According to the Centers for Disease Control and Prevention, the flu vaccine is the best way to protect people against the flu and prevent its spread. The flu vaccine can also reduce the severity of the flu if a person contracts a strain of the flu that the vaccine did not contain. It takes about two weeks following vaccination for antibodies to protect against the flu.
Some dentists do not routinely prescribe antibiotics and still have successful implant cases. Their success rate may increase with using antibiotics, but may not (it is all a matter of odds). You are likely fine, but may consider a different antibiotic with fewer side effects.
If that is not possible, such as is the case with some invasive medical procedures, including some types of dental work, then antibiotics may be recommended. There has been confusion, among doctors, dentists, and patients, about who should have antibiotics before having dental work. In the past, administration of antibiotics prior to dental work was only recommended during the first two years after surgery.