A rapid saliva test to assess protection against disease and monitor vaccination in low-middle income countries
Lead Research Organisation:
University of Birmingham
Department Name: Institute of Immunology & Immunotherapy
Abstract
Live saving childhood vaccinations fail to reach ~25 million children worldwide. As a result of the COVID-19 pandemic, many people across the world have missed out on essential vaccines, increasing those at risk of serious disease. Tetanus is a bacterial infection with a high death rate but is preventable with vaccination. Tetanus is one of the key vaccines given routinely but the amount of people receiving this vaccine has slipped back to lower levels seen many years ago. Eliminating tetanus has been an aim for over 20 years. This has been achieved in many countries but in low-middle income countries this disease is still a problem and continues to cause unnecessary deaths every year.
It is important to monitor vaccination and understand how many people are protected against disease, but this can be challenging to do directly. Having information on immunity (protection from disease) is helpful to understand how well vaccination plans are working and help find individuals who are unprotected and need vaccination. However, testing immunity currently requires blood samples. Testing immunity in blood can be expensive and some countries are unable to do it. Also, not everyone wishes to have blood taken and taking blood from children is not desirable.
We will develop a low-cost test that enables immunity to be tested easily, quickly, and without taking blood. The test uses saliva and is a lateral flow test, a type of test which is now well known to the public. The test shows if a person is/is not protected against tetanus within 15 minutes. If a person is unprotected against tetanus, they are also likely missing protection against other serious diseases and have not received all recommended vaccinations. The test can be used anywhere (outreach, community, clinic, hospital) and can improve access to immunity testing for those who currently are unable to do so.
In this project we will develop our saliva test with help from an expert company. We will spend time trying various materials and ways to build the test to get the best invention. We are aiming to use as little plastic as possible in our test. We will also find out the easiest way to collect saliva to run the test. Then we will run lots of saliva samples on our test in a laboratory to check how well the test works. If the test works as well, it will then be sent to be included in a study in Malawi (a low-income country in Africa). In this study, we will see how well our test works in real-life and find out how suitable local people find the test. If successful, after the project we intend to try out the test in other countries to measure immunity among different communities, to improve vaccination monitoring and planning.
It is important to monitor vaccination and understand how many people are protected against disease, but this can be challenging to do directly. Having information on immunity (protection from disease) is helpful to understand how well vaccination plans are working and help find individuals who are unprotected and need vaccination. However, testing immunity currently requires blood samples. Testing immunity in blood can be expensive and some countries are unable to do it. Also, not everyone wishes to have blood taken and taking blood from children is not desirable.
We will develop a low-cost test that enables immunity to be tested easily, quickly, and without taking blood. The test uses saliva and is a lateral flow test, a type of test which is now well known to the public. The test shows if a person is/is not protected against tetanus within 15 minutes. If a person is unprotected against tetanus, they are also likely missing protection against other serious diseases and have not received all recommended vaccinations. The test can be used anywhere (outreach, community, clinic, hospital) and can improve access to immunity testing for those who currently are unable to do so.
In this project we will develop our saliva test with help from an expert company. We will spend time trying various materials and ways to build the test to get the best invention. We are aiming to use as little plastic as possible in our test. We will also find out the easiest way to collect saliva to run the test. Then we will run lots of saliva samples on our test in a laboratory to check how well the test works. If the test works as well, it will then be sent to be included in a study in Malawi (a low-income country in Africa). In this study, we will see how well our test works in real-life and find out how suitable local people find the test. If successful, after the project we intend to try out the test in other countries to measure immunity among different communities, to improve vaccination monitoring and planning.
Technical Summary
Routine immunisation fails to reach ~25 million children worldwide. Global coverage of diphtheria-tetanus toxoid-pertussis vaccine is estimated to be at a 15-year low, disrupting disease elimination goals. Despite a general decline in global tetanus, this disease continues to cause unnecessary deaths in low-middle income countries. To be able to appraise and inform local vaccine policies, it is essential to accurately monitor immunisation and identify gaps in immunity. However, monitoring is currently reliant on report/surveys and indirectly via vaccine doses distributed, susceptible to inaccuracies and bias. Antibody data could inform statistics and help measure the success, or not, of vaccination strategies but also help identify those who have missed out on immunity to guide who does/does not need immunisation. However, antibody testing requires blood samples, which is costly and not accessible in many countries. Further, blood sampling is not always acceptable to individuals nor is taking blood desirable in children. To overcome this, we will develop a rapid and simple non-invasive saliva lateral flow test that measures antibodies against tetanus and provides a yes/no result within 15 minutes on an individual's protective status, in any setting. Tetanus vaccination features in all combined immunisations alongside other serious diseases. If an individual lacks immunity against tetanus, they likely also lack protection against other diseases. Our test therefore not only measures tetanus immunity but can act as a broader marker of gaps in immunity/routine immunisation delivery. We will develop and optimise our saliva test, utilising an industry expert. We will perform retrospective clinical validation in the laboratory using bio-banked samples and evaluate the technical performance of the test. It will then be evaluated in a pilot prospective study in Malawi to assess accuracy, feasibility and acceptability in a representative target setting and population.