TAIPEI (Taiwan News) — As COVID-19 case numbers have stayed below 200 for four straight days and Taiwan's R number has dropped to 0.46, an epidemiologist is calling for a Level 2.5 alert as a transition from Level 3 to Level 2 restrictions for up to two weeks.
During a livestream on Wednesday, National Taiwan University epidemiologist Chen Hsiu-hsi (陳秀熙) said that due to non-pharmaceutical prevention measures (NPI), such as wearing masks and maintaining social distance, Taiwan's R number has dropped to 0.46. He said that the R number over the last two weeks has been less than one, indicating the country's epidemic prevention measures have been effective.
When used in the context of the pandemic, R is short for the basic reproduction number (R0). In the absence of herd immunity, R measures the average number of persons one individual with the virus can infect. The larger the R number, the more difficult it is to control community transmission.
Chen argued that due to this rapid progress, Taiwan could loosen some of its Level 3 restrictions soon. However, instead of directly dropping to Level 2, he suggested first entering an intermediary phase of Level 2.5 for at least one to two weeks.
He recommended four criteria must be met before Level 3 can be dropped to Level 2, the first two of which have already have been achieved. First, 70 percent of all medical staff have been vaccinated, which can reduce the rate of hospital infections and possible super-spreaders from household infections.
Second, masking and social distancing have been observed by over 90 percent of the population and now only need to be maintained. Of the two prerequisites not yet achieved, the first is that everyone in long-term care facilities and the elderly who live at home must be fully vaccinated.
The second is to promote testing at companies, communities, local clinics, and households. Chen said that a characteristic of the Alpha variant is that it spreads through "silent transmission" and continues to form small cluster infections.
If these clusters can be quickly identified through the screening strategies recommended, the risk of the recurrence of community transmission can be reduced. Chen pointed out that no matter how fast the vaccine is administered, it will take one to two weeks.
Therefore, he argued that a Level 2.5 buffer is needed between the Level 3 and Level 2 alerts. Chen said that this Level 2.5 phase needs at least one to two weeks of observation as some epidemic prevention measures are gradually relaxed.
Experts can determine whether the measures still in place can prevent small cluster infections from breaking out during this buffer period. Based on the experience of Israel, the U.S., and Canada, Chen asserted that vaccination rates must reach 20 to 50 percent to enable public health measures to control a local outbreak.