READ THIS NEXT: Vaccinated People Are “Extraordinarily Vulnerable” to This, New Study Finds. There have been almost 84 million reported COVID infections throughout the U.S. over the last two years, according to the CDC. But that’s just what has been officially reported. The agency recently reported that as of Feb. 2022, around 60 percent of the U.S. population had evidence in their blood suggesting that they have had a past COVID infection. That’s equivalent to almost 200 million Americans, as Time magazine notes.ae0fcc31ae342fd3a1346ebb1f342fcb “We know that the reported cases are just the tip of the iceberg,” Kristie Clarke, co-lead for the CDC’s COVID-19 Epidemiology and Surveillance Taskforce Seroprevalence Team, said during a press briefing on April 26. According to Time, cases can go undetected if people don’t develop symptoms, don’t get tested, or use at-home tests and don’t report positive outcomes to public health officials. If you’re among the many who have been infected with COVID but not yet vaccinated against the virus, you could be in danger. In a new alert, Ulysses Wu, MD, the system director of infection disease and chief epidemiologist for Hartford HealthCare, said that prior infection alone won’t be enough to keep people immune from reinfection this summer. “They are not safe. They can contract COVID again and there is a good possibility that the current virus may evade pre-existing immunity and infect again,” Wu said. According to Hartford HealthCare, reinfection rates are rising due to a combination of factors include length of time in the pandemic, immunity waning, lifted COVID mandates, and new, more contagious variants. RELATED: For more up-to-date information, sign up for our daily newsletter. The CDC advises that people get vaccinated against COVID even if they’ve already been infected with the virus. The agency notes that there can be a “wide range in antibody titers” as a response to infection, while the completion of a vaccine series usually creates a higher and more consistent antibody response. “Vaccinations are the best way to achieve immunity,” Wu confirmed. According to the CDC, you can consider waiting up to 90 days to get your vaccine after you’ve tested positive for COVID because your immune response after infection is likely highest throughout those three months. But after that, you do need to be vaccinated. “People who already had COVID-19 and do not get vaccinated after their recovery are more likely to get COVID-19 again than those who get vaccinated after their recovery,” the CDC warns. Vaccination is also important for those who have been previously infected in order to provide protection against COVID hospitalization if they are reinfected. A CDC study released April 15 looked at the protection afforded by mRNA vaccination during Omicron’s surge among people with a prior coronavirus infection. According to the study, vaccine effectiveness against a reinfection case that leads to hospitalization was estimated to be 35 percent after the second dose and 68 percent after a booster dose. “To prevent COVID-19–associated hospitalization, all eligible persons should stay up to date with vaccination, including those with previous SARS-CoV-2 infection,” the CDC concluded. “In general, protection by a hybrid of infection-induced and vaccination-induced immunity is superior to that from either alone and is less likely to wane over time.” READ THIS NEXT: Dr. Fauci Gave This New Warning to All Americans—Including Vaccinated People.