The thought of contracting COVID-19 infection is unsavory in itself. Now, Health care units are noting increasing number of cases of suspected reinfections. All such cases have one unique episodic feature, second episode of infection being more severe than the first one.

The key features of severity of COVID-19 reinfection are oxygen dependency, new symptomatology with radiological worsening, breathlessness, cough, fever, body myalgia etc. There is an immediate need of genome sequencing to confirm such reinfection cases.

Although, reinfection within six months of first episode of COVID-19 infection is rare due to protective immunity. But in recent times, a mysterious spate of COVID-19 reinfections has been reported [1]. The mystery revolves around many pillars like inadequate immune response (the first time), waning immunity, or mutant strain infection. So, these contribute to the key factors responsible for the etiology of possible COVID-19 reinfections worldwide.

Firstly, there is a possibility of inadequate immune response during the first episode of COVID-19 infection [2], resulting in bounce back of reinfection with severe symptoms like breathlessness, cough, fever, lung involvement often seen on CT scans.

Secondly, there is a chance of waning immunity, which imparts the progression to the COVID-19 reinfection [3].

Thirdly, there is also possibility of mutant strain infection. In the Sars-CoV-2 virus or COVID-19, reinfections happen when a mutated version of the same virus successfully evades the immune system. According to the recent study by Professor Vinod Scaria, a pioneer in Precision Medicine and Clinical, Genomics at the Institute of Genomics and Integrative Biology (IGIB) New Delhi, some 80 such genetic mutations have already been found in research lab settings worldwide. 

In addition to this, there are other major factors like lack of genomic confirmation, underreporting, financial constraints owing to the expensive genomic sampling, CT scans, COVID suspected ICU Settings etc.

All in all, there is an immediate need to look for the long-term effects of COVID-19 to decode the mystery of Spate of COVID-19 reinfections.

1. To, K.K.W., et al. “COVID-19 re-infection by a phylogenetically distinct SARS-coronavirus-2 strain confirmed by whole genome sequencing.” Clinical Infectious Diseases, August 2020, https://doi.org/10.1093/cid/ciaa1275.

2. Long, Q.X., et al. “Clinical and immunological assessment of asymptomatic SARS-CoV-2 infections.” Nature Medicine, vol. 26, no. 8, 2020, pp. 1200–1204.

3. Malfertheiner, S.F., et al. “Immune response to SARS-CoV-2 in health care workers following a COVID-19 outbreak: a prospective longitudinal study.” Journal of Clinical Virology, vol. 130, 2020, article 104575.