When it comes to the Delta variant, one thing is becoming increasingly certain: The vaccine is still not enough to deal with this variant.
That means Singapore cannot give up the fight against Covid-19, said Professor Leo Yee Sin, Executive Director of the National Center for Infectious Diseases (NCID) Singapore.
“If 2020 is 100% effort, this year we have to give 200% effort because the Delta variant forces us to. We can’t just rely on vaccines,” Ms. Leo Yee Sin said in a reply. Interview with the Straits Times.
In other words, wearing a mask, washing your hands, and staying vigilant are still measures to take even if you’ve been vaccinated against Covid-19.
According to Professor Leo, there are three properties that make the Delta variant more infectious than the original strain. The first is that infected people shed larger amounts of the virus. International studies have shown that the Delta variant can attach more tightly to the human upper respiratory tract, making it more contagious to others. This variant also reduces the incubation period from 5 days to 3 days, meaning it can infect others more quickly.
If the epidemic is not properly controlled, Singapore could face an exponential increase in the number of cases, Professor Leo assessed. “What we have to remember is that this virus can cause a very rapid increase in the number of cases in the community.”
Singapore has seen the number of new cases soar over the past month with large clusters of infections at bus stops, migrant worker dormitories and shopping malls. From February to December 2020, the country had 200 community cases/month, but this number increased to 590 cases from January to August 2021, mainly for the Delta variant.
The number of new community cases in Singapore rose to 1,325 last week, from 723 the previous week.
On September 6, Finance Minister Lawrence Wong announced new measures to slow the spread of the virus and give people more time to get vaccinated. These measures are given by current vaccines that can prevent severe cases but are less effective at preventing infection, especially by the Delta variant.
Singapore’s Health Minister Ong Ye Kung said the vaccine is about 40% effective in preventing cases while the vaccine’s protection can fade after a few months.
Still, Professor Leo said that every percentage increase in national vaccine coverage could translate into “significant benefits” in protecting the population, especially the elderly, against the Delta variant. .
Studies have shown that the Delta variant has a baseline infectivity coefficient (R0) of 5-8, meaning that an infected person can spread the virus to 5-8 other people. This rate is comparable to chickenpox.
In Singapore, the estimated R0 is 1.45. The Delta variant is thought to be twice as infectious as the original strain. That means R0 will increase significantly if the distancing measures are lifted.
In general, unvaccinated people infected with the Delta variant had more severe symptoms than those infected with the original strain. In addition, severe cases are more common in younger people in their 40s and 50s.
The good news is that in Singapore, although unvaccinated people still need oxygen, fewer people have died from this disease. That shows that early detection and timely intervention play an important role. Also, while both vaccinated and unvaccinated people have high viral loads, vaccination helps us recover faster. Viral loads tend to decrease in people who have been vaccinated after about five days, said Professor Matthias Toh, director of the National Epidemiology and Public Health Unit at NCID.
However, Professor Leo emphasized, there is no reason to let go of vigilance against the current epidemic. “A lot of people feel that after vaccination, it’s time to relax. Our message now is: There is no time to be complacent, even after vaccination. We expect behavior. People’s health did not change after they received 2 doses of the vaccine and thought they were “superman”.