Patterns and outcomes of late onset thyroid disturbances after COVID‐19 vaccination: A report of 75 cases.

Isolated cases of subacute thyroiditis exist in the early period of COVID‐19 vaccination, largely after mRNA vaccines. Here we report late onset thyroid disturbances and persistent health issues in patients of thyroid disorders after COVID‐19 vaccination. Seventy‐five patients with post COVID‐19 vaccination thyroid disturbances were identified. Among these, 41 had flare of underlying thyroid illness, majority occurring at a median time lag of 28.4 weeks since 2nd dose. Thirty‐one cases of new onset hypothyroidism and three of new onset hyperthyroidism were reported, with a median time lag respectively of 17.2 and 22.6 weeks since 2nd dose. Most cases occurred after ChAdOx1‐nCoV‐19, which was the commonest vaccine employed in mass roll out in India. Significant improvement was observed in majority, after a median follow up of 22–26 weeks. New onset health issues persisting for ≥4 weeks were reported in 37.3% and were common in individuals with history of COVID‐19 before vaccine. New onset metabolic, musculoskeletal, and reproductive disorders were the common health complaints. Active monitoring is warranted for late onset adverse events after COVID‐19 vaccines of all types. Larger studies with involvement of unvaccinated individuals are required to understand the incidence and causality of late onset thyroid disturbances after COVID‐19 vaccines. [ABSTRACT FROM AUTHOR]