Better domestic surveillance, not closing borders, is key to containing coronavirus spread

Closing borders will not stop new or future variants from finding their way in but it will stall fragile recoveries and add to economic and social distress
Instead, governments should ramp up domestic protocols ahead of the roll-out of mass vaccination campaigns

Jayant Menon

Published: 8:45am, 6 Feb 2021

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Since Covid-19 was first detected in human beings more than a year ago, it has undergone thousands of mutations. We have largely ignored these because they did not appear to alter transmissibility or virulence.

This changed in late 2020, when a spike in infections in Britain was linked to a variant called B.1.1.7 and another surge in South Africa to a variant called 1.135. There is concern that most of the recent surges around the world could be because of these or other new variants, some of which are still unidentified.

While more transmissible, it is unclear if the new variants can cause reinfection or are more lethal. Evidence is emerging that the South African strain could reinfect those with antibodies from the original strain. The increase in the mortality rate in the UK could be because of the surge overwhelming an already strained health care system, leading to its lower efficacy in preventing death, rather than a more lethal strain.

There is also concern that Covid-19 vaccines could be less efficacious in preventing severe symptoms from the South African strain. All these concerns are real, but it is too early to tell.

Many countries have responded by closing their borders to travellers who have been in countries where the new strains originated or where cases have been reported. With tight border restrictions already in place, an escalation to ban travellers from an increasing number of countries will delay economic recovery.

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Given the costs, can such measures prevent or limit entry of the new strains? The evidence suggests it cannot stop entry and there are better ways to limit its spread.

The main reason it cannot prevent entry has to do with the nature of the identification process. It is difficult to determine from the genetic sequencing alone if the variant is likely to be more transmissible or virulent, and so it needs to show up in cases before this can be determined.

This is why it took until December 14 before UK authorities raised the alarm about a strain discovered in September. By then, the UK strain had already spread to about 50 countries. This number continues to increase because not all countries are able to test with equal efficiency or speed.

These differences in genomic surveillance capacity further highlight the futility of trying to keep the new strains out through selective travel bans.

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If border closures cannot stop the new strains, what should the authorities do? It would be better to concentrate on efficiently implementing existing protocols rather than creating new ones. Applying existing testing, quarantine and tracing measures effectively would provide the best way to limit the importation or spread of the original, new or future strains.

Singapore provides a good example of how this approach can work. Although recent daily imported cases have been in the double digits, with a cumulative total in the thousands, this has not resulted in a direct case of community transmission. The Singapore experience tells us that there is no need to incur additional economic costs by closing borders if existing protocols are faithfully implemented.

Another country praised for its pandemic response is New Zealand, but it had its first case of local transmission in several months recently and it was the South African variant. The fact that it occurred because of a breach in quarantine tells us that no system is perfect and can always be improved.

However, other domestic protocols, including rapid testing and efficient tracing, kicked in to prevent a community outbreak. New Zealand also has tight border restrictions, reminding us that short of total isolation, importation of the virus is almost inevitable. Therefore, the key lesson from the New Zealand experience is that the only workable option is to keep improving implementation of domestic protocols.

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While it is, and has always been, too late to close borders, why do governments insist on doing so? It might be that they want to appear to be responding directly and decisively to the new threat. Acting as if the threat can be repelled at the border itself could be electorally appealing, if somewhat misplaced.

It might also give the impression that any costs are borne by non-residents, although the evidence suggests otherwise. Last, but not least, when the measure inevitably fails, governments can always find a scapegoat and claim to have tried their best rather than admit to having botched their response.

In sum, just as it was with the original strain, closing borders will not stop the new or future variants from finding their way in. What they can do is stall fragile recoveries and add to economic and social distress without any compensating benefit. What we can do is limit the spread of the new variants through better domestic surveillance while we wait for the roll-out of mass vaccination campaigns.

The race is no longer between vaccine roll-out and viral spread, but rather against the emergence of a more resistant strain. Improved domestic surveillance rather than border closures is needed to buy time for the vaccine roll-out, delayed by bureaucracy and nationalism, to finally defeat a rapidly mutating virus.

Jayant Menon is a visiting senior fellow at ISEAS-Yusof Ishak Institute, Singapore, and former lead economist at the Asian Development Bank