READ THIS NEXT: Dr. Fauci Warns All Americans “Need to Pay Attention” to This Now. Health experts are warning that BA.5 has already kickstarted a new COVID wave in the U.S., prompting higher rates of infections and reinfections. According to a recent ABC News analysis of state data, there have been more than 1.6 million COVID reinfections across 24 states, as of June 8. But experts warn that the actual number of people catching COVID again right now is likely even higher than this. “These are not the real numbers because many people are not reporting cases,” Ali Mokdad, PhD, an epidemiologist with the University of Washington’s Institute for Health Metrics and Evaluation in Seattle, told ABC News. During a July 13 interview on CNN’s New Day, top White House COVID adviser Anthony Fauci, MD, confirmed that he is concerned about the BA.5 variant because it has a “transmission advantage” over prior versions of the virus—even the original Omicron variant BA.1 and formerly dominant Omicron subvariants BA.2 and BA.2.12.1. The infectious disease expert told news anchor John Berman that this newly dominant subvariant’s “ability to infect an individual is enhanced” because of its heightened ability to evade immunity from both vaccination and natural infection.ae0fcc31ae342fd3a1346ebb1f342fcb According to Fauci, the BA.5 variant is “the reason why” the U.S. is seeing a reported 140,000 COVID cases a day—although Fauci agreed that even this is “likely a gross underestimate” of the number of actual infections, as many people are testing themselves with at-home COVID kits and not reporting positive results to state agencies. “So we’re probably seeing a multifold greater number than that 140,000. Deaths are still around 300, but hospitalizations are ticking up,” he told Berman. “This is something you don’t want to panic about, but you really want to pay attention to it, because there are things that we can do to blunt that.” RELATED: For more up-to-date information, sign up for our daily newsletter. Like many other virus experts, Fauci continued to stress the need for more Americans to get vaccinated—noting that only 67 percent of the population has been fully vaccinated. But according to the infectious disease expert, that’s not the only mitigation tool available that people should be utilizing amid BA.5’s spread. When asked if people should be wearing masks indoors again, Fauci said that the CDC “makes it very clear” that people “really should, in an indoor setting, a congregate setting, be wearing masks.” The agency’s guidelines recommend that people in areas with moderate to high COVID transmission wear a mask indoors, no matter if they’re vaccinated or not. According to Fauci, there have been a “fair amount” of areas moving from low virus transmission a couple months of ago to moderate and high spread now. The CDC’s latest data shows that 58.5 percent of communities in the U.S. have at least a medium level of COVID transmission, as of July 7. And in the past week, the number of high-level counties and medium-level counties has increased by 1.3 percent and 2.4 percent, respectively. “[Masking indoors] is just the appropriate thing to do to defend, to protect yourself and your family, and those around you, because you could get infected and inadvertently, without any symptoms, transmit it to someone perhaps in your own household, who’s vulnerable, either an elderly person or someone with immune compromise,” Fauci said.