Long COVID risk is slightly reduced after vaccination

According to a study of more than 13 million people, vaccination against SARS-CoV-2 reduces the risk of long-term COVID after infection by only about 15%1. This is the largest cohort ever used to find out how much the vaccine protects against this condition, but it is unlikely to end uncertainty.

Long COVIDs (diseases that last weeks or months after being infected with SARS-CoV-2) have proven difficult to study, especially because the sequence of symptoms makes them difficult to define. It was even difficult to know how common it was. Some studies suggest that it also occurs in 30% of people infected with the virus. However, a November survey of about 4.5 million people treated at US Department of Veterans Affairs (VA) hospitals found that the total number was 7%, less than those who were not hospitalized. Is shown.

Another mystery is whether long COVIDs are unlikely to occur after a breakthrough infection. One is the vaccinated person. In a May 25 Nature Medicine study, VA St. Louis Healthcare Systems nephrologist Ziyad Al-Aly and his colleague (the same team who wrote the November study) in St. Louis, Missouri, joined January 2021. I checked the VA health records from to December. Includes approximately 34,000 vaccinated persons with the breakthrough SARS-CoV-2 infection, 113,000 infected but unvaccinated, and more than 13 million uninfected.

Armor gap

Researchers have found that vaccination appears to reduce the chances of an infected person having a longer COVID by about 15%. This is in contrast to previous small studies that found much higher protection rates. This is also a deviation from another large study that analyzed self-reported data from 1.2 million UK smartphone users and found that two doses of the COVID-19 vaccine halved the risk of long-term COVID. I have.

The authors of the latest study also wrote about brain fog and malaise in vaccinated and unvaccinated individuals for up to 6 months after a positive SARS-CoV-2 test. I compared the symptoms. The team found no difference in the type or severity of symptoms between those who were vaccinated and those who were not. “It’s the same fingerprint you see in people with breakthrough infections,” says Al-Aly.

He states that there were more than 83 million COVID-19 infections in the United States alone. If even a small percentage of them turn into long COVIDs, “it’s a surprising number of people with a mysterious illness.”

The limited protection provided by the vaccine states that withdrawal measures such as mask obligations and restrictions on social distance can endanger more people, especially those with a weakened immune system. Means “We literally rely almost exclusively on vaccines to protect us and protect our people,” says Al-Aly. “Now we say we only protect you 15%. You remain vulnerable and very so.”

“Generally speaking, this is horrifying,” says David Putrino, a physiotherapist at Mount Sinai Health System in New York City, who has been studying COVID for a long time. He praises studies that were difficult to carry out due to the quantity and quality of the data, but adds that it is limited because it does not classify the data by important factors such as the medical history of the participants. “These are very important questions that we need answers to,” says Putrino. “There is no well-constructed research yet.”

Another unknown Omicron

Stephen Dikes, an HIV researcher at the University of California, San Francisco, points out that the study does not include data from people infected during the period when the Omicron mutant was causing the majority of the infection. .. “There is no data on whether Omicron causes long COVIDs,” he says. The findings “apply to dramatically changing pandemics,” he adds.

However, Dikes adds that the results indicate the need for further research on long-term COVID and the need to accelerate the development of treatments. “We have no definition, no biomarkers, no imaging tests, no mechanisms, or cures,” he says. “I have a question.”

This article has been duplicated with permission First edition May 25, 2022.