Covid-19 Reinfection: A Rapid Systematic Review of Case Reports and Case Series

Abstract

The COVID-19 pandemic has infected millions of people worldwide and many countries have been suffering from a large number of deaths. Acknowledging the ability of SARS-CoV-2 to mutate into distinct strains as an RNA virus and investigating its potential to cause reinfection is important for future health policy guidelines. It was thought that individuals who recovered from COVID-19 generate a robust immune response and develop protective immunity; however, since the first case of documented reinfection of COVID-19 in August 2020, there have been a number of cases with reinfection. Many cases are lacking genomic data of the two infections, and it remains unclear whether they were caused by different strains. In the present study, we undertook a rapid systematic review to identify cases infected with different genetic strains of SARS-CoV-2 confirmed by PCR and viral genome sequencing. A total of 17 cases of genetically confirmed COVID-19 reinfection were found. One immunocompromised patient had mild symptoms with the first infection but developed severe symptoms resulting in death with the second infection. Overall, 68.8% (11/16) had similar severity; 18.8% (3/16) had worse symptoms; and 12.5% (2/16) had milder symptoms with the second episode. Our case series shows that reinfection with different strains is possible, and some cases may experience more severe infections with the second episode. The findings also suggest that COVID-19 may continue to circulate even after achieving herd immunity through natural infection or vaccination, suggesting the need for longer-term transmission mitigation efforts.

Previous COVID-19 Infection and Antibody Levels After Vaccination

“…On the other hand, previously infected individuals have been shown to have some humoral protection against COVID-19 ( 19 ), although still prone to reinfection ( 20 , 21 ). Calls for global vaccine equity continue to fail as many developing countries are incapable of obtaining enough vaccines to protect a substantial proportion of the population.…”

The SARS-CoV-2 pandemic: remaining uncertainties in our understanding of the epidemiology and transmission dynamics of the virus, and challenges to be overcome

“…Reinfection has been hypothesized as occurring because of a short-lived high titre antibody response after the first infection but given the paucity of well-documented cases [ 92 ], little is understood about rates of reinfection at present, although more data are emerging both for vaccinated and unvaccinated individuals [ 77 ]. The pandemic is still in its early stages, so over the coming year, reinfection rates are likely to rise and will, therefore, yield more precise information on the duration of immunity both from infection and vaccination [ 93 ].…”

Sequencing SARS-CoV-2 from Antigen Tests

“…Although exceedingly rare, reinfection has been documented and is a threat to vulnerable populations. Although most suspected cases of reinfection were a resurgence of the same viral strain that initially infected the patient, other cases demonstrate reinfection with genetically distinct genomes [7,13]. Genome surveillance enables us to monitor for cases of reinfection and discern whether these cases are associated with particular variants.…”