The FDNY shut down 26 firehouses across the Big Apple as of 7:30 a.m. Saturday because of staff shortages caused by the vaccination mandate, The Post has learned. Rep. Nicole Malliotakis, a Republican who represents Staten Island and Brooklyn, tweeted Saturday that five of the companies were in her district — and said it’s Hizzoner who could have blood on his hands. “If someone dies due to a slower emergency response, it’s on Bill de Blasio and his overreaching mandates. I hope this fool fixes it ASAP!” she tweeted. Twenty six companies out of service is an unconscionable number,” said Councilman Joe Borelli, a Staten Island Republican who chairs the committee on fire and emergency management. “The firefighters who are unable to work have all been tested within the week and are not Covid positive, and I doubt New Yorkers care about the vaccine status of the person applying defibrillators to their chest.” The FDNY’s vaccination rate was at 72 percent at the end of Friday. the city’s deadline for workers to get at least one shot of the Covid vaccine. The mandate is expected to be enforced beginning Monday. The NYPD’s number stood at 84 percent vaccinated. The FDNY blamed the short staffing on firefighters calling out sick, with one insider saying “hundreds” of firefighters have been taking medical leave to protest the mandate. “It’s definitely a sickout. It’s a job action,” the insider said. “If they call in sick they have to go to the medical office. The medical office is overwhelmed