A soldier was rushed in very serious condition with pneumonia to Hadassah University Medical Center in Ein Kerem on Sunday. The hospital said he was attached to a ventilator and sedated in the respiratory intensive care unit. A woman soldier - who also was part of a group of soldiers who contracted pneumonia at the Tzukei Uvda base in the south - is in serious condition at Soroka University Medical Center in Beersheba. She was previously in critical condition, but she has been stabilized. On Sunday, about 500 new draftees were released from their base in the south after 13 of their comrades were diagnosed with pneumonia. Three others are hospitalized in Eilat, but they are out of danger. The Israel Defense Forces' Medical Corps is investigating the incident. The Health Ministry said it is not involved, as the infection was an internal military matter. The draftees had been vaccinated against influenza. The IDF has said it has not found the source of infection and has not disclosed if it is viral or bacterial. The military base's water, food and ventilation systems were tested, and nothing unusual was found, the IDF said.