Covid-19: Is it possible to have the infection without knowing and should you be bothered?

The ubiquitous presence of highly infectious coronavirus around us, life going back to normal with the lifting of restrictions, and precedence of asymptomatic cases often make one wonder what if they get Covid-19 infection without knowing. Even several studies have shown that the diagnosed Covid-19 cases are just the tip of the ice-berg of many undiagnosed cases. Here’s everything about having Covid without not knowing and if you should be concerned.

How Covid is diagnosed and how to know if there was an infection before without symptoms

Most people who go for Covid testing like RT-PCR are symptomatic or have someone in a close circle with symptoms that ranges from fever to congestion in the upper respiratory tract. A swab test is done for results. In 2022 with a massive spread of infection, mild in most cases, many did not take a PCR or RAT test but presumed themselves positive and quarantined.

But past infections can be identified if on going through a blood test, the Nucleocapsid (n) proteins are detected. They are the antibodies launched by the body’s natural immune response for preventing the virus to attach to human cells. They are formed within 1-3 weeks and last for six months. Detection of antibodies to the S protein, however, only indicates vaccination (but not infection).

Limitations with Covid-antibody tests

There is still much to learn about the body’s immune response against Covid-19. Not everyone can develop a detectable amount of antibodies and their levels decline over months in some people. Moreover. Other circulating viruses like the common cold can also trigger the body to make N proteins leading to ‘false positives

But antibody testing should be done in special cases like knowing the effectiveness of the vaccine, for serosurvey, diagnosing post-infection complications or of the person is eligible for a certain treatment etc. It can be also used for assessing the background population rate of infection.

Antibody testing on a population

Antibody testing is majorly done for seroprevalence studies to find if a certain population has attained collective or herd immunity. Blood from blood banks is used that represents the general population. A yet-to-be peer-reviewed study by the World Health Organization reported the results of a meta-analysis of over 800 seroprevalence studies performed around the world since 2020.

According to the report by July 2021, 45.2% of the global population had SARS-CoV-2 antibodies, eight times the estimate from a year earlier. Fresh serosurvey will understand the extent to which the Omicron wave creates antibodies in the general population.

How having covid infection without knowing can matter in future

Some studies say that people with mild or asymptomatic infection have less effective antibody response compared to those with severe illness, but that cannot be linked to its response to re-infection. Also, knowledge about having antibodies from past infections should not deter one to take Covid vaccination, which still remains the best protective care.

The likelihood of people developing persistent or relapsing symptoms like shortness of breath, muscle fatigue, exercise intolerance is higher in those who suffer a heavier initial bout of Covid illness with a higher viral load.

Takeaway

As we enter the third year of the Covid-19 pandemic and considering one in three infections may be asymptomatic, it is likely many of us who were not diagnosed with PCR report have been infected without knowing it.

But unless you are experiencing conditions like lingering fatigue, brain fog, you can be least bothered and know that your COVID infection status is unlikely to be of much practical benefit. For such cases, antibody testing should be taken only for specific medical or public health indications.