• While lockdown measures appear to have been effective in curbing the spread of the new coronavirus, experts say loosening restrictions too much before a vaccine is available may lead to a resurgence of cases.
  • A new study of China led by researchers at Hong Kong University concluded that there was still a “substantial risk” of new infections, particularly from travelers, and that the virus needed to be closely monitored to prevent another outbreak.
  • “Although control policies such as physical distancing and behavioral change are likely to be maintained for some time, proactively striking a balance between resuming economic activities and keeping the reproductive number below one is likely to be the best strategy until effective vaccines become widely available,” said the study’s lead researcher, Joseph Wu.
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Lockdown measures in China were effective in curbing the “first wave” of the novel coronavirus’ spread, a new study led by researchers at Hong Kong University has concluded. But experts warn that loosening restrictions too much before a vaccine is available may lead to a resurgence of cases.

The study, published in the Lancet medical journal on Wednesday, was first reported on by The Guardian. The research was based on modeling of the virus’ spread in China, which appears to have been contained as the country has not reported any new domestic cases since March 19.

“The first wave of COVID-19 outside of Hubei has abated because of aggressive non-pharmaceutical interventions,” the study found.

The research concluded that China had been able to greatly reduce the virus’ reproduction number – meaning, the number of people on average who one person can infect – from two or three to just under one.

But the study warned there was still a "substantial risk" of new infections, particularly from travelers. It stressed that the virus' spread needed to be closely monitored to prevent another outbreak, or "second wave" of the disease, and achieve "an optimal balance between health and economic protection."

"Although control policies such as physical distancing and behavioral change are likely to be maintained for some time, proactively striking a balance between resuming economic activities and keeping the reproductive number below one is likely to be the best strategy until effective vaccines become widely available," said Joseph Wu, who leads the infectious-disease-modeling research at the Hong Kong University's School of Public Health and co-led the study.

The virus has infected over 1.5 million people worldwide and killed more than 88,000. China, once the epicenter of the disease, has reported more than 82,000 cases and 3,337 deaths.

Rebecca Cairns reported for Insider that more than 40 research teams were developing a vaccine for COVID-19. Though producing an effective and safe vaccine can normally take five to 10 years, research can be expedited during times of outbreak with increased funding.

"Given the current severity of the crisis, there are efforts to fast-track a vaccine for COVID-19 in as little as 12 to 18 months," Dr. Abe Malkin, the founder and medical director of Concierge MD in Los Angeles, told Cairns.