A state-sponsored COVID-19 vaccination and booster shot site at Boston’s Fenway Park reopened Thursday. Appointments for the clinic are available for booking online and walk-ins will also be accepted.Health officials said the clinic will have the capacity to administer 1,500 doses per day, with 1,000 reserved for appointments and 500 reserved for walk-ins. During the ballpark’s first run as one of Massachusetts’ mass vaccination sites, more than 55,000 doses were administered. The operation moved from Fenway to the Hynes Convention Center at the end of March, to make way for the start of the baseball season.Dirk and Sofia Borden got a booster shot at Fenway Park Thursday, along with some bragging rights. “Just cool being at Fenway Park, a place I’ve been my whole life — just felt weird going for a different reason, but it was pretty easy, staff was really friendly, a good time,” Dirk Borden said. Children between the ages of 12 and 15 are urged to get a third Pfizer shot. The third shot is recommended five months after the second.Two thirds of Americans in that age group are fully vaccinated.”The overwhelming majority of kids who are hospitalized with COVID are not vaccinated, either because they’re not eligible or because they haven’t yet gone out and gotten the shot,” said Dr. Alok Patel, of Standford Children’s Health.CDC Director Dr. Rochelle Walesnky released a statement late Wednesday night saying “This booster dose will provide optimized protection against COVID-19 and the Omicron variant. I encourage all parents to keep their children up to date with CDC’s COVID-19 vaccine recommendations.”