As much as we want to put it behind us, COVID-19 isn’t going away. Cases are currently rising across the country in a summer surge.The U.S. Centers for Disease Control and Prevention (CDC) reports that cases of COVID-19 are increasing in nine states and likely growing in another 16. The trends are estimates, as the CDC no longer conducts rigorous surveillance of cases based on results from lab tests. Fewer people are also getting tested. But the data do provide a hint of how the disease is changing over time, and new monitoring systems that track viruses in wastewater confirm the rise.[time-brightcove not-tgx=”true”]The CDC says that the overall level of respiratory diseases in the U.S.— COVID-19, flu, and RSV—remains “very low,” but that emergency room visits for COVID-19 are on the rise, accounting for 0.5% of emergency room visits in the country as of mid July, compared to 0.3% of cases at the beginning of the summer. While that may seem like a small increase, emergency room visits are a bellwether for disease trends, since they represent cases in which people are sick enough to seek care. “We are starting to hear about more young kids or older adults showing up in the emergency room with COVID-19,” says Dr. Luis Ostrosky, chief of infectious diseases at UT Health Houston. Texas is one of the states seeing spikes in infections.Here’s what experts say you need to know about the current surge in cases.Why are COVID-19 cases increasing in the summer?Unlike most respiratory diseases like the common cold and flu, which generally peak during the winter, COVID-19 tends to spike twice and sometimes three times a year: once in the fall and winter, once in spring, and another time in the summer. While viruses tend to spread more easily when people are gathered indoors during cold weather, the post-winter time periods also coincide with “travel, vacations, and people congregating and going to events,” says Ostrosky.COVID-19 trends also depend on the emergence and spread of new variants. The latest, including NB.1.8.1, are getting better at spreading among people, which contributes to a bump in cases.Read More: What to Do About Your Red, Itchy EyesAnother factor that could be driving the surge in infections is that fewer people are getting vaccinated, for a number of reasons. U.S. health authorities recently changed COVID-19 vaccine recommendations, continuing to recommend yearly shots for older people and those who have weakened immune systems, but allowing otherwise healthy adults more leeway to decide whether to get vaccinated. Many experts, however, continue to encourage people to get them. “What I tell my colleagues and patients is that we need to follow the evidence, and the best evidence out there is not controversial,” says Ostrosky. “Vaccines are safe and very effective in preventing severe disease, hospitalizations, mortality, and Long COVID.” It’s important for most people to get vaccinated every year to maintain good protection against severe disease, he says, and for those with weaker immune systems, including the elderly, to get vaccinated twice a year. “I can’t tell you how many times I’ve heard patients ask, ‘Do COVID vaccines still work? Am I still supposed to get them?’” With less focus on the vaccines, education and awareness about them is dropping, he says, and that could fuel upticks in cases.Where is COVID-19 rising?According to the latest CDC estimates, the virus is growing in Arkansas, Illinois, Iowa, Kentucky, North Carolina, Ohio, Pennsylvania, Texas, and Virginia. The agency’s models find that there is a 95% chance that the epidemic is growing, which means more states could start to see increases in infections.What is the latest dominant COVID-19 variant?Omicron variants still account for all new infections in the U.S., with NB.1.8.1 responsible for 43% of cases as of the end of June. However, the CDC says the low number of cases reported to the agency means the data may not reflect the latest situation.Will the vaccine protect me from COVID-19?The current version of the vaccine targets a different, older Omicron variant, but it remains effective in protecting against severe disease because the viruses are closely related. “Not only are they all Omicron, but they are from a specific branching of Omicron that is pretty well conserved over the past year and a half,” says Ostrosky. “So I have pretty good confidence that the vaccine remains a good match for circulating variants.”