A passenger on Singapore Airlines flight SQ325 -- the first flight to arrive under the new Vaccinated Travel Lane (VTL) -- is pictured in the baggage hall at Changi Airport in Singapore on 8 September, 2021, as travellers vaccinated against the Covid-19 coronavirus arrive from Frankfurt, Germany and are able enter Singapore without quarantine. (Photo: Roslan RAHMAN/ AFP)

A passenger on Singapore Airlines flight SQ325 -- the first flight to arrive under the new Vaccinated Travel Lane (VTL) -- is pictured in the baggage hall at Changi Airport in Singapore on 8 September, 2021, as travellers vaccinated against the Covid-19 coronavirus arrive from Frankfurt, Germany and are able enter Singapore without quarantine. (Photo: Roslan RAHMAN/ AFP)

The Delta Variant and Border Closures: A Rethink is Overdue

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The highly transmissible Delta variant of the coronavirus should lead to a rethink about border closures in Southeast Asia.

The Delta variant of the coronavirus has become or is fast becoming the dominant variant in Southeast Asian countries. It is already dominant in countries that were successful in containing the spread of earlier strains, and rapidly catching up in those that were not. The high transmissibility of the Delta variant should force a rethink on the methods used in combating its spread in the community. As it becomes dominant, it calls into question the current combination of mobility restrictions at and within borders. In particular, its high transmissibility is eroding the health-protective effects of border closures relative to domestic mobility restrictions, while the economic cost of the former continues to rise with time. A recalibration in Southeast Asia, as seen in Europe and North America, is overdue.

After more than a year and a half since borders were first closed around the world, Southeast Asia remains mostly closed to non-essential travel, unlike in Europe or North America.  A lot of this has to do with the lower vaccination rates in the region. Reaching herd immunity through vaccination may be required before allowing quarantine-free travel for the vaccinated because they still carry some risk of infection, but a much lower risk of developing severe symptoms. Therefore, opening up to vaccinated travellers reduces the risk of them adding strains to already-challenged healthcare systems while achieving herd immunity protects the local community.

Although the vaccination rate is close to or higher than a common minimum threshold of 70 per cent in Singapore, Cambodia and Malaysia, there has been little movement on the opening of borders in these or other Southeast Asian countries. The same stringency has not applied to domestic mobility restrictions, however, which has been trending downwards in most countries despite ongoing community outbreaks. Malaysia has been easing domestic curbs despite consistently having one of the world’s highest infection rates on a population-adjusted basis, while Manila ended a domestic lockdown on the same day in August that daily infections reached a new record high

This seemingly contradictory behaviour is explained by lockdown fatigue and the need to balance health and economy, especially given the dwindling fiscal space in many countries. Once the balance between health and economy is struck, however, there are different combinations of domestic and border restrictions that can produce the desired economic outcome. So far, most of the actions to support the economy has focused on easing domestic restrictions. Border restrictions have hardly featured in the calculus. In fact, because borders must remain mostly closed, the economic imperative has required so much domestic easing that health risks have risen sharply, as evidenced by soaring infection rates. If this lopsided approach was suboptimal before, it is getting unsustainable with the Delta outbreak.

shifting the focus from border to domestic restrictions, for any given health-economy tradeoff, would be beneficial.  Such a shift would better address economic considerations while providing the best opportunity to contain community spread.

Border measures carry a premium only while they keep the Delta or other variants out. In Singapore for instance, the number of imported cases was a multiple of those spreading in the community before Delta; now they are just a small fraction, because of Delta. Since it is difficult to determine from the genetic sequencing alone if new variants are more transmissible, the alarm is raised only when they appear in large case numbers at origin, by which time it is too late for border measures to stop them spreading. When the number of imported cases constitute a small fraction of community ones, the value of border restrictions relative to domestic measures in limiting the spread of a highly transmissible variant starts to fall sharply. This would suggest that shifting the focus from border to domestic restrictions, for any given health-economy tradeoff, would be beneficial. Such a shift would better address economic considerations while providing the best opportunity to contain community spread.

The countries in Europe and North America have recognised this and have moved to progressively open their borders while retaining some domestic protocols and social distancing measures in place to protect the community. It is time that Southeast Asian countries start planning to move in the same direction even as they ramp up vaccination efforts. 

The only countries in Southeast Asia that have started opening their borders to non-essential international travel are Singapore and Thailand. Singapore has opened up to a few countries with low infection and high vaccination rates, some of which have reciprocated. Thailand has employed the sandbox or ‘micro herd immunity’ approach, in the resort islands of Phuket and Koh Samui, to open up unilaterally to a larger number of countries. The impact so far has been muted due to hesitancy and complex procedures, both of which are improving with time. Singapore expects to open up to more countries soon, while more parts of Thailand may open by November 2021.

If these moves succeed in attracting large numbers of travellers without compromising domestic health conditions, then it may have demonstration effects that set off domino-type effects in the region. Cambodia has announced plans to reopen before year-end, while Phu Quoc island in Vietnam may open to vaccinated tourists in November. When the reopening spreads further, then harmonisation followed by mutual recognition of standards and protocols should be pursued to increase both intra and extra-regional flows. In this way, unilateral opening and bilateral travel bubbles can lead to broader, multilateral outcomes for Southeast Asia.

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