The following gives a personal case study of why knowing your COVID-19 antibody status is important for both individuals and the wider society.
The personal example below charts the antibody responses of myself, Dr Chris Hand, and my wife over 25 weeks from first vaccination through second vaccination, and subsequent COVID-19 infection.
Introduction to SARS-CoV-2 antibodies
The advent of vaccines has helped those who have access to vaccination to diminish the effect of the SARS-CoV-2 virus. Antibodies to the SARS-CoV-2 virus are produced after vaccination and after natural infection. The type of antibodies which help to create immunity are known as neutralising antibodies: these are IgG antibodies which interact with the spike protein of the virus and prevent it being able to bind to receptors and enter human cells.1,2 Other types of antibodies exist such as those to nucleocapsid protein but these are of no use in monitoring immunity.3
IgG anti-spike antibodies are the type detected by the AbC-19TM lateral flow device (LFD). Antibodies levels rise after infection or vaccination, generally reaching a peak 14-21 days after exposure and will persist for many months after infection but maybe less so after vaccination therefore requiring booster vaccinations.
Monitoring an individual’s antibody status allows them to make more informed decisions about their health and social interactions. Determining IgG neutralising antibody status is empowering for giving people insight into their immune response post-infection or vaccination rather just assuming all is well.
Personal case study
As one small part of a larger study of antibody semi-quantification post vaccination using AbC-19TM, we recently monitored the antibody response of my wife and me and compared the strength of responses with an antibody test line colour intensity score card which is now being made available by Abingdon Health.
The following case study illustrates the way in which antibody levels can influence an individual’s actions:
The graph illustrates a time-course of our antibody response after being given the AstraZeneca vaccine, with my wife going on to catch COVID-19 from our son, and me avoiding infection although all living together in the same house.
Although a case study of only two individuals, several points are worthy of note:
- Antibody response to vaccination differs between individuals and can be low after one vaccination. This example is of two people, Abingdon Health will shortly publish a study of multiple individuals studied in this way, some who had previously been infection and some who had not.
- Antibody levels rise more after the second vaccination and decline after vaccination
- It is possible to catch COVID-19 (PCR positive) after two vaccinations
- Antibody response is significantly greater (very high line intensity on the LFD) after infection post vaccination.
- The antibody response post this infection remains high at 8 weeks now post symptoms.
- One of the two people studied here (me) appears to require a booster vaccination whereas the other still has very high antibody levels and would not be in such need of a booster.
- The AbC-19TM LFD can be used to stratify those in need of vaccination (booster of otherwise).
This study is an example of what has occurred in one household in England. This is likely to be replicated in thousands of households throughout the UK? What is happening globally?
What we do know is that people respond differently to vaccine and therefore risks are different for different individuals. We also know people can catch COVID-19 following vaccination.
There is no one size fits all approach to combating the effects of COVID-19. On-site antibody testing provides a valuable tool alongside vaccines and antigen tests to combat the SARS-CoV-2 virus. Determining antibody status enables individuals to adapt their behaviour and help limit risks based on evidence.
As noted above we will release a study of multiple individuals studied in this way to further highlight the importance of antibody testing for individuals.
Author: Dr Chris Hand, Chairman of Abingdon Health
- Longitudinal observation and decline of neutralizing antibody responses, Seow J et al., Nature Microbiology vol 5 pp 1598-1607, 5 December 2020
- Dynamics of neutralising antibody titres in the months after SARS-CoV-2, Crawford K et al, Journal of Infectious Diseases, 30 September 2020
- Heterogeneous antibodies against SARS-CoV-2 spike RBD and nucleocapsid, Andrews K et al., JCI Insight vol 5, 17 September 2020