Experts expect vaccinated individuals will need booster shot within a year Last month, we told you about Sheri Houghland, a local healthcare worker who came down with COVID even though she was vaccinated. Posted at 2:14 PM, May 26, 2021 and last updated 2021-05-26 18:21:37-04 (WXYZ) â Last month, we told you about Sheri Houghland, a local healthcare worker who came down with COVID even though she was vaccinated. She had only mild symptoms and recovered quickly. While breakthrough cases can happen, they are incredibly rare. And so, a bigger question looms around Houghland's incident. Had she lost immunity? "As a nurse, Iâve been vaccinated, really one of the first people in the community thatâs been vaccinated," Houghland said. "Iâve been vaccinated since about November."