Absentee ballots are now available in the city clerk’s office for the Oct. 15 primary in the special election to fill the vacant Fifth Congressional District seat. Seven candidates are vying in a Democratic primary and three in a Republican primary that day. The seat became open when Edward J. Markey resigned after his election to the US Senate in June. Any registered voter unable to vote on Election Day due to absence from the city, physical disability, or religious belief is eligible to vote by absentee ballot. The deadline for filing an application for an absentee ballot is Friday, Oct. 11, at 5 p.m. City Hall, which normally closes at 1 p.m. on Fridays but will be open until 5 p.m. on Oct. 11 to accommodate those seeking ballots. For more information, call the clerk’s office at 781-897-5850.