SINGAPORE - A senior infectious diseases specialist, Associate Professor David Lye, has spoken up against misinformation being spread about Covid-19 vaccines by doctors, among others.

In a Facebook post on Monday (June 7) titled "Why fake science and anti-vaccine groups are dangerous in a pandemic", the clinician-researcher at the National Centre for Infectious Diseases (NCID) said he needs to correct certain messages and petitions doing the rounds, which have caused him to have sleepless nights.

Some of these were from a group of doctors including a Dr Paul I.W. Yang, and a Dr Oon Chong Jin, a private cancer specialist, he said.

"Doctors are well respected in our society. Hence their advice may influence the public to avoid Covid vaccination. We should be upset when these doctors quote dubious international experts and research potentially misleading the public," he said.

Among other things, Prof Lye was referring to:

• An open letter by 12 doctors last month, later retracted by 11 of them, urging the Government to give children here the China-made vaccine, Sinovac, as it uses the traditional killed vaccine technology "proven to be safe", and not mRNA vaccines Pfizer-BioNTech and Moderna. They claimed that it wasn't known what side effects might surface 10 to 20 years down the road from these vaccines.

Currently, Singapore's public vaccination programme uses only Pfizer and Moderna vaccines. Sinovac, which has been approved by the World Health Organisation (WHO) under its Emergency Use Listing, will only be available at some private clinics here under a Special Access Route.

•  Comments from Dr Oon, who had been involved in testing the hepatitis B vaccine here more than 30 years ago, on Mount Elizabeth Medical Centre's website and in various chat groups. Dr Oon claimed that the Pfizer vaccine "is useless now and obsolete in the presence of mutations". He had promoted the use of Sinovac for everyone, including children, saying it could protect against the B1617 variants which had ravaged India. He claimed that the Pfizer and Moderna mRNA vaccines could not do this.
• An online petition by "Citizens Against Covid-19" on June 5 that has garnered more than 1,800 signatures saying those under 20 years should not be vaccinated as "the mortality rate for this age group is statistically zero". The petition also calls on a nationwide Outpatient Home Treatment Plan, which it claims was developed by international critical care doctors, where general practitioners provide the cheap antiviral drug ivermectin as treatment and prevention. They said the drug "destroys all coronaviruses including its mutants".

Prof Lye said all those claims are wrong.

On vaccinating the young, he noted that while they don't usually have severe Covid-19 infections unless they have health problems, they carry as much virus as adults if infected, and can infect adults with poor immunity and older adults, who may become sick.

A study in Britain showed that Pfizer and another vaccine by AstraZeneca reduced household transmission by 50 to 60 per cent. "These doctors claimed that mRNA vaccines do not reduce transmission," he noted.

The mRNA vaccines are among the most effective vaccines for Covid-19, he said. They reduce symptomatic Covid-19 by 95 per cent, reduce hospitalisation for the severe form of the disease by more than 90 per cent, and prevent transmission by more than 60 per cent.

There is a wealth of data from the United States, Britain and and Israel on their safety, he said. "Importantly, mRNA vaccines are effective against United Kingdom's B117 (93 per cent), South African B1351 (75-90 per cent) and (India's) B1617.2 (88 per cent) variants.

"There is hardly any data on Sinovac against the variants. Laboratory studies showed that Sinovac may not work well in Brazilian B1128 and South African B1351 variants."

He said: "Although these doctors claimed Sinovac is superior to mRNA vaccines against variants, there is little data to confirm it is effective for B1617.2, and there is data to suggest it is less effective against other variants."

As to claims that mRNA vaccines were developed in a rush, Prof Lye said all Covid-19 vaccines were developed rapidly, and "in fact, Sinovac and Sinopharm were approved in China before the trials were completed".

"Singapore and China have strong relationships. There is no reason for Singapore not to approve Sinovac. But approval requires data judged to be adequate," he said.

The Health Sciences Authority (HSA) is still awaiting a reply from Sinovac on its queries, he pointed out. "With the latest update on criteria for mRNA vaccines, there are very few reasons why a person cannot take mRNA vaccines. These doctors are pressuring HSA to ignore rigorous review process."

He also debunked the oft-cited belief that Sinovac is safe because it uses traditional methods: "Even though inactivated whole virus vaccine is an old technology, it is not harmless and we still need to watch out for side effects. In the 1960s, two inactivated vaccines for measles and respiratory syncytial virus led to more severe disease, and were withdrawn."

He added that hepatitis B vaccine, which Dr Oon had championed, is not a killed whole virus vaccine like Sinovac either.

He noted how these doctors quoted a study that showed how RNA from the Covid-19-causing virus could be integrated into human cells and said: "While this has been quickly debunked by scientists as an artefact of the laboratory methods, these doctors failed to understand that mRNA from vaccines do not last for more than two days in our body and are different from viral RNA from Covid infection."

He also criticised calls by some doctors to use ivermectin, which is used to treat parasites, and fluvoxamine, an anti-depressant, instead of vaccination.

Ivermectin has not been proven to be effective in Covid-19, he said, adding that "very few properly conducted clinical trials have been published".

"Among others, evidence cited for ivermectin in Covid included the faked database company called Surgisphere which led to two journal retractions from the prestigious New England Journal of Medicine and Lancet in 2020," he said.

In fact a local study at a dormitory, led by Professor Paul Tambyah, a senior infectious diseases consultant at the National University Hospital (NUH), found ivermectin not effective in preventing Covid-19.

"I urge the Singapore public to be aware and alert of fake science on social media," said Dr Lye, who had made headlines last month when he asked people to form and stick to their their own social bubbles to keep their families safe. "Anti-vaccine groups from Singapore and overseas are highly active. We must win this war against the virus. Effective Covid vaccines are a part of our solution."

Dr Benjamin Seet, a deputy CEO at the National Healthcare Group who chaired the panel that picked the vaccines for Singapore including Pfizer, Moderna and Sinovac, applauded Prof Lye's comments in a LinkedIn post.

He said: "Doctors are taught that when they are unable to do good, they should do no harm. It is sad that in this age where reliable information is so readily accessible, that some choose to become purveyors of mistruths, poor science and misguided advice. I'm glad that David, my colleague at NCID, has stood up against this. We should draw a line when this has obviously been crossed."

Asked for his comment, Dr Yang, a general practitioner who had drafted the open letter signed by a dozen doctors, would only say that Prof Lye "should trust your elders", referring to Dr Oon, who could not be reached.

Over the weekend, several political leaders reiterated the need to make decisions based on science.

Senior Minister Teo Chee Hean, who is also the Coordinating Minister for National Security, posted on Facebook on June 5 following a chat with Members of Parliament and volunteers on "all the noise suddenly being created" on social media.

He said: "We concluded that we should focus on the science and take the advice of our medical experts, and decide what is the appropriate action based on our public health needs in Singapore."

On Monday, Speaker of Parliament Tan Chuan-Jin also posted on Facebook: "In the midst of a major health crisis, there are those who are seeking to mislead and misinform for political reasons because it helps to erode trust and confidence."

He said the government has sought to keep people informed. "We need everyone on board... Please do support. It'd help by not circulating misinformation."

This article was first published in The Straits Times. Permission required for reproduction.