Fully vaccinated Spanish woman infected with Omicron

A 31-year-old woman in Spain contracted the Omicron infection just 20 days after the Delta variant, in what is claimed to be the shortest known gap between infections, according to the researchers.

However, in a similar case, a rare advanced infection was reported in a 61-year-old Delhi doctor vaccinated in 2021, who contracted the Alpha and Delta variants within 19 days.

The Spanish woman, who was a health worker, first tested positive for the infection on December 20, 2021, in a PCR test during the evaluation of staff at her workplace.

She was fully vaccinated and had received a booster shot 12 days earlier.

The patient, who did not develop any symptoms, was isolated for 10 days before returning to work.

On January 10, 2022, just 20 days after the first positive test, he developed a cough, fever and malaise and had undergone another PCR test which was also positive.

Whole-genome sequencing showed that the patient had been infected by two different strains of SARS-CoV-2: in December it was the Delta variant and the second in January was the Omicron variant.

“This case highlights the potential of the Omicron variant to evade earlier immunity acquired naturally with other variants or with vaccines,” said Gemma Recio, Institut Catala de Salut, Tarragona, Spain.

In other words, people who have had Covid-19 cannot assume they are protected from reinfection, even if they have been fully vaccinated, Recio added.

However, he said that together, prior infection and vaccination partially protect the patient against severe disease and hospitalization.

“This case also highlights the need for genomic surveillance of viruses in infections in fully vaccinated individuals and reinfections. This monitoring will help detect variants with the ability to partially evade the immune response,” Recio said.

The case report will be presented at this year’s European Congress on Clinical Microbiology and Infectious Diseases to be held in Lisbon, Portugal, from April 23-26.

A Delhi doctor, Veena Aggarwal, was infected with Covid-19 three times, contracting the Alpha and Delta variants after vaccination.

Aggarwal first tested positive on August 16, 2020, and was asymptomatic. He received his first dose of the Covishield vaccine on February 1, 2021, followed by the second dose on March 15, 2021.

On April 12, he tested positive for the second time and presented symptoms such as acute abdominal pain, fever, myalgia and fatigue. In 19 days, on May 3, he tested positive for the third time.

The infection resulted in hypoxia, hospitalization, and illness that lasted seven weeks. Whole-genome sequencing showed that the second infection was caused by the Alpha variant and the third by the Delta variant.

Their case, reported in the peer-reviewed medical journal Frontiers in Medicine, identified a rare advanced infection within 19 days and also confirmed it as reinfection, presenting the first documented case of two reinfections and two advanced infections.