Unvaccinated people who account for half of patients with severe COVID-19 in intensive care have a very different medical profile than patients who have adhered to the vaccination schedule.
As we previously stated in a January 19 article, all properly immunized people who require intensive care suffer from a significant impairment of their immune system due to organ transplants, chemotherapy, hemodialysis, autoimmune disease, primary innate immunodeficiency, poorly controlled HIV infection, or even old age.
As for people who are not vaccinated, or who have only received a single dose of vaccine and who end up in an intensive care unit because their COVID-19 has seriously worsened, they present in the vast majority cases an underlying risk factor. Most often, they have a chronic disease, such as hypertension, diabetes, lung disease or cardiovascular disease. Obesity is also an important risk factor because, when none of these medical conditions are present, being overweight frequently emerges as the factor that played a crucial role in the development of a severe form of COVID-19. .
A study published in theInternational Journal of Obesity and carried out at the CHUM showed that each increase of 10 points in the body mass index (for example a body mass index of 35 kg/m2, compared to 25 kg/m2, which corresponds to ideal weight) tripled (3.5 times) the risk of dying from COVID-19 in intensive care, even after taking into account the possible effect of age, sex, diabetes and high blood pressure.
“All of these factors were described at the start of the pandemic as increasing the risk of developing a severe form of COVID-19 likely to require intensive care. They are of the same order as before the vaccination, whereas for the vaccinated, the risk factors have changed and are all associated with a deficiency in the immune system, which prevents it from responding well to the vaccine. They are therefore very different from those of the non-vaccinated”, notes the DD Madeleine Durand, specialist in internal medicine at the CHUM.
People who are obese, hypertensive, diabetic, heart and lung disease are no longer among those vaccinated who end up in intensive care with severe COVID-19. This demonstrates that “all of these people can benefit from the protection provided by the vaccine, because these comorbidities do not affect the ability of the immune system to develop immunity following vaccination. They do not prevent you from responding well to the vaccine, ”explains the DD Durand.
Although much more rarely, hospital intensivists also encounter young, thin, perfectly healthy people who are struck down by a severe form of COVID-19. “Indeed, it sometimes happens that no other medical reason can be found than the sole status of not being vaccinated to explain the serious COVID that a young person presents. During the first wave, the media reported cases of young and healthy people, including a triathlon athlete, who died of COVID. It’s a bit of the tragedy of this disease, we are not yet able to predict precisely which individual will have a serious COVID and die from it. There’s still this filthy lottery in COVID-19 that remains where you can’t 100% predict, based on health, age and gender characteristics, whether someone will have severe COVID-19. “, underlines the DD Durand.
“A huge risk”
The factor that most increases the risk of developing a severe form of COVID-19 and ending up in intensive care in people who are not adequately vaccinated is their unvaccinated status. According to data from the Santé Québec site, this relative risk is 12 times higher than that of people who have received two doses of vaccine, or even three doses.
“A person who smokes has a 10 times greater risk of developing lung cancer and a 2.5 times greater risk of developing heart disease than someone who does not smoke. In medicine, a risk twice as high is considered a huge risk, ”raises the DD Durand to illustrate the extent of the risk of not being vaccinated.
The population of patients suffering from a severe form of COVID-19 and who end up in intensive care is quite young, at least younger than that who lives on the floors of the hospital, and this, as much among the vaccinated as among the the unvaccinated. This is so because the elderly who are very fragile are only very rarely taken there, because they could not survive the aggressive treatments used in these care units. These elderly patients who are most often vaccinated therefore remain upstairs, and if their COVID-19 worsens, they are offered palliative care instead. “It would be futile and even cruel to subject people with geriatric frailty syndrome to two, three or even four week intubations and cardiopulmonary bypass. It would not be medically reasonable to send to intensive care elderly people with cognitive impairment, who cannot move from their bed to a chair and for whom there would be no prognosis for long-term recovery. , explains the DD Durand.
There is therefore no marked age difference between vaccinated and non-vaccinated patients present in intensive care units. “Even the vaccinated are relatively young, because people with a deficiency in their immune system due to a transplant or a primary disease of the immune system, for example – who make up the vaccinated group – are young. We will not transplant a lung or bone marrow to an elderly person”, specifies the specialist in internal medicine.
The latter also recalls that “even if the Omicron variant is generally less severe than the variants that preceded it, the severe form of COVID-19, as seen in the other waves, still exists. “Even if in proportion, the virus [ce variant] gives fewer serious cases, people who are unlucky to have a severe form of COVID-19, even at the time of the Omicron wave, are excessively sick, they are just as sick as in previous waves. These people do not make a completely different disease. Omicron induces a disease of which we must still be wary”, points out the DD Durand.
Another observation that underlines the effectiveness of the vaccine: while unvaccinated people represent only 10% of the adult population of Quebec, they account for 40 to 50% of patients with severe COVID-19 in care units. hospital intensives. If the vaccine had no effect, the severe form of the disease would appear as frequently in the vaccinated as in the non-vaccinated, and this would result in the presence of 90% of vaccinated and 10% of non-vaccinated people. in intensive care units.