There have been quite a few reports lately about people testing Covid-19 positive even after vaccination. A Gujarat health official tested positive for the virus even after the second dose of the vaccine. Punjab reported eight such cases where one tested positive after the first dose of the vaccine. Similar incidents were recorded in Pune, where two doctors tested positive even after the second dose.
Can you test positive after the Covid vaccine?
As per the World Health Organization (WHO) website, the vaccine would not cause a positive test result for PCR or antigen test. “This is because the tests check for active disease and not whether an individual is immune or not,” it states.
In the case of an antibody test, however, it may be possible to test positive. The serology test measures a person’s Covid-19 immunity. Since the vaccine prompts an immune response, so some antibody tests might show the result as positive, mentions the international public health agency.
Medical experts have termed such instances “breakthrough cases” whereby a fully vaccinated person gets the disease they are vaccinated for.
Centers for Disease Control and Prevention (CDC), which is currently researching the effectiveness of the Covid-19 vaccine, says there are multiple factors that affect how a vaccine works “in real-world conditions”. These include:
- Host factors such as people not included in clinical trials who may respond differently to the vaccine
- Programmatic factors such as following dosing schedules or storing and handling vaccines properly
- Virus factors such as variants
In the case of coronavirus, the window period is about two weeks after getting the second dose of the vaccine.