Debunking points in docs' open letter

Professor Ooi Eng Eong, an expert on emerging infectious diseases at Duke-NUS Medical School, and Dr Kenneth Lyen, a paediatrician in private practice, debunked some of the points raised in a letter by 12 doctors about why children should not be given messenger RNA (mRNA) vaccines for Covid-19.

• The letter referred to an article by authors from three educational institutions in the United States - Whitehead Institute for Biomedical Research, Harvard University and Massachusetts Institute of Technology. The article was published last year in the Proceedings of the National Academy of Sciences of the United States of America scientific journal.

The letter noted that "mRNA themselves are very fragile in the human body and are easily attacked by ribonucleases that are distributed very widely in our body".

It also said: "Reverse transcriptase, which converts RNA to DNA, is very troubling. It is not naturally found in our body but becomes readily available if you are very sick with a chronic virus, like hepatitis B."

Prof Ooi said that if that statement were true, "persons living with HIV and hepatitis B would have their entire genome scrambled by the virus".

"Whole human genome sequencing, which is now increasingly common, would have discovered dengue and other RNA virus genome being incorporated into the DNA of these persons. These have never happened," he said.

Dr Lyen added: "The vaccine mRNA degrades within a short period of time, and the integration risk is considered negligible."

• The letter stated that "mRNA vaccines do not stop adults from transmitting Covid-19 variants of concern. We can assume that this will also be the case with children".

Prof Ooi said several studies have consistently found that mRNA vaccination reduces the rate of transmission. The same should apply to children.

Dr Lyen said: "No vaccine is 100 per cent protective. Therefore, some vaccinated individuals can still catch Covid-19, and spread it to others."

If both adults and children are protected against Covid-19, they are less likely to catch it and therefore the virus will not replicate in the body. "If there is no replication, there is no chance of mutations," he said.

• The letter said "it is not very wise to try on Singaporean children novel mRNA technology when they do not really need it and it does not effectively stop them from becoming vectors." It also said: "The good news is that children are doing amazingly well, without any Covid-19 vaccines."

Prof Ooi said vaccines "are not being tried in children". They are licensed for use in children after clinical trials have proven them to be safe.

Dr Lyen said: "While children may not be so seriously affected, in that they do not usually require intensive care, they can still fall quite seriously ill. The statement also overlooks another important reason for vaccination, and that is to prevent spread to other members of the family and to other people in contact with them."

• The letter said killed-virus technology has been around for decades and has a very long and safe track record, but mRNA's long-term side effects are unknown and unstudied.

Prof Ooi disputed this. While killed-virus vaccines are an older technology, such vaccines have "been associated with development of severe disease in those vaccinated", he said.

Although Singapore has bought, and received, the more traditional Sinovac vaccine, it has not been approved for use here as information on its safety and effectiveness has not been sufficient for the Health Sciences Authority, the regulator.

• The letter claimed there was no evidence that mRNA vaccines are safe in the longer term of 10 to 20 years.

Dr Lyen said: "If the risk of not vaccinating and getting Covid-19 results in severe long-term illness and even death, then one should vaccinate. Medical science progresses at incredible speed, so we should not worry about what happens 10 to 20 years later. We will deal with future problems if and when they arise."

Added Prof Ooi: "There is absolutely no evidence to support the notion that there are vaccines that can cause problems 10 to 20 years after vaccination. This is a myth."

Salma Khalik

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A version of this article appeared in the print edition of The Straits Times on May 22, 2021, with the headline Debunking points in docs' open letter. Subscribe