Some governments/authorities have suggested that the detection of antibodies to the SARS-CoV-2, the virus that causes COVID-19, could serve as the basis for an “immunity passport” or “risk-free certificate” that would enable individuals to travel or to return to work assuming that they are protected against re-infection. There is currently no evidence that people who have recovered from COVID-19 and have antibodies are protected from a second infection.
SARS-CoV-2 antibodies in patients who had had COVID-19: Implications
The duration of antibody after getting COVID-19 is short-lived or may not develop at all.
In a Chinese study, very few people having had COVID-19 had the antibodies detected few months later (1). In a report from United kingdom, most of the patients had the antibodies up to 8 weeks, although some of the patients never develop the antibodies (2).
Implications of these results include:
1. The duration of antibodies after COVID-19 is short lived.
2. Antibodies may not indicate protection from reinfection
3. Vaccine development may halt, because the immunity may be only few weeks and may not be worth the cost.
4. The possibility of immune passport is dead.
1. https://www.medrxiv.org/content/10.1101/2020.06.13.20130252v1.full.pdf
2. Preprint Evaluation of antibody testing for SARS-Cov-2 using ELISA an...
Paces J, Strizova Z, Smrz D, Cerny J. COVID-19 and the immune system [published online ahead of print, 2020 May 29]. Physiol Res. 2020;
People who survive a COVID-19 infection continue to produce protective antibodies against the virus for at least 3-4 months after developing their first symptoms.
https://directorsblog.nih.gov/2020/10/20/two-studies-show-covid-19-antibodies-persist-for-months/
Please also see the following RG links.
Article Longitudinal observation and decline of neutralizing antibod...
Article Seasonal coronavirus protective immunity is short-lasting
Article Rapid Decay of Anti–SARS-CoV-2 Antibodies in Persons with Mi...