There is no evidence of kalonji seeds being useful in the treatment of COVID-19 and the World Health Organisation has not recommended it.
World Health Organization (WHO) has not recommended kalonji seeds for the treatment of COVID-19. There is no evidence that current medicine can prevent or cure the disease. WHO does not recommend self-medication with any medicines, including antibiotics as a prevention or cure for COVID-19.
The COVID-19 pandemic has given rise to a lot of potentially dangerous misinformation. For reliable advice on COVID-19 including symptoms, prevention and available treatment, please refer to the World Health Organisation or your national healthcare authority.