16/11/2022
Risks of Covid-19 reinfections
Dr Veena Aggarwal, Consultant Womens’ Health, CMD and Editor-in-Chief, IJCP Group & Medtalks Trustee, Dr KK’s Heart Care Foundation of India 16 November 2022
Repeated Covid-19 infections increase the risk of hospitalizations as well as mortality irrespective of being vaccinated, according to a new study published online in the journal Nature Medicine.1 Additionally, the risk of long Covid is also elevated.
Researchers analysed medical records of about 5.8 million veterans from a US Department of Veterans Affairs healthcare database from March 1, 2020, through April 6, 2022 accounting for the time when the ancestral, delta, omicron variants were in circulation. This included a group of 443,588 people with one infection of SARS-CoV-2 and 40,947 people with reinfections, who had had at least two or more confirmed infections. Few patients had four infections. None of them had ≥5 infections. Around 5.3 million people who did not have Covid-19 acted as controls. The aim of the study was to investigate the risks of frequent infections within 30 days and up to 6 months.
Analysis of data revealed that the risk of hospitalization increased 3-folds among people who experienced reinfection compared to those who did not have reinfection with a hazard ratio of 3.32. The risk of having at least one sequela of infection was increased 2-folds with HR of 2.10. The all-cause mortality risk also doubled with HR of 2.17.
Compared to those with no reinfection, the sequelae in patients with reinfection were pulmonary disorders (HR 3.54), cardiovascular disorders (HR 3.02), coagulation and hematological disorders (HR 3.10), fatigue (HR 2.33), gastrointestinal disorders (HR 2.48), kidney disorders (HR 3.55), mental health disorders (HR 2.14), diabetes (HR 1.70), musculoskeletal disorders (HR 1.64) and neurological disorders (HR 1.60). The risk increased with each new episode of infection.
This study has demonstrated that risks of adverse outcomes associated with reinfections, which included hospitalizations, multiple sequelae and even death in the acute phase as well as at six months in the post-acute or the long Covid phase. It also highlights the need to be vigilant about Covid-19. The pandemic is receding, but is not over yet. New and more infectious variants are emerging and causing spurts in cases in various parts of the world. With winter just around the corner, it’s not time yet to let down our guard. Masking, hand hygiene, vaccination including boosters are as important now as before to prevent infection and reinfection.
Reference
Bowe B, et al. Acute and postacute sequelae associated with SARS-CoV-2 reinfection. Nat Med. 2022 Nov 10. doi: 10.1038/s41591-022-02051-3.
