Spain reports more Covid re-infections in a fortnight than the rest of the pandemic | Coronavirus

The number of Covid re-infections reported in Spain over the past fifteen weeks has exceeded the total number of repeated infections documented during the rest of the pandemic, according to the latest data from Spanish researchers.

In the space of two weeks in late December and early January, 20,890 re-infections were reported in Spain, according to figures from the state-backed Carlos III Health Institute.

While the bulk of cases appeared to be mild, the number is more than the 17,140 cases of reinfection documented since the start of the pandemic until December 22. Spanish data includes both confirmed and suspected re-infections.

Researchers have attributed the growing number of repeated infections to the rapidly spreading Omicron variant. “Prior to this variant, re-infections were anecdotal globally,” immunologist Professor Alfredo Corell of the University of Valladolid told Spain’s Nius news site. “Omicron has changed this paradigm.”

The Spanish data adds to previous research that has linked Omicron to an increase in re-infections. A report published by researchers at Imperial College London in mid-December estimated the risk of re-infection with Omicron to be 5.4 times greater than with Delta.

“This study provides further evidence of the very important extent to which Omicron can evade prior immunity given both by infection or by vaccination,” said study director Professor Neil Ferguson in a press release at the time.

The report, modeled on those who tested positive in England in late November and early December, gave new impetus to a call from scientists to include re-infections in UK Covid numbers.

In South Africa, where the Omicron variant was first identified, preliminary research has suggested that the variant appears to be re-infecting people at a rate three times that of previous strains.

“The previous infection protected against Delta, but now, with Omicron, that doesn’t seem to be the case anymore,” Professor Anne von Gottberg of the South African National Institute of Communicable Diseases said in early December.

The findings of the United Kingdom and South Africa were taken online by the World Health Organization at the end of December. “People who have recovered from Covid-19 are three to five times more likely to be re-infected with Omicron compared to Delta,” he said in an update on Covid-19.

A study limited to the United States suggested that those reinfected with Omicron may have fewer and milder symptoms compared to infections caused by previous strains of the virus. The study, published by the US Centers for Disease Control and Prevention, looked at a cluster of Omicron cases in a family of six in Nebraska and found that the five re-infections were reportedly less severe than previous episodes of virus.

In Spain, researchers have highlighted several factors that may explain the increasing number of re-infections. “Either the virus mutates or a person’s immunity wanes,” said Dr Pere Domingo, Covid coordinator at Barcelona’s Santa Creu i Sant Pau hospital, in comments to El País. “In this wave, we have seen both factors at play.”

Others have suggested that the potential for reinfection is magnified given the large number of reported Covid-19 cases. “Even if the possibility of re-infection is low – say, one in 100 – if there are millions of infections, the re-infections number in the tens of thousands,” Professor José Antonio López Guerrero, of lópez Guerrero, told Nius. ‘Autonomous University of Madrid.

In recent weeks, the number of Covid cases in Spain has reached record levels, pushing the 14-day infection rate to 2,723 cases per 100,000, according to the latest figures from the Ministry of Health. To date, the sharp increase in cases has not translated into an increase in hospitalizations; the number of patients in intensive care units is about half that of a year earlier.

Spain’s Prime Minister Pedro Sánchez said last month he was convinced the country’s high vaccination rate – hovering around 80% of the population – would result in a softer wave as the country grapples with the Omicron variant. “We are obviously going to see a high number of infections, but no hospitalizations and intensive care admissions compared to previous waves,” he told reporters.

Edward K. Thompson