The Centers for Disease Control and Prevention鈥檚 recent guidance on students and masking 鈥渓acks a well-grounded scientific justification.鈥
Florida Gov. Ron DeSantis in a July 30 executive order

On July 30, Florida Gov. Ron DeSantis issued an stating that schools couldn鈥檛 mandate that their students wear masks, and that it should be up to parents to decide whether they want their children masked in school buildings. The order also said the state can deny funding to districts that don鈥檛 comply.
One part of the order particularly caught our attention because of what it said about masks: 鈥淲HEREAS, despite recent Centers for Disease Control and Prevention (CDC) 鈥榞uidance,鈥 forcing students to wear masks lacks a well-grounded scientific justification; indeed, a Brown University study analyzed COVID-19 data for schools in Florida and found no correlation with mask mandates.鈥
The executive order came on the heels of the , which recommended that everyone age 2 and up should wear masks whether they are vaccinated or not. This guidance was issued partly because of the increase in covid cases due to the delta variant, which is more contagious than other versions of the virus. It was also issued because covid vaccines have not yet been authorized for use in children under age 12.
During the pandemic, DeSantis, a Republican, has consistently taken positions contrary to public health guidance from experts and said he wants Florida to remain open.
鈥淚n Florida, there will be no lockdowns, there will be no school closures, there will be no restrictions and no mandates,鈥 DeSantis said during a speech introducing the executive order, which drew immediate pushback. President Joe Biden criticized and a group of Florida parents to block the order.
But the state is currently considered a covid hot spot. The聽聽there were 134,506 new cases of COVID-19 from July 30 to Aug. 5. That鈥檚 compared to 11,837 new cases over the earlier week-long period beginning June 4, before the delta variant surge. Hospitalizations have also increased. Total聽聽on Aug. 9, compared to a聽聽as of June 6.
DeSantis鈥 executive order cites a Brown University study to support his argument that schools can鈥檛 mandate masks.
We reached out to DeSantis鈥 office to confirm the role of that study and to ask if any other research was involved in the development of the executive order.
Press secretary Christina Pushaw replied with a statement reiterating the governor鈥檚 position that studies have shown covid鈥檚 spread in schools is typically less than within the larger community and that science has yet to substantiate the effectiveness of masks in reducing what she said was 鈥渁n already very low risk of COVID-19 in children.鈥 She acknowledged that the delta variant has been shown to be more transmissible 鈥 which means it could increase children鈥檚 risk 鈥 鈥渂ut that is only a working theory as no studies have shown that conclusively.鈥
That made us wonder about key elements of the executive order 鈥 specifically, whether the Brown study indeed illustrated that mask mandates didn鈥檛 prevent transmission of covid-19 and if it鈥檚 correct that 鈥渇orcing students to wear masks lacks a well-grounded scientific justification.鈥
The Brown Study
We reached out to , a professor of economics at Brown University, and the lead author of the that DeSantis鈥 order references. Oster became well known during the pandemic for issuing data-driven recommendations on parenting and schooling. Some with her being an economist and not an epidemiologist.
Oster told us she couldn鈥檛 participate in a direct interview about the study, but she sent us this statement:
鈥淲e did not consult with Gov. DeSantis on these issues. Our paper is currently a pre-print, undergoing peer review. It relies on data from the 2020-2021 school year, prior to the emergence of the more contagious delta variant. Current CDC guidance, taking into account the current virus situation and all available data on masking, suggests masking for all K-12 students and staff, regardless of vaccination status.鈥
The study analyzed whether mask mandates in school districts in Florida and other states influenced the number of covid cases among students and staff members by looking at mitigation strategies as well as covid case counts. The researchers found that staff rates of covid were slightly higher in districts without mask mandates, but the difference was not statistically significant. Overall, no correlation was found between mask mandates and covid cases in students.
But within the study itself, the authors wrote about the limitations of their methods.
For instance, the study looked only at whether mandates existed at particular schools 鈥 not at the mask-wearing behavior of students and staffers. The study also didn鈥檛 account for mitigation measures that might have been in place in the surrounding community, which would influence case counts.
At the end of the study, the authors offer a conclusion that undermines the executive order: 鈥淲e would emphasize that in general this literature suggests in-person school can be operated safely with appropriate mitigation, which typically includes universal masking. It would be premature to draw any alternative conclusions about this question based on this preliminary data.鈥
, an epidemiology professor at the University of North Carolina, who led a that found masking in schools was associated with a significantly reduced risk of covid transmission, said he didn鈥檛 think this Brown study showed any strong conclusions to support the governor鈥檚 position.
