A Spanish nurse is the first known case of Covid re-infection in less than 3 weeks

A 31-year-old Spanish nurse, who contracted Covid-19 twice in less than three weeks, has become identified as the quickest case of re-infection with the shortest known time gap between infections, in the world, according to a report to be presented at the European Clinical Microbiology and Infectious Diseases seminar that starts in Lisbon tomorrow (Saturday).

As we all know, overcoming Covid and being vaccinated is not a guarantee against infection, and according to this report, it may occur sooner than expected, as in this case it was only 20 days this Spanish woman went from contracting the Delta variant to being infected by Omicron.

She first tested positive on December 20^th 2021, in a routine PCR test during staff screening at her workplace. She was fully vaccinated and had received her booster dose 12 days earlier. She didn’t develop any symptoms and was isolated for ten days before returning to work.

On January 10^th this year, just 20 days after the first positive test, she developed a cough, fever and felt generally unwell, so had another PCR test which was also positive. Genome sequencing showed that the patient had been infected by two different strains of SARS-CoV-2. Her first infection was with the Delta variant, and the second was with the Omicron variant.

The Omicron variant had only been identified as a variant of concern by the World Health Organization (WHO) a month earlier and has become the dominant variant worldwide, being much more infectious than Delta with the ability to evade immunity from past infections and vaccinations.

“This case highlights the potential of the Omicron variant to evade prior immunity acquired either by natural infection with other variants or by vaccines. In other words, people who have had Covid-19 cannot assume that they are protected against re-infection, even if they have been fully vaccinated," says Dr. Gemma Recio, from the Institut Català de Salut, in Tarragona, one of the authors of the study.

“However, both prior infection from other variants and especially vaccination do protect against severe illness and hospitalization in people with Omicron.”

“This situation, the shortest case of coronavirus re-infection, also underlines the need for genomic sequencing of viruses in infections in those who are fully vaccinated and in re-infections, to help detect variants with the ability to partially evade the immune system,” she concludes.