SINGAPORE - As excitement soars over the promise of Covid-19 vaccines, experts have warned that even the best vaccine will be no panacea on its own.
Ultimately, the key to beating the virus can only be through a combination of a good vaccine, treatment that reduces severe illness and death, and individual responsibility in reducing the spread of the virus.
Professor Ooi Eng Eong, deputy director of Duke-NUS' Emerging Infectious Diseases Programme, said: "At the end of the day, the control of Covid isn't going to rely on vaccines, it isn't going to rely on drugs, it isn't going to rely on measures like social distancing alone.
"It's probably a combination of everything that we can throw at this virus."
He added: "If you put all of this together, we can, at least try and keep this problem at bay and go back to as much of our normal lives as we can."
Prof Ooi was one of three experts who spoke at a Straits Times Covid-19 webinar on Thursday (July 23), looking at six months of the disease in Singapore, after the first case was reported on Jan 23.
The focus of the session, which attracted over 1,000 participants, was lessons learnt and how these would shape the way forward in tackling Covid-19.
Professor Dale Fisher, a senior infectious diseases expert at the National University Hospital who was also on the panel of experts, said there has been a lot of hype recently about positive developments in vaccine research.
He said. "Every time anyone has got some news, they know that this will affect their share price, their pre-sales, their funding ... and all of us grasp that information and get so excited about a vaccine."
First, there is not going to be a commercially viable vaccine this year. When a vaccine does become available, there won't immediately be enough vaccines for everyone. And also, it is unlikely that any vaccine would fully protect everyone, he said.
Prof Ooi, who has a team working on a vaccine, said he would be satisfied if it was 50-75 per cent effective.
This means that not everyone who gets vaccinated is protected against Covid-19.
A 50 per cent efficacy means only half of the people are actually protected and the rest could still get infected.
Still, it would offer a sufficient level of protection, he said.
"Seventy per cent effectiveness is actually very good. You know, even a natural infection would not give you 100 per cent protection from a second infection. Whether Covid gives you lifelong protection or short-lived protection, that's something that's being debated," Prof Ooi said.
"The way the vaccine works is it isn't just at the individual level. So the person who falls into the 70 per cent and is protected against infection, that's great, they won't get it. But actually they go on to protect the others who don't actually develop immunity, and that's this whole concept of herd immunity," he added.
Vaccines generally work better in young healthy people, and less well in those who are older or have underlying medical conditions - but these are the people who tend to get more sick if they get Covid-19.
Prof Ooi said: "If the young people are solidly immune, then they would not pass the virus on to the old people, older people, even if they are not immune or not vaccinated."
But Prof Fisher said that having a vaccine does not spell the end of the Covid-19 pandemic. "Even after the vaccine comes, we're still going to have cases. We're still going to have little clusters. It'll just be a lot easier to manage with the vaccine."
It is equally important to be able to treat patients so that most do not get severely ill or die of the disease.
Prof Ooi agreed that a vaccine is not a magic bullet that would solve the Covid-19 problem.
The situation in the community in Singapore looks promising, said the third speaker, Professor Teo Yik Ying, dean of the NUS Saw Swee Hock School of Public Health.
But while people can now socialise more under phase two of the reopening of the economy, they should still reduce their "risk-taking ventures", he said.
Meeting the same people, such as colleagues or family, for meals is fine. But having meals with different people every time increases the risk of exposure.
He also said the economic impact of the pandemic would vary for the different segments of the population, with some that would be harder hit.
He said: "This inequity is going to increase significantly because there will be some sectors that are now being forcefully kept shut to allow the rest of the economy to function as per normal."