While I'm not a doctor, I'd say that I don't agree with this recommendation for people with autoimmune thyroid disease like Hashimoto's Thyroiditis and Graves' Disease. We know that people with autoimmune diseases have malfunctioning immune systems. We often have a more difficult time fighting off or receuperating from infection. Many of us find ourselves getting more colds, and taking longer to recover from them. We're more susceptible to allergies and asthma.
Wounds can even heal more slowly.
It makes sense to me that if there's a safe and effective vaccine that will offer tremendous protection from the flu, that it would also make sense to take advantage of this, rather than exposing ourselves to what might be an increased risk of getting the flu, and a longer receuperation time getting over the flu. These high-risk groups include all people aged 65 years or older and people of any age with chronic diseases of the heart, lung or kidneys, diabetes, immunosuppression, or severe forms of anemia. Persons aged 65 years or older. Residents of nursing homes and other chronic-care facilities housing patients of any age who have chronic medical conditions. Adults and children with chronic disorders of the pulmonary or cardiovascular systems, including children with asthma.