Vaccination has little impact on post-COVID smell and taste issues, study shows

Researchers examining whether COVID-19 vaccination affects persistent smell or taste problems after contracting the virus have found that, in most cases, it does not. Dr. Daniel Hwang from The University of Queensland’s Institute for Molecular Bioscience led an international research team to investigate changes in smell and taste following COVID-19 vaccination, particularly among people who experienced persistent sensory changes after contracting the virus.

“We wanted to investigate anecdotal reports that having a COVID-19 vaccination helped people experiencing persistent smell or taste problems,” Hwang said. “But for more than 90% of study participants, smell and taste remained unchanged after their COVID-19 vaccination.

“People living with these symptoms may also be concerned about whether vaccination could make their condition worse. Our findings provide some reassurance that, for most people, this was not the case.”

Researchers conducted a multilingual survey of 1,352 vaccinated participants from 52 countries between May 2022 and August 2023, with about half having reported changes to their smell and taste after contracting COVID-19. The results are published in the journal Laryngoscope Investigative Otolaryngology.

The research was sparked by anecdotal reports of smell improvement after vaccination shared in a Facebook support group for people experiencing loss of smell and taste following COVID-19.

Among participants who already experienced conditions such as parosmia (where familiar smells become distorted), phantosmia (smelling things that are not present) and distorted taste, some reported improvement of their symptoms following vaccination, while worsening was relatively uncommon.

“However, because this was an observational study, we can’t say that vaccination caused these improvements, and natural recovery from COVID-related smell and taste problems may also have played a role,” Hwang said.

Hwang said the findings could help clinicians provide better information when counseling people with persistent post-COVID smell and taste problems who have concerns about vaccination.

“Ongoing changes in smell and taste can have a substantial impact on eating, nutrition, enjoyment of food and quality of life after COVID-19,” Hwang said. “The results also highlight the importance of clinicians assessing different types of smell and taste dysfunction separately, rather than simply asking whether someone has lost their smell or taste. This is particularly relevant because conditions such as parosmia and phantosmia may follow different trajectories.”

Early in the global COVID-19 pandemic, a 2020 systematic review and meta-analysis of more than 38,000 people with the virus found an estimated 43% experienced smell dysfunction and 45% taste dysfunction. Smell dysfunction became less common with later COVID variants, with a 2023 study finding a global prevalence of 3.7%.

While most people recover, a 2025 review of studies examining persistent symptoms after COVID-19 estimated that about 7% of participants experienced loss of smell three years after infection.

Who’s behind this story?

Lisa Lock

BA art history, MA material culture. Former museum editor, paramedic, and transplant coordinator. Editing for Science X since 2021.

Full profile →

Andrew Zinin

Master’s in physics with research experience. Long-time science news enthusiast. Plays key role in Science X’s editorial success.

Full profile →