Tri-State hospitals report 'low' number of staff out sick due to COVID vaccine side effects While a small number of vaccinated health care workers have had to call out sick due to the shots' side effects, officials say it's a "quite low" number and the majority have continued working. and last updated 2021-02-08 19:13:08-05 As more and more Tri-Staters receive one of two COVID-19 vaccinations currently available, doctors are learning more about the side effects that could accompany the dual-injection treatments. Those side effects were strong enough for a small number of vaccinated health care professionals to have to call off work in the days following their shots.