Covid-19: What we fail to understand about reinfection!

Researchers have discovered the principal strong proof that individuals can be reinfected with the infection that causes COVID-19. Recent reports shows a 33-year old person who was treated at the medical clinic for a mild case in March got reinfected when he was examined at the Hong Kong air terminal while returning back from Europe on 15 August, under 5 months. He had no symptoms this time.

In the US, there were many anecdotal reports of reinfections, but this time scientists have backed it with evidence. Analysts had sequenced the virus, SARS-CoV-2 (that causes covid-19), from the first disease; they did so again after the patient’s subsequent finding and found various contrasts between the two.

Kelvin, a clinical microbiologist at the University of Hong Kong (HKU) and one of the researchers of a paper working on it, revealed to Science today, “This case demonstrates that probably a few patients don’t have long lasting invulnerability,”

Medical scientists from the University of Hong Kong cited a paper in the journal Clinical Infectious Diseases where a few pages of the report are spreading on Twitter.

A first case of #COVID19 reinfection from HKU had shown distinct virus genome sequences in 1st and 2nd infection (142 days apart)

This is no cause for alarm – this is a textbook example of how immunity should work. Second infection was evidently asymptomatic. While immunity was not enough to block reinfection, it gave the person protection from disease, proclaimed a researcher.

Mark Slifka, a viral immunologist at Oregon Health & Science University , says his opinion from the paper is in contrast of what the authors write: “Even though the patient got infected with a very different strain that’s distinct from the first time around, they were protected from disease,” he says. “That is good news.”

Previous research has shown that neutralizing antibodies — immune system proteins that latch onto pathogens and inhibit them from infecting cells — can diminish in the months after a Covid-19 infection when the initial infection was mild. It has been distorted saying its the end of herd immunity hopes.

However, what we fail to to understand is that antibodies are only one component of the immune system, and losing them does not put person’s life at risk to virus. Indeed, there are numerous parts of the immune system that may provide lasting protection against SARS-CoV-2.

Alessandro Sette, an immunologist at the La Jolla Institute for Immunology, stated one among them is T-killer cells, which filter and destroy infected cells.”

Antibodies, can evacuate virus from bodily fluids. But if the virus gets inside the cell, then it becomes invisible to the antibody, which is where killer T-cells take charge. They find and destroy these hidden viruses, the immunologist added.

In the 1980s experiments, individuals who produced weaker immune responses during the first infection were most likely to be reinfected. Researchers assume that, it might have happened in the Hong Kong case.

Whether reinfected people can still spread the virus may turn out to be the crucial question, Houldcroft says, they don’t shed and are asymptomatic, it’s fine. If they are still infectious, that could cause problems.

The Health Minister of Telangana declared the day after the Hong Kong case was surfaced on the internet, that at least two cases of covid-19 reinfection have occured in the state.

Results of Hong Kong man’s two samples show that two sequences did not match – there was a total of 24 contrasting changes in the sequences of the SARS-CoV-2 virus from both infections.

What’s more, no antibodies appeared in a blood sample taken from him soon after his positive test at the airport during travel. This is an indicator that the second virus had not been lingering unnoticed for months, and clear evidence of reinfection.

The Indian Council of Medical Research (ICMR) Director-General Balram Bhargava said at a press meet that the Hong Kong case is a rare phenomenon and reinfection depends on multiple different factors.

“It can depend on several factors, one can be related to the patient itself, how is his immunity, how was his immune status, was it compromised. It can also depend upon the virus, whether the virus has mutated or turned virulent,” he stated.

Even though speculated as rare, the Hong Kong scientists emphasise the neccesity to be cautious and vigilant of the reinfection risk. These cases make analysts to be able to discern whether it’s a reinfection or just a relapse of first infection making them read closer to achieve a better understanding to eradicate corona virus.

Experts across the world are emphasising that reinfection is somewhat rare. Nonetheless, considering many oblivious factors about the SARS-CoV-2 virus, it might still be risky to propagate this theory as a well known fact. By postulating reinfection is not possible, might give people a false sense of belief, which could be threatening.

To simplify, the reinfection is not rare and anyone with weak immune response can be vulnerable. However, it’s not so alarming because the T-killer cells can identify and kill the virus and reduce the potentiality of the disease in the second infection. And sometimes due to the presence of varied strains people may catch infection, but it would be asymptomatic and less threatening.