鈥淚 think the lack of correlation with mask mandates at the population level is pretty weak evidence,鈥 Lessler wrote in an email. 鈥淎lso, mechanistically, it is a little hard to believe masking would not have some effect.鈥
Other Studies on Masks in Schools and Covid in Children
, dean of the Milken Institute of Public Health at George Washington University, said masks are absolutely effective in reducing covid transmission in children.
鈥淲hat the science actually shows is that for children ages 2 and above, masks are not only protective but needed,鈥 said Goldman, who is also a pediatrician. Since 鈥渢hose kids who are below the age of 12 cannot yet have the vaccine so they don鈥檛 have that layer of protection.鈥
Goldman also said in preventing covid transmission in schools.
The CDC guidance also cites several that show the benefits of masking in schools, while have shown similar results. Masking was often combined with other efforts to reduce spread, including improved ventilation and filtration systems.听
These points counter a claim central to DeSantis鈥 executive order: that the CDC school-reopening guidance 鈥渓acks a well-grounded scientific justification.鈥
鈥淚 think this 鈥榳hereas鈥 of DeSantis鈥 executive order is just false, it鈥檚 just patently false,鈥 said , a pediatrics professor at the University of Florida Health in Jacksonville.
What About Infection Risks for Children?
Though studies early in the pandemic did seem to indicate children were less likely to get covid than adults, current CDC data suggests that no longer seems to be the case.
through March 2021 shows that covid infection and symptomatic illness in children ages 5 to 17 was comparable to infection and illness in adults ages 18 to 49. have also shown that even if children have mild or asymptomatic cases of covid they can spread the disease to adults who may then develop more severe cases 鈥 meaning children can be significant vectors of disease.
Children also are susceptible to the delta variant, which is more transmissible than the alpha variant.
Goldhagen said he has already anecdotally heard and seen the spread of the delta variant among children in camps and in schools that have started their semesters.
Pediatric covid hospitalizations have in the past week, likely due to the delta variant, and there are reports that some children are experiencing serious symptoms. 鈥淭he increase in the number of patients that we have in our children鈥檚 hospital due to covid has increased 500%,鈥 Goldhagen, who is also a pediatrician at Wolfson Children鈥檚 Hospital in Jacksonville, told us on Aug. 5.
Our Ruling
DeSantis鈥 July 30 executive order missed the mark with its claim that 鈥渇orcing students to wear masks lacks a well-grounded scientific justification.鈥
It also cited a Brown University study as scientific evidence that there is no correlation between mask mandates and reduced covid spread. However, while that study didn鈥檛 show a correlation, its authors noted the study鈥檚 limitations and concluded that appropriate mitigation typically includes universal masking. It flatly stated it would be premature to draw other conclusions based on the researchers鈥 preliminary data. Multiple studies also show masking in schools does have an effect on preventing covid transmission.
DeSantis鈥 executive order cherry-picked a study that offers little basis for his position and includes a variety of elements that are not accurate. We rate this False.
Source List
ABC Science Collaborative, , June 2021
Bloomberg, 鈥,鈥 Aug. 8, 2021
Centers for Disease Control and Prevention, , May 28, 2021
Centers for Disease Control and Prevention, , March 26, 2021
Centers for Disease Control and Prevention, , accessed Aug. 9, 2021
Centers for Disease Control and Prevention, , updated July 9, 2021
Centers for Disease Control and Prevention,, July 9, 2021
Centers for Disease Control and Prevention, , updated July 27, 2021
Department of Health and Human Services, , accessed Aug. 9, 2021
Email interview with , epidemiology professor at the University of North Carolina-Chapel Hill, Aug. 5, 2021
Email interview with , associate professor at the University of South Florida College of Public Health, Aug. 3, 2021
Email statement from , economics professor at Brown University, Aug. 3, 2021
Email statement from Christina Pushaw, press secretary for Gov. Ron DeSantis, Aug. 4, 2021
Harvard Medical School, , Aug. 2, 2021
medRxiv, , May 21, 2021
The Miami Herald, updated Aug. 9, 2021
National Bureau of Economic Research, , May 2021
NBC 6 South Florida, 鈥,鈥 Aug. 6, 2021
The New York Times, 鈥,鈥 June 22, 2021
Office of Gov. Ron DeSantis, July 30, 2021
Phone interview with , associate professor at the University of South Florida College of Public Health, August 3, 2021
Phone interview with , pediatrics professor at the University of Florida Health in Jacksonville, Aug. 5, 2021
Phone interview with , dean of the Milken Institute School of Public Health at George Washington University, Aug. 6, 2021
Reuters, 鈥,鈥 July 31, 2021
Science, 鈥,鈥 June 4, 2021
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