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August 6, 2020

​​​Media Contact:

Deidre McCabe, Director, Office of Communications, 410-767-3536

Charlie Gischlar, Deputy Director, Media Relations, 443-463-7234

Maryland Department of Health releases COVID-19 post-vaccination infections data

Data offer new pandemic insight as Maryland, like other states, continues to see rise in infections attributed to highly contagious Delta variant

Baltimore, MD—The Maryland Department of Health (MDH) yesterday released new COVID-19 post-vaccination infections data, adding to its robust COVID-19 data reporting available at The new data offer insight into the safety and efficacy of the COVID-19 vaccine as Maryland, like other states, continues to see a rise in the number of COVID-19 infections attributed to the highly contagious Delta variant.


“These data show clearly, and are another reminder, that vaccines are the most effective and critical tool in preventing COVID-19 infections, serious illness, hospitalizations, and death,” said MDH Secretary Dennis R. Schrader. “Anyone who is still unvaccinated remains at great risk of contracting and spreading COVID-19 and variants, hospitalization, and death.”


According to the Centers for Disease Control and Prevention (CDC), vaccine breakthrough cases—also called “post-vaccination infections”—are expected, as no vaccines are 100 percent effective. The main goal of the state’s COVID-19 vaccine initiative is to prevent severe illness and death. A percentage of fully vaccinated people may get sick, yet cases where fully vaccinated people are hospitalized or die from COVID-19 are rare. Vaccines remain the best way to prevent COVID-19 and its complications. 


People are considered fully vaccinated 14 days after receiving the last required dose of an FDA-authorized COVID-19 vaccine. Maryland identifies post-vaccination infections by matching vaccination data reported to the state immunization registry, ImmuNet, to a corresponding record of a positive COVID-19 test result. To be considered a post-vaccination infection, the person must be tested  at least 14 days after receiving the last required dose of COVID-19 vaccine. 


MDH identified Maryland’s first post-vaccination infection on Jan. 26. As of Aug. 1, MDH has identified 3,836 confirmed cases of COVID-19 among fully vaccinated Maryland residents, which represents less than 0.12 percent of Maryland residents who are fully vaccinated as of July 18. Of those total post-vaccination infections, 454 individuals were hospitalized and 53 individuals died. Maryland’s data suggest that the risk of hospitalization or death among the unvaccinated is about 25 times higher than among the vaccinated.  

“Maryland has made significant progress in vaccinating our population and this has now become, as the CDC has said, ‘a pandemic of the unvaccinated’,” said MDH Deputy Secretary for Public Health Dr. Jinlene Chan. “We urge every eligible Marylander who is not vaccinated to get vaccinated as soon as possible—if you have questions about the vaccine’s safety or efficacy, talk to your health care provider.” 

Maryland’s state and local health departments are working with the CDC to investigate post-vaccination infections. Additional information about vaccine breakthrough case investigation and reporting is available from the CDC.

To date, Maryland has administered more than 7.2 million doses of COVID-19 vaccine and reports 78.1 percent of the population aged 18 and older as having received at least one dose. 

The state continues to focus on making vaccines accessible to Marylanders through the No Arm Left Behind initiative, the Maryland Vaccine Equity Task Force, and the GoVAX Mobile Summer Tour. As of today, more than 700 pharmacy providers are listed on, and the state’s multilingual call center is available seven days a week at 1-855-MD-GOVAX. In addition, vaccines are available through more than 400 primary care providers across the state.

After completing a successful $2 million vaccine lottery, the state continues its $1 Million VaxU Promotion to provide $50,000 scholarships to 12- to 17-year-olds who get vaccinated through Labor Day.

To view COVID-19 data dashboards, visit Cases and vaccination data are updated daily during the 10 a.m. hour. Post-vaccination infection data will be updated weekly on Wednesdays. Additional visualizations for post-vaccination infections data will be added in the coming weeks.


For more information about COVID-19 in Maryland, visit


The Maryland Department of Health is dedicated to protecting and improving the health and safety of all Marylanders through disease prevention, access to care, quality management and community engagement. 

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