Throughout the COVID-19 response, our goal has been to provide real-time data on all aspects of the COVID-19 pandemic, including cases, hospitalizations, laboratory results, and vaccines. Ensuring rapid distribution of vaccine to high-risk groups is a critical component of public health during a pandemic response. Surveillance of vaccine administration data is especially important when trying to monitor the impact of vaccine in our communities. 

Today, we are reporting a number of total vaccinations in Arizona that is lower than the number reported yesterday. As with other real-time data we receive and report on COVID-19, such as cases reported, an important part of the process is checking the data at regular intervals to find and correct any duplications by matching the data from different data reporting streams. The new, validated number becomes the basis for continued real-time reporting. Meanwhile, finding duplicates in data addresses issues and improves the real-time data we report daily. Accurate data takes time and involves many steps. Similar to the first time we completed our death data matching, the first merging, matching, and cleaning of data usually results in a significant change in the number of records identified and removed (or added).

Unlike cases and deaths, the requirement of two doses of COVID-19 vaccine requires additional steps for data matching and deduplication. In addition to determining whether two reports are for the same person, we also have to validate whether that individual has a duplicate report of the first dose being administered, which would need to be deleted. If a report is for their second dose, that is considered a validly administered dose, which would not be deleted from our database. The availability of multiple presentations is also factored into the data review.

As a result of this routine data cleaning, we are reporting a number of total vaccinations in Arizona that is lower than the number reported yesterday. As we merged vaccine data, we identified some duplicate reports that needed to be removed from the total doses administered. Today’s number of doses administered statewide is 113,993. You can find a breakdown of these numbers by county on our website.

We continue to work with local public health officials to ensure that vaccines are going into the arms of Arizonans. Many counties will move into phase 1B next week, opening up the eligibility for even more to receive the vaccine. The data matching also brings us one step closer to adding the vaccine data to our daily data dashboard updates. We’re hoping to have the data update in real-time on a daily basis in the coming week.