New virus SARS-CoV-3 may appear

At the Asean Digital Public Health Ministerial Meeting, Professor Wang Linfa from Duke-NUS Emerging Infectious Diseases programme said the phenomenon is known as reverse-zoonosis, when the virus is transmitted from humans to animals.

Most scientists believe that the ancestor of the new coronavirus originated in a bat found in Asia, and then jumped to an “animal X,” possibly a pangolin or a civet tree, and then to humans at a seafood market in Wuhan, China.

"Next, as we know, the outbreak spread widely in the human population. But what surprised us was how easily the virus was transmitted from humans back to animals," Professor Wang explained.

So far, the world has recorded a few cases of pets being infected with nCoV from their owners, but the opposite has not been confirmed. "It would be worrying if humans could transmit Covid-19 to new hosts, such as bats in the Americas, which are not natural reservoirs of the virus," Professor Wang said.

According to experts, the situation could have happened as an individual bat ate fruit left by an infected person. The research theory is based on Professor Wang's professional experience in immunology and zoology.

Professor Wang and colleagues successfully cultured the nCoV after it emerged in Wuhan last year, making Singapore the third country after China to do so.

"Bats have a very unique immune system. They can maintain the virus in their bodies without developing the disease. However, the virus still mutates and is transmitted to other animals X, Y, Z. When the mutated virus from those animals infects humans, we will be infected with the virus (temporarily called) SARS-CoV-3 in the future," Mr. Wang explained.

Each time a virus jumps between species, it is forced to undergo major genetic changes to adapt to its new host. The more it spreads, the more it mutates. One of these new strains may become SARS-CoV-3.

A bat was discovered by scientists in a cave near Ely, Nevada, USA. Photo: NY Times

Professor Wang proposed three levels of preparation for each country to respond to this new pandemic.

LevelFirstlybefore the pathogen emerges. Countries need to look at the viruses in different animals, which are traded and consumed frequently. This is difficult to do, because scientists have no criteria for predicting which viruses are likely to jump easily from animals to humans.

Scientists must work with government agencies and international organizations to assess risks and prepare countermeasures to prevent the spread of the virus.

LevelMondayis an early warning. Severe, unusual cases in an intensive care unit or local health facility can be the first sign of a new virus. This has been the case in Wuhan, where doctors admitted many patients with severe pneumonia who tested negative for all known pathogens.

LevelFinalis when the virus starts to spread. The solution now is to develop a vaccine and find a suitable treatment. Experts at Duke-NUS University are researching this issue.

Professor Wang and his colleagues are developing a vaccine specifically for future booster shots that will protect users even if nCoV and coronaviruses in general mutate. They came up with the idea when they discovered that people who had SARS in 2003 who received the Pfizer Covid-19 vaccine produced antibodies that neutralized all mutations of nCoV, such as Delta.

The antibodies also tackle other animal-borne coronaviruses. The vaccine boosted a good response to the SARS virus in mice. Now that there is evidence of efficacy, Wang’s team plans to begin human trials in the near future.

He plans to recruit volunteers who have had SARS in Hong Kong, Guangzhou or Toronto. The aim of the study is to find out the level of immunity in people after being vaccinated with vaccines such as Moderna, Sinovac or AstraZeneca.