Coronavirus has given us a new vocabulary. "Social distancing", "self-isolation", "community spread" and "flattening the curve" slip easily into our conversations, and on the fringe, "immunity passports", something that might change the way we travel.
The immunity passport is a document that says the bearer is free from coronavirus. They've been tested for antibodies to establish whether they've had the disease, even if they're asymptomatic. If the test came back positive for antibodies, they would have taken a separate viral test to find out whether the infection is still active.
The impetus for immunity passports comes from governments looking for a way to confirm who among its citizens have recovered from coronavirus – Germany and the UK in particular. In the words of UK Health Secretary Matt Hancock, "These antibody tests offer the hope that people who think they have had the disease will know they're immune and can get back to life as much as possible".
An immunity passport presupposes you can't get coronavirus a second time, and on that the medical jury is still out. A Chinese study found that several patients who had recovered from COVID-19 subsequently tested positive for SARS-CoV-2, the virus strain that causes COVID-19. Symptoms in all those patients were milder than in the initial phase of the disease, which could suggest a relapse rather than a fresh COVID-19 infection. It's too early to tell yet whether it might be possible to suffer a full-blown case of the disease months or even years after the initial infection.
While the immunity passport is seen primarily as a way to get the wheels of commerce, industry and education turning safely again, it's also being touted as a useful tool that might help get the travel industry back on its feet, allowing travellers with immunity passports to travel more freely, and more widely. An airline might require an immunity passport before allowing passengers to board a flight, or some countries might require it as a condition of admission. And anything that acts as a catalyst to re-start the travel industry will be welcomed. Tourism is the world's biggest employer after agriculture, a $61 billion industry in Australia that employs 5.2 per cent of the country's workforce.
Is an immunity passport a realistic possibility for travellers?
The world already has another "immunity passport" – the orange or yellow booklet that travellers are required to carry as proof of vaccination against yellow fever when returning from visits to countries where the disease is found.
Yellow fever is a haemorrhagic viral disease transmitted by infected Aedes and Haemogogus species of mosquitos. Symptoms include fever, headache, muscle pain, nausea, vomiting and fatigue. Although only a small percentage of those who contract the virus will develop severe symptoms, approximately half of those die within 7 to 10 days. The name comes from the jaundice that afflicts many of its victims.
Yellow fever infects around 200,000 every year and causes 30,000 deaths, but it's easily avoided. A safe and effective yellow fever vaccine has been available for more than 80 years. Just one yellow fever vaccination gives life-long protection against the disease.
Yellow fever is found in tropical and subtropical areas of Africa, in a triangle formed by Angola and north as far as Mauritania in the west and Sudan in the east. In South America, yellow fever is present in 14 countries between Panama in the north and Argentina in the south. That's the reason incoming passengers to Australia are asked whether they have been in South America or Africa when they pass through the SmartGate using their ePassport.
One fact that sets yellow fever apart from coronavirus is the existence of the yellow fever vaccine. That vaccine underpins the authority of the yellow/orange International Vaccination booklet for travellers. For coronavirus there is no vaccine at the moment, and virologists and other medical experts suggest there won't be one for at least a year.
For a coronavirus immunity passport to be worth anything more than a scrap of paper it would need to be constantly updated with tests to detect the presence of antibodies. However with faster testing for coronavirus antibodies on the horizon – Scotland's Quotien diagnostics lab claims its screening machine can produce results in 35 minutes, Australia's Cellmid claims results in half that time for its coronavirus test kit – constant testing might become a minor inconvenience, and a price travellers would be happy to pay in exchange for freedom to travel.