A senior official of the World Health Organization (WHO) clarified on Tuesday that her remarks on the rarity of the transmission of the new coronavirus from the asymptomatic carrier was mistaken, Agence France Presse reported.

Maria Van Kerkhove, the World Health Organization's Covid-19 technical lead, had said that on the basis of studies carried on asymptomatic carriers, the transmission from such cases was “very rare.”

"We have a number of reports from countries who are doing very detailed contact tracing. They're following asymptomatic cases, they're following contacts and they're not finding secondary transmission onward. It's very rare," she told a virtual press conference on Monday.

Her remarks went viral on social media sites and spurred reactions from the scientific community.

"Contrary to what the WHO announced, it is not scientifically possible to affirm that asymptomatic carriers of SARS-CoV-2 are not very infectious," professor Gilbert Deray of the Pitie-Salpetriere hospital in Paris said on Twitter.

Liam Smeeth, a clinical epidemiology professor at the London School of Hygiene and Tropical Medicine, said he was "quite surprised" on WHO official’s remark.

"There remains scientific uncertainty, but the asymptomatic infection could be around 30 per cent to 50 per cent of cases. The best scientific studies to date suggest that up to half of cases became infected from asymptomatic or pre-symptomatic people," he said.

After the outpouring of reactions, Van Kerkhove later posted on Twitter a WHO summary on transmission.

"Comprehensive studies on transmission from asymptomatic individuals are difficult to conduct, but the available evidence from contact tracing reported by member states suggests that asymptomatically-infected individuals are much less likely to transmit the virus than those who develop symptoms," it said.

During a discussion retelecasted Tuesday on the WHO's Twitter account, Van Kerkhove noted that she wanted to clarify a misunderstanding.

"I was referring to very few studies, some two or three", and answering a question...I was not stating a policy of WHO," she said.

"I used the phrase 'very rare', and I think that is a misunderstanding to state that asymptomatic transmission globally is very rare. What I was referring to was the subset of studies," she added.

WHO, COVID-19, coronavirus, asymptomatic