The long COVID even with Omicron

You have an 8% chance of developing the condition if you’re vaccinated, according to new data

What is the probability of developing a long-lasting COVID of at least one month? 7% to 9% in adequately vaccinated people, according to UK government data published on Friday.

These early data on prolonged COVID with the Omicron variant confirm that: 1) the vaccine greatly reduces (by half, according to UK Public Health) the risk of developing prolonged COVID; 2) the less virulent Omicron variant is half as likely to cause prolonged COVID as previous variants.

Before the vaccine, around 40% of patients who contracted COVID-19 (parent strain of coronavirus, Alpha, Delta variants) developed long-standing COVID of at least three months, and 46% of patients developed long-term COVID. long duration of at least three months. least one month, according to a Quebec study conducted before the vaccination campaign^one.

But the vaccine greatly reduces the chances of having prolonged COVID. As of April 3, between 7% and 9% of UK adults who received the triple vaccine had COVID for one to two months, according to data released Friday by the UK Office for National Statistics.^two (the equivalent of Statistics Canada). The percentage (prevalence rate) varies between 7% and 9% depending on the variant responsible for the infection (Delta, Omicron BA.1, Omicron BA.2). About 9% of UK adults with two doses of the vaccine have prolonged COVID one month after infection with Omicron BA.1.

A third dose of the vaccine would roughly halve the odds of contracting prolonged COVID with Delta (risks reduced from 15.9% to 8%), but would have no significant effect against prolonged COVID with Omicron BA.1 , based on UK data. . (Omicron is the dominant variant in Quebec and many countries today.)

“Among triple-vaccinated adults, we estimate that approximately one in 15 people infected with the Omicron BA.1 variant will have long-lasting COVID symptoms one month after infection. This proportion would rise to one in 12 people infected with the Omicron BA.2 variant,” says Daniel Ayoubkhani, Senior Statistician at the Office for National Statistics.

Some facts about the long COVID

Long COVID is the disabling version of COVID, causing one or more symptoms (fatigue, shortness of breath, cognitive decline, headaches, muscle pain, loss of taste or smell, etc.) lasting at least one month (definition US) or at least three months (World Health Organization definition) after contracting COVID. Some patients with the most severe form of long-term COVID become totally disabled: they can no longer work or carry out their activities because they are tired or physically affected.

As of April 3, around 2% of Britons had had long-term COVID for at least three months. They are 1.3 million people. Around 1.8 million Britons had had long-term COVID for at least a month (2.8% of the population) and 0.8 million for at least a year (1.2% of the population).

If we apply this 2% rate to Quebec, approximately 138,000 Quebec adults would have experienced prolonged COVID of at least three months.

The Quebec Ministry of Health and Social Services does not disclose the number of patients with prolonged COVID.

A “very significant” effect, according to D.^D Thomas

Prolonged COVID should not be taken lightly, experts warn.

“We anticipate that it will probably have a very significant effect [substantial] said the d.^D Theresa Tam, director of public health for Canada. “We are still trying to understand the long COVID. » The advice of the D^D Thomas? “If he doesn’t get COVID, he won’t have COVID for very long,” she says.

“We must not trivialize the long COVID, even if it was worse at the beginning of the pandemic when people were not vaccinated,” explains the epidemiologist Gaston De Serres, chief physician of the immunization scientific group of the National Institute of Public Health of Quebec (INSPQ).

Not all long COVIDs are so bad. Some are unpleasant, like when you lose your sense of smell, but they allow you to live relatively normally. On the other hand, patients see their lives completely turned upside down. Going for a walk can take hours of recovery.

In the UK, 20% of patients with long-standing COVID (at least three months) feel they have greatly reduced their daily activities (severe form), compared to 47% of patients with slightly reduced activities. activities (mild form) and 33% of patients without impact on their quality of life (very mild form).

“We do not want to sow fear, it is not productive. But people need to be aware that the risks of developing complications with prolonged COVID are real, even if they are lowered by vaccination, new variants, and the impact of new drugs. These risks are not going to go away and the consequences can be serious,” says Dr.^D Emilia Falcone, director of the post-COVID research clinic at the Montreal Clinical Research Institute (IRCM) and specialist in infectious diseases at CHUM.

Symptoms and causes

The main symptom of prolonged COVID: fatigue, which affects 50% of patients with prolonged COVID for at least three months in the UK. Then come, among other things, shortness of breath (34% of patients), loss of smell (31%), difficulty concentrating (25%), muscle pain (24%), loss of taste (24%), pain headache (22%), memory loss/confusion (20%), sleep disturbance (19%), cough (17%), and anxiety (17%).

Can prolonged COVID develop during reinfection with Omicron? Yes, indicate the D^D Falcone, who has seen cases at his Montreal clinic.

Scientists are still looking for the cause of the long COVID. Five main hypotheses are proposed.

1. In some cases, particularly in patients hospitalized during the infection or with a severe infection, the inflammation during the infection leads to damage to the tissues around the blood vessels and to various organs, including the lungs.
2. Virus particles could remain in the body and cause sustained inflammation.
3. The viral infection would alter the immune system and attack the body (autoimmune disease).
4. The virus would enter the intestine and alter the intestinal flora, which would cause inflammation in the rest of the body.
5. The formation of microclots in the blood vessels would cause damage to various organs, including the nerves (which would explain certain neurological symptoms).

1. The Quebec study was conducted among 6,061 healthcare workers between July 2020 and May 2021 (approximately 95% of study participants were unvaccinated). A study conducted by the University of Oxford before the vaccination campaign reached the same conclusion.

2. UK Long COVID data by variant and vaccination status includes cases of first infections from mid-May 2021 to mid-April 2022.