Reemerging ‘Cicada’ COVID-19 variant sparks conversation and concern

Other posts spread false claims about heart inflammation and COVID-19 vaccines and debated vitamin K injections at birth.

A reemerging COVID-19 variant that may be more likely to affect children drew concern from parents and conspiracy theories from vaccine opponents. Meanwhile, a January study reignited the false claim that COVID-19 vaccination increases risk of heart inflammation more than infection. Finally, social media users discussed how vaccine hesitancy is increasingly causing some parents to refuse vitamin K injections for newborns.

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What’s trending in vaccine conversation:

Late last year, the COVID-19 variant BA.3.2—nicknamed Cicada—reemerged in the U.S. after nearly a year of dormancy. New evidence suggests that the variant, which is on the rise in the U.S., may be more likely to infect children compared to previous variants. Recent news coverage of the variant has been met with apathy from those who claim COVID-19 is no longer a public health concern. Some social media users used the reemergence of a COVID-19 variant to argue that vaccines are not effective and to attempt to discredit mRNA vaccines. Others speculated that BA.3.2 is a “distraction” from more pressing issues, such as the 2026 U.S. midterm elections. Several posts focused on the evidence that children may be more vulnerable to the variant, with some expressing concern that many incorrectly believe COVID-19 does not pose any risk to children.

Some vaccine opponents are using a January study on COVID-19 vaccine safety and effectiveness to falsely claim that COVID-19 vaccination increases the risk of heart inflammation more than COVID-19 infection in children and adolescents. A preliminary version of the study fueled similar claims when it was uploaded in May 2024, prompting the study’s authors to push back against the misrepresentation of their research. In recent weeks, social media users have used the research to misleadingly claim that rare heart inflammation only occurred after COVID-19 vaccination but not after infection, failing to acknowledge that the study did not analyze heart inflammation after infection.

A March 21 article prompted online discussions about how vaccine hesitancy can influence other health decisions. Much of the discourse centered on parents opting out of vitamin K injections, which prevent fatal bleeding in newborns. Many posts supported the injections and emphasized that they are not vaccines, but others opposed giving infants injections of any kind. Several users debated the necessity of vitamin K at birth, while others advocated for use of oral vitamin K drops, which are less effective and not FDA-approved. Some posts also expressed concern about reactions to the injection.

Read the fact checks: 

• PolitiFact: What we know about the new COVID-19 variant ‘cicada’ or BA.3.2. 
• USA Today: Oxford study on myocarditis and vaccine misrepresented
• UC Davis Health: Facts and myths parents should know about vitamin K shots for newborns

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Recommendations for public health professionals

The Infodemiology.com team will provide messaging recommendations in response to some of the trending narratives outlined above. Use these helpful tips when creating content, updating web pages and FAQs, and developing strategy for messaging about vaccines.

As a reemerging COVID-19 variant fuels false claims and concern online, health communicators may explain that experts say the updated 2025-2026 COVID-19 vaccine still helps prevent severe illness from circulating variants and that current COVID-19 treatments and tests remain effective. Messaging may emphasize that there is currently no evidence that the variant is more severe or contagious than other recent strains. Encouraging community members—including parents and older adults—to talk to a health care provider about a spring vaccine dose is recommended.

Misrepresented research about heart inflammation often circulates online. Debunking messaging may explain that large-scale studies have consistently shown that COVID-19 vaccines are the best way to protect against COVID-19, reducing the risk of infection, severe illness, long COVID, and hospitalization in people of all ages, including children and teens. Health communicators may emphasize that heart inflammation after vaccination is extremely rare and typically mild and that COVID-19 infection is associated with a far higher risk of heart inflammation.

As vaccine hesitancy spills over into non-vaccine treatments, messaging may continue to emphasize the safety and importance of vitamin K injections to protect newborns. Health communicators may emphasize that since 1961, pediatricians, including the American Academy of Pediatrics, have recommended that all newborns receive a single, low-dose vitamin K injection at birth. Additional messaging may highlight that the vitamin K injection is not a vaccine but rather a lifesaving treatment to prevent vitamin K deficiency bleeding, a rare but deadly condition. Explaining the risks of skipping the injection is recommended, as is highlighting the decades of evidence showing that the vitamin K injection is safe for newborns.