Senator Joe Manchin hosted several senators, including Lindsey Graham on his houseboat during the weekend.Graham stated that he had tested positive for COVID-19 Monday morning.Manchin and Sens. Graham was in touch with Jacky Rosen, Mark Kelly and others on board the boat.10 Things in Politics: Keep up to date with the most recent political and economic news. Loading Something is loading. Click Sign up to receive marketing emails and other offers from Insider.Senator Joe Manchin, a West Virginia Democrat, hosted a number of lawmakers over the weekend at his Washington, DC homeboat. He announced that he had tested positive for COVID-19 despite having been fully vaccinated.Manchin's spokesperson told reporters that Manchin, who is also vaccinated in the wake possible exposure, will be following federal health guidelines.The spokesperson stated that Senator Manchin was fully vaccinated according to CDC guidelines.Arizona Democrat Sen. Mark Kelly and Nevada Democrat Sen. Jacky Rosen attended the gathering, where they met Graham, spokespeople said to CNN and other outlets. Their spokespeople stated that both senators are fully vaccinated and are following CDC guidelines.It is not clear who attended the gathering at Manchin's houseboat. This is the place where the veteran lawmaker resides while he is in DC. Insider reached out to Manchin's spokesperson but he did not immediately respond.The CDC recommends that anyone who has been exposed to COVID-19 should be tested within 3-5 days. They also need to wear a mask indoors for at least two weeks until the test is negative.Graham tweeted that he had tested positive for flu-like symptoms on Monday morning. Graham was immunized by Pfizer last December, and expressed relief that he had been vaccinated before he contracted the illness.He wrote, "I feel like a sinus infection. At the moment I have mild symptoms." "I will be in quarantine for ten days. I'm glad I got vaccinated. Without vaccination, I doubt I would feel the same way. I would have much worse symptoms.The number of COVID-19-related cases is on the rise in the US, especially in those areas with low vaccination rates. The US's weekly average number of daily new cases has nearly quintupled in the past month. It went from 12,000 at June's end to almost 72,000 on Thursday last week.According to the CDC, new data has shown that even though people have been vaccinated, they can still get "breakthrough infections". These cases are usually mild. The most transmittable strain of the virus, Delta, now accounts for more than 80% US infections.The House still has a mandate for masks, but the Senate does not. Nearly all senators claim they are vaccinated. However, dozens of House members refuse to say if they are. After moving back to in person meetings, Senate Democrats have resumed their leadership meetings online, despite the increase in cases.