In what appears to be a world-first, Hong Kong has said the next step in reopening is allowing entry based on positive antibody results.
Hong Kong’s Strict COVID Regulations
Hong Kong has some of the strictest COVID-19 regulations in the world. Virtually no travelers to Hong Kong are permitted unless they are from Australia/New Zealand. Of those, permitted entry (including permanent residents and citizens) cannot have visited any other countries within the last 21 days, and still must satisfy quarantine requirements in an approved hotel for 14 days following a negative test result with an additional COVID-19 test they must pass on the 19th day following their arrival.
Transit customers are approved so long as the transit window is shorter than 24 hours, is on a unified itinerary, meets the entry requirements for their destination, are not connecting to the Chinese Mainland, and do not leave the airport.
There is no waiver for vaccinated travelers.
The city-state has previously attempted a travel bubble with Singapore though this was discontinued. Hong Kong COVID numbers have remained relatively low compared to the global figures, however, it’s been at a dire cost to the economy which Lam is anxious to restart.
Chief Executive Lam Aims to Reopen
According to reports, Hong Kong leader, Carrie Lam, aims to add a simple pinprick blood test to check for antibodies.
“Health authorities may take blood samples for coronavirus antibody testing from arrivals at Hong Kong’s international airport under a proposal aimed at shutting out dangerous new variants, as the city tries to stave off a potential fifth wave of infections.” – South China Morning Post
One of the variants of concern in specific is the United Kingdom variant which has a higher transmission rate than others. The Department of Health currently oversees testing at Chep Lok International Airport on behalf of the Hong Kong government.
Without a doubt, social distancing rules would remain in effect even with the new entry criteria as would masks until Hong Kong’s population can complete mass testing and inoculation.
Antibody Tests Make The Most Sense
In a prior version of this post, I asserted that this would be in lieu of other screening methods as the only entry requirement. This was incorrect, however, it could lead to this as the preferred method going forward, if not in Hong Kong, in other places. I have left the rest of the post as it is because the sentiment remains accurate.
There remain a number of unknown factors when counting those who have a possible immunity or antibodies that prevent susceptibility to COVID-19. The first group of known factors is the amount of recovered COVID-19 survivors which changes every day but is approximately 172M at the time of writing. About 480M have also been fully vaccinated as well – both of those groups are known to have antibodies to the virus with the exception of outlier cases.
There have been 2.2bn doses taken, which have been known to provide some level of antibodies even in two-dose vaccines. Further unknowns, however, are underreported cases. Underreported cases include those who had the virus before it was identified as COVID-19, those who never sought treatment for any number of reasons, and those who were asymptomatic. The CDC estimates this number to be as high as 4.3x known cases for the US alone. While I believe this number could be far higher outside the US than this (for example, India is widely thought to be underreported.) There is also an unknown number of people who may have an immunity to the virus that remains unquantifiable.
Of the 7.2bn people estimated to be living on earth, no less than 10% are confirmed to have the antibodies necessary to prevent new infection of the virus but it could be as high as half. This is just one reason why trying to ascertain who should and should not be permitted entry is inaccurate but also a moving target.
Leff, from View From The Wing, points out the difficulty with vaccine passports. A Cleveland Clinic study of more than 52,000 employees has found there’s no point in vaccinating those who have already had the virus. Despite the G-7 committing to one billion vaccinations donated to the developing world, half of which supplied by the US, roll out will take a very long time.
Given this information, it makes far more sense to test for antibodies and reopen, rejecting those who fail to have the antibodies.
It looks at the question of entry into Hong Kong at a fundamental level: Does this person pose a threat to the people of Hong Kong?
There has been speculation as to how long antibodies remain effective, though not significant proof that they “wear off,” at least not yet. But even if antibodies eventually do disappear, the question of entry is one that addresses whether one has the antibodies at that moment. If the answer is yes, the provenance of those antibodies is moot.
This is the only method that asks and acts on COVID-19 infection threats in a complete way. Entering the United States requires a negative COVID-19 result, regardless of COVID-19 vaccination. As commenters have pointed out in the past, infected travelers test negative up to three days after they contract the virus, and those who have recovered may continue to test positive up to 90 days after they have recovered. However, those who have active antibodies are not a risk to others regardless of nucleic acid test results.
Hong Kong is my favorite city in the world, I can’t wait to return. If antibodies were to be the only requirement for entry, the approach seems to be unique, thoughtful, and hopefully effective. It answers the question as to whether someone poses a risk – the only question that should be asked. When the answer is “no” they would be welcomed to the city if the measures are approved. If Hong Kong can prove effective in this regard, hopefully, other destinations will follow the same guidelines.
What do you think? Do you prefer Hong Kong’s approach? Will it be approved?