This season, flu shots may be less effective due to limitations caused by the COVID-19 pandemic which have impacted data collection, a health expert said on Sunday.

The World Health Organization (WHO) recommends that health care workers and people who are most at risk of developing serious complications from influenza infection be inoculated every year before the influenza season, which typically occurs during autumn and winter, begins.

“We saw quite a big reduction in the labs supplying the genetic sequence data to WHO, and around September last year we saw a 94 percent drop in the genetic sequence data that was reported into the database,” health expert Dr. Beverly Taylor was quoted by the Daily Telegraph as saying.

Taylor works at a pharmaceutical company called Seqirus, a global influenza vaccine company.

“This has had a massive impact in the reporting. We could have reduced the opportunity to identify viruses as they emerge. We certainly have reduced the opportunity to look at which vaccines would give the best overall protection and the best coverage of all the circulating viruses,” the doctor added.

Earlier this month, Reuters reported that flu vaccination may lower the risk for severe illness from the coronavirus, including life-threatening sepsis infections and strokes, citing a report in PLoS One, a peer-reviewed scientific journal.

The researchers studied nearly 75,000 COVID-19 patients, half of whom had received the most recently available flu shot.

They also found fewer patients who had flu shots had to be admitted to intensive care units or visited emergency departments, and fewer had dangerous blood clots in their legs, compared to patients who did not get flu shots.