Antibody testing for travel
Lower costs and convenience
A proposed user model

The impact of the COVID-19 pandemic has been felt across the globe. Governments across the world during 2020 and into 2021 have quite rightly sought to minimise the loss of life through lockdowns of various types. This has had the desired effect and has reduced infection rates and mortality. From the start of 2021 large-scale roll-out of vaccines which is now signalled the possible return to normality at least for some parts of the World.

However, a great deal of uncertainty remains, for example how COVID-19 will develop, and we have seen mutations with the emergence of the Brazil, South African, Kent and Delta variants. The real risk is that one of these variants impact on the immunity inferred by either previous infection or by vaccines.

Travellers freely moving around after the covid-19 pandemic

Vaccines and their continued development will play a critical role. The development and their subsequent roll-out has been highly impressive, however, testing will also need to play a key role.  In my view this should be a combination of point of care antigen/PCR testing and neutralising antibody testing. This will provide a pragmatic and cost-effective solution and allow us to get back to a degree of normality.

In a series of blog posts Abingdon Health assesses how antibody testing plays a vital role for helping limit risks and making more informed decisions about COVID safety. This article focuses on travel.

Antibody testing for travel – Safer, cheaper and more convenient

Abc-19 rapid COVID antibody test using a blood sample

Whether for work or leisure we need to minimise disruption in the travel market, in particular aviation.

Proof of vaccination or negative test results prior to travel are the preferred solutions. Although UK travel rules are constantly under review.

Irrespective of whether governments, businesses or individuals pay for testing, there are concerns however on the cost of testing and the practicalities of maintaining this for the foreseeable future. There are real logistical challenges; and it is costly.

Testing at home or when abroad prior to travel also does not take away all the risk. For example, what about picking up the infection in the period between testing and arriving at the airport?

Also, does someone produced an immune response following vaccination or infection? There needs to be an understanding on the level of risk. Which is where IgG antibody tests have a vital role to play.

The effective role of neutralising antibody testing

Evidence is building regarding the importance of neutralising antibodies (antibodies that neutralise the virus’ ability to penetrate and infect human cells) in predicting immunity. In May-21 in Italy’s ISS national health institute published research on the study of 162 patients with symptomatic coronavirus neutralising antibody titers progressively drop after 5–8 weeks but are still detectable up to 8 months in the majority of recovered patients regardless of age or co-morbidities, with IgG to spike antigens providing the best correlate of neutralisation.

In the New England Medical Journal in April 2021 Rose (National Institute of Allergy and Infectious Diseases) et al published interim results from a phase 3 trial of the Moderna mRNA-1273 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine indicated 94% efficacy in preventing coronavirus disease 2019 (Covid-19) indicating by the persistence of neutralizing antibodies through 6 Months after the Second Dose. A person’s levels of neutralising antibodies following covid-19 vaccination or natural infection could help predict their level of immune protection, the study suggested.

As reported in the New Scientist in May 2021 David Khoury at the University of New South Wales in Sydney, Australia, and colleagues analysed data from seven covid-19 vaccine studies and one study of people who had been infected with the coronavirus and recovered. The researchers modelled the relationship between neutralising antibody levels and protection from disease and found that neutralising antibody levels were highly predictive of immune protection.

More recent research highlighted immuno-compromised individuals generate lower levels of antibodies compared with healthier people following two vaccine doses1, and there are variations in vaccine-response between males and females2. A further study highlighted different responses in patient cohorts when comparing the Moderna and Pfizer-BioNTech vaccines3, with one study noting antibody levels start to reduce at around 2-3 months4.

This all points to providing a solution that can help understand someone’s level of risk. If someone knows they have no IgG antibodies, they are more likely modify their behaviour and take less risks. Also, they are more likely to seek medical advice.

Lower costs and convenience with antibody testing – a worked example

female airline passenger in COVID mask

COVID-19 antibody tests help to determine risk levels, but as less testing is required there cost benefits too.

If we look at an individual traveller “Emma” who flies once a month (return) for a 3-month period. Assuming she is fully vaccinated and depending on her destination country, Emma could require testing in the UK (let’s assume one PCR test upon return to the UK (£60). In addition, she may require a PCR test (£60) for departure from the UK. For one return journey, this would be a cost of £120 for Emma, and over a 3-month period, on the basis of three return flights, a cost of £360.

Comparatively, using a neutralising antibody test Emma may just require one test which could provide a three-month antibody status certificate and cover all of these flights in that period; at a cost of say, £20.

For Emma, the benefit of this is not only cost, but also convenience as one test provides a result for three months, rather than the hassle of regular testing. In addition, this test result can also be used for a range of other uses, including; going to work; to a conference or to the theatre.

More importantly Emma will be more aware her antibody status and make a decision whether she is happy to fly or not.

If you consider 140 passengers on an A320 airliner, the numbers soon add up. Just on one return flight alone, based on the above example the cost would be £16,800 if PCR testing is used. However, antibody testing could reduce this significantly. Asking passengers to pay £60 for testing for a return journey need to be seen in the context of airline revenue per seat on a return journey of around £120 (based on pre-pandemic EasyJet 2019 financial results). This regressive tax can be significantly reduced by the introduction of neutralising antibody testing that allows a proportion of the passengers to only test once rather than multiple times on each trip. In turn, the reduction in the cost of testing will reduce the cost of flying and should support our travel sector to get back on its feet.

A proposed model: a simple COVID-19 testing solution for travel

AbC-19 rapid antibody test certificate app

Starting with an IgG rapid antibody test – if there are positive neutralising antibodies present – then an antibody status certificate could be provided to be used for travel. The tests can be administered by professionals in pharmacies, workplaces by occupational health workers or in other settings by trained lay people.

Lateral flow antibody testing is easy to administer. A blood finger prick test and takes only 20 minutes to get a result. No large laboratory instrumentation is needed. If needed the result could be recorded on a smartphone app and a QR code issued if required that can be used for a time limited period (e.g. 3-months) for multiple purposes. It is simple, accurate, cost-effective and connected.

In the case there are no neutralising antibodies present – the person would still need to perform antigen and/or PCR testing as set out above to determine their suitability to travel.

In essence, an integrated antigen/PCR/antibody test approach that is easy to administer and is a cost-effective means to travel.

In summary

Antibody testing has a crucial role to play and can support getting people travelling on planes in an efficient, safe and economic way. We have made dramatic strides in dealing with COVID-19 through the roll-out of vaccines, lockdowns, use of PPE and testing regimes. Challenges remain and travel is one sector of the economy that we need to fully open up. In order to do so, we need to provide cost-effective, simple solutions that allow people to travel for work and holidays whilst at the same time ensuring we minimise the risk of COVID-19 infection.

The answer lies in an integrated approach, whether  it’s the combination of vaccines, PPE and testing and within testing the combination of the tools that we have available; antigen, PCR and antibody testing.

The article above was authored by Chris Yates, CEO at Abingdon Health.