last week, they got through to the questionnaire only to find that all the vaccine appointments had been booked.

The page in the virtual “waiting room” — which DC Health and its technology partners said was implemented to prevent users from overloading the system — emphasized that the District currently has a limited supply of vaccine.

“Thank you for your patience,” it said. “We will get through this together.”

Then, it added, in all caps, “DC NEEDS MORE VACCINE.”

D.C. will once again open 5,750 appointments up to eligible seniors and people with qualifying medical conditions on Friday at 9 a.m. But this week will be the last week the District will use its current online registration system, which some residents have described as a kind of “Hunger Games” where residents are pitted against each other to see who can secure one of the limited appointments the fastest.

Critics of the current system have emphasized that it privileges computer-savvy residents with fast Internet connections because of how quickly the appointment slots fill each day on the website.

Next week, the city will start using a pre-registration system to schedule appointments. Residents will be able to upload their information by using the DC Health website or call center. Then, instead of having to be at the ready, dialing their phones and logging on to a website exactly at a certain time, they will be notified via email and either a phone call or text message to let them know they can make an appointment.