The medical worker in Xi'an, Shaanxi province who contracted novel coronavirus in mid-March after vaccination was likely infected when obtaining throat swabs for imported cases, and her chronic rhinitis condition had probably increased susceptibility to the disease, a study released on April 20 has shown.

The female worker was responsible for collecting and testing samples in a quarantined local hospital designated to receive imported COVID-19 cases. She completed a two-dose vaccination regime on Jan 20, and was confirmed of infection on March 17.

Antibody tests show that the medical worker had generated high levels of immune response, and her mild symptoms and quick recovery have added to growing evidence that although none of the COVID-19 vaccines across the world report a 100 percent efficacy rate, they are highly effective in curbing severe infections and death, it added.

The research was published online by the China CDC Weekly, an academic platform set up by the Chinese Center for Disease Control and Prevention. It was conducted by researchers from the China CDC and local disease control officials in Shaanxi province.

The research results have underscored the significance of adhering to rigorous disease control measures after vaccination, especially for medical workers who work in high-risk environments.

It is also vital for them to wear and use personal protective equipment appropriately and abide by good clinical practices, the research said.

The potential role of chronic upper respiratory infections, such as allergic rhinitis and asthma, in increasing the risk of infection, is also worth further research, it added.