Recovery from COVID19 does NOT Guarantee immunity?

What we currently know about Virus Reactivation & Reinfection

Design credits ~ Ms. Satya | Artist & Illustrator | Check out her Portfolio ~ https://instagram.com/divinesplendour

Through this entire blog post, I am going try to keep things as simple as possible, and wherever possible I shall explain in the manner that works best for my patients – through Analogies

Despite the gradual increase in the proportion of positive symptomatic cases seen by me and my colleagues, we have been fortunate enough to help most of them recover with home care and see them through to the other side. And once they recover, they are obviously extremely elated for a few days and then say see some news published by some random online figure or from the ever so elitist Whats app university and they get anxious again.

Most of the questions revolve around these 2  topics – Re-Infection & Reactivation

Let’s Start with Re-Infection …

What is it really? Since we are dealing with a whole new entity right now (COVID19), let’s take up a virus which has helped you apply for the maximum days of medical leave (it’s a fact as well) – Chicken Pox. I am sure you have seen or at least heard of cases wherein people get infected again. The chicken pox virus never really leaves your body when you get better, all it does is go for a long slumber at a cosy part in your spinal cord – The Dorsal root ganglion. Then years later you may suffer from something called as SHINGLES. It is nothing but the REACTIVATION of the chickenpox virus when your immunity gets tired and lets down its guard. Such a weakening could be because of a disease like diabetes, it could be because of treatment like steroids, factors like stress but for most its old age. Now coming back full circle, there has NOT yet been any study, publication or case suggesting that such a phenomenon is at play with regards to COVID19. This has more to do with the fact that COVID19 does not have a preferred adobe (cell type) that it likes to stay in, but it definitely has a preferred path of entry (ACE-2 Receptor). Another fact providing much needed relief is that other members of its family like MERS, SARS do not show such as capacity to stay dormant.  So the answer that any expert would give you right now is an outright NO. So relax.

Now let’s come to the most anxious question – IS REINFECTION POSSIBLE ? – The well-founded Theoretical answer is NO, but sadly we have seen otherwise as well.

Before we jump into the facts, let’s first understand what prevents reinfection. Once a new enemy (pathogen) enters our body, we produce what is known as the first defense to the pathogen which is called the primary immune response. The objective of this response is to halt the spread, analyze the enemy, and train the body’s troops for the next wave. This is primarily done by an Antibody called IgM (let’s call them Majors). So once the virus is broken down, it is processed in the organs like lymph nodes which act as training grounds for the next line of defense, the IgGs (let’s call them generals). So these generals have a lot more stamina, a lot longer lifespan and most importantly they have MEMORY of the enemy. So the next time the virus enters, the Major doesn’t even have to intervene, the generals already know what to do, leading to faster recovery. These guys are the ones that prevent reinfection till they are alive.

A study was done on SARS COV 1 (published on NCBI)  showed that such reinfection is not possible. In line with this a controlled study done on rhesus monkeys who were injected with SARS CoV2 also did not show symptoms of reinfection when they were challenged with the virus again after recovery. But there have been reports suggesting the opposite as well – A study that came out in Jama network showed  that a couple of patients have been readmitted after properly recovering and getting discharged from the hospital. The most shocking news came from South Korea where a record 111 people (who had successfully recovered) had gotten reinfected. But an overarching similarity (with most of them, not all), is that the so-called “second infection” was not as severe as the first one.

We have had a similar experience in India as well, there are a few reports of patients getting readmitted especially in the high risk metros. On paper such a phenomenon still defies all logic, so let’s then see why we are seeing such incidents.

Design credits & Special Thanks to Mr. Vishal Shishodia for creating this illustration to spread the message ~  https://www.linkedin.com/in/vishal-shishodia-394460149.

Reason 1 – Multiple strains

As of now, more than a dozen “major strains”  have been completely analysed and the data has been made public for those working on vaccines and treatment. It’s a number that will continue to grow in the time to come.

Reason 2 – Higher Infectivity of new strains

The mutation — named the “D614G”  mutation— occurred on the spike protein, the part of the virus that helps it bind and fuse to our cells. The D614G mutation makes it easier for the virus to infect our cells. Of the 82 strains of the virus circulating in India nearly 50% were found to be having this new mutation. This analysis was done by India-born Prof S.S. Vasan and his colleagues from the Commonwealth Scientific and Industrial Research Organisation (CSIRO) in Australia

Reason 3 – Poor Testing sample

This is one reason I suggest my patients stay away from the so called “easy to use” home tests which use a drop of your blood. One has to understand that the specimen used for testing and the type of test has a huge role to play in determining the presence/absence of infection.. The order of preference for sample is as follows

1. Broncho alveolar lavage – they insert a tube down your throat and suck a small sample of the fluids inside (not as gross as it sounds)

2. Nasopharynx – from the back of your nose, collected with the long swab (again not as painful as it appears to be)

3. Oropharynx – Collected from the backside of your throat

4. Sputum – Good old coughed out phlegm

Reason 4 – Change in protocol

When discharging the patient, we used to take a test to check whether they have turned negative, however this practice has been discontinued. If the patient is asymptomatic for 10-14 days post the first positive test, they are usually sent home with the badge of recovery. So in essence we still don’t know if they are positive or negative.

Reason 5 – False Negativity

When a study was conducted to compare CT and RT-PCR, the latter fell way behind. Results of the study indicated 59% (n = 601) of the patients had positive RT-PCR results and 88% (n = 888) had positive chest CT scans. In patients with negative RT-PCR results, 75% (n = 308) had positive chest CT findings (that’s a whopping number).

Reason 6 – Supportive > Definitive Therapy

COVID19 predominantly causes a self-limiting infection, so let’s give credit only where it is due. Our treatment approach is purely supportive as we do not have definitive treatment yet. It’s like a mystery book unravelling a new secret with every page we turn. First we observed that HCQ is effective only in mildly symptomatic cases, then we learnt that the biphasic fever is due to the body’s immune system going haywire. This has led some to look at steroids as routine medications. Therefore, we can never be sure whether the treatment actually eliminated / eradicated the virus from the body or was it the work of the immune system.

Reason 7 – Residual viral particles

This seems to be the most likely explanation. Just because you are tested positive in RT-PCR, doesn’t mean the virus is “alive”. Remember we only test for particles of the virus, so the test will still show positive if the sample has completely disintegrated portions of the virus. It’s akin to having the taste of your favorite beverage lingering in your mouth (and your head) for a long time after indulging in it – Albeit this is not the same “Corona” you wish you had binged.

Sadly after reading all this I am sure you have understood that this virus has become an inevitable part of our lives, or for a few, even a part their genomes (possible,but yet to be confirmed). Whether you like it or not, it is here to stay, just like all the other viruses before it and surely this will not be the last.

Let’s make sure the lessons learned and the sacrifices made get embedded in our culture and in our way of life, that way another century down the line, our descendants don’t make the same mistake we & our ancestors made. 

The article was originally written by me for the publication “The Science Serve”. It has been republished here with permission.