More than 40,000 people in Florida have not gotten their second shots of a coronavirus vaccine within the recommended time frame to do so, raising questions about why that may be happening.
Both of the coronavirus vaccines approved for use in the United States require two doses per person to be fully effective, with Pfizer-BioNTech recommending a second dose after three weeks and Moderna vaccine doses scheduled four weeks apart, although experts say it’s not critical that second doses be administered in exactly those time frames.
More than 1 million people in Florida have received at least one dose of a COVID-19 vaccine, according to state data from Tuesday. Of those, about 100,000 came back for their second shots and another 44,000 were listed in state data as overdue for second doses.
On Wednesday, the state published its latest vaccine data but omitted the number of people overdue for second doses. When asked why that detail was no longer included, Florida Department of Health spokesman Jason Mahon said the state removed it to better “align” with data reporting from the U.S. Centers for Disease Control and Prevention and to avoid confusion because people can still get second doses after the recommended time frame.
Prior to Wednesday, the number of people listed as overdue for their booster shots had fluctuated in state reports, with the number growing or shrinking somewhat depending on the day.
It’s not clear exactly why tens of thousands of Floridians may not be getting second doses in the recommended time frame. When asked last week, Florida Surgeon General Scott Rivkees said he could not speak to why it was happening but urged people who are scheduled for second doses to get them.
Mary Jo Trepka, an infectious disease epidemiologist and professor at Florida International University, said Floridians should be cautious about reading too much into the data without understanding why people are being listed as overdue. She noted that there has been some lag in data reporting, and added that it’s not clear to what extent the erratic vaccine supply and organizational issues with vaccine distribution have played.
The issue of people getting second doses in a timely manner is key to getting the most out of the vaccines, Trepka said.
“The state Department of Health considers it important enough that they’re listing it separately,” she said in an interview Tuesday, before the data point was omitted from the Wednesday vaccine report. “They’re taking it seriously.”
Trepka noted that people who are overdue for second doses should still get their second shot and they do not need to repeat the first shot.
The recommended schedule for getting second doses is based on the vaccines’ clinical trials, she said, and the companies were trying to complete the trials quickly so the vaccines could be approved for emergency use.
“It’s possible the best intervals were times longer than one month,” Trepka said. “But our only data is from those trials.”
The first shots of the Pfizer-BioNTech and Moderna vaccines prime the body’s immune response and have effectiveness of roughly 50 percent, while the second doses amplify recognition and immune response and bring effectiveness to greater than 90 percent.
Experts have been concerned from the beginning about making sure people get both vaccine doses, said Michael Teng, an associate professor in the Morsani College of Medicine at the University of South Florida.
“Those of us who have been talking about vaccines for a while have been trying to get people to understand that this is a two-dose vaccine,” Teng said.
Public health officials and medical experts have seen that many people don’t return for second doses for other vaccines that also require multiple doses, such as those for Hepatitis A or shingles. Teng and others said good communication and appointment reminders can help, as can offering vaccines in places that are convenient and comfortable for people.
Sonja Rasmussen, a professor at the University of Florida’s College of Medicine and College of Public Health and Health Professions, said it’s likely that many of the Floridians getting access to vaccines this early in the process are motivated to want to get both doses, and that it may become more difficult later in the process to ensure people are coming back for round two.
So far, the only people in Florida eligible to get vaccinated are health care workers, residents and staff of long-term care facilities and people ages 65 and older who sign up, as well as those deemed by hospital providers to be “extremely vulnerable” to the coronavirus.
Rasmussen said there have been some “mixed messages” about the importance of second doses right now. She pointed to news earlier this year that British health authorities plan to delay second doses of their approved vaccines in order to give out more first-round doses.
Gov. Ron DeSantis has said he is committed to Floridians getting both doses of the vaccines.
Rasmussen noted that the number of cases and deaths from the coronavirus are skyrocketing and that it’s important people understand that the vaccines are safe and that any side effects are better than getting the disease.
“People need two doses of the vaccine,” Rasmussen said, noting that she’s gotten both doses. " If you haven’t gotten (your second shot), it’s time to get it.”
Times staff writer Kirby Wilson contributed to this report.
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