Covid-19 Live Updates: Researchers Document The First Case Of Virus Re-infection

Shamie Dasgupta

20th October, 2020

Who would have thought that there would be a time when the entire world would come to an indefinite standstill?

No traffic on the roads, no buses carrying children to school, no metro trains stopping at the stations, and no busy pedestrians walking along the street to return home after work. This pandemic somehow made our daily monotonous schedule seem like a far-fetched dream. Those who had been desperately wishing to get more holidays from work now seem eager to get back to their jobs.

And just when we all thought that this virus has revealed all its true colours, COVID-19 struck yet another blow to the countless research and clinical discoveries.


The first COVID -19 re-infection case to be documented:


Researchers in Hong Kong have reported the first COVID-19 re-infection. A thirty-three-year-old man who had been infected by SARS-COVID-19, again contracted the virus while traveling in Europe about four months later. After sequencing the virus from the patient’s infections, it was discovered that they did not match. There was a difference of 24 nucleotides between the two strains causing separate infections. It was also noted that the man’s second case was milder than the first, indicating that his immune system was providing some level of protection against the virus.


What is re-infection?


Re-infection or recurrent infection is defined, as infection occurring in people who have already gained limited immunity from their previous experience with the same virus. A ‘second attack’ depends on how much and for how long a person has gained immunity from the previous bout of infection.

Our immune system is split into two parts: the innate immune response and the adaptive immune response. In the case of coronavirus, only the ‘adaptive immune response’ helps in providing immunity to our body. The adaptive immune response includes T-lymphocytes that produce targeted antibodies that can stick to the virus and fight against their actions. 

Generating antibodies that specifically target the coronavirus takes time – about ten days.

If the strength of the adaptive immune response is strong enough, it could protect against the infection for a brief amount of time.

Now the predicament with the COVID-19 virus is that it has not been around long enough to observe the longevity of the immunity. We may get an intuitive idea from studying the other human coronaviruses, but the actual duration is yet to be ascertained.


Is one case of re-infection enough to reach a verdict?


Just one case is not enough to speculate on any outcomes. More data is required for further analysis. There have been a few dispersed cases of re-infection floating across the world, but those reports have been deemed inaccurate due to faulty testing and unreliable evidence. Some experts say that this case could be an outlier amongst the millions of cases reported worldwide. To reach a more definitive conclusion researchers are going to keep track of ongoing COVID-19 patients and those who have already recovered from the infection.

Another question unanswered is the longevity of immunity. Experts say that a major step in fighting against COVID is to learn about the longevity and the strength of the immunity. If more cases of re-infection arise then it may open more paths for the ongoing research.



1. First Covid-19 reinfection documented in Hong Kong, researchers say. (2020, August 24). STAT.


2. Coronavirus immunity: Can you catch it twice? - BBC News. (n.d.). Retrieved October 9, 2020, from


3. Scientists target coronavirus immunity puzzle—BBC News. (n.d.). Retrieved October 9, 2020, from 


4. Recovery from coronavirus may not confer immunity, warn experts. (2020, April 17). Deccan Herald.

About the Author


Currently majoring in Statistics and an art aficionado.