Today’s Covid-19 can cause premature death years later

In the northern hemisphere we are approaching the winter months and suffering from colds and respiratory diseases will be common. In fact, the data in Oceania indicates that the flu wave may be especially aggressive in 2022-2023.

To this we must add that it will most likely come together with another wave of Covid-19 with the current, more efficient variants. That is why the WHO has already warned that measures be taken in Europe and primary care be reinforced. We are going to need it.

Beyond the usual respiratory symptoms (which can range from a cold to fatal pneumonia), it is worth paying attention to another worrying fact: SARS-CoV-2 and other respiratory viruses can trigger cardiovascular symptoms.

In fact, the knowledge we have of the aftermath of other pandemics indicates that these symptoms can affect life expectancy, causing premature deaths months to years later.

Lessons from past pandemics

After the 1918 flu, the scientific literature of the time described rare cases of brain fog and chronic fatigue, two of the symptoms associated with Covid-19 today. But in addition to the usual symptoms of the flu, the 1918 flu left a very worrying sequel with delayed effects: a wave of heart attacks that shook the world between 1940 and 1959. That wave was strange, apparently inexplicable, but today we already know that was associated with the previous influenza pandemic. The virus had left a time bomb in some survivors.

This wave of cardiovascular diseases especially affected men, just like the flu pandemic itself and now that of Covid-19. As a possible explanation, it has been proposed that the unusual immune response in men between 20 and 40 years of age in 1918 could have conditioned the survivors to suffer greater mortality in adulthood.

But what’s more, prenatal exposure to the 1918 flu virus has been associated with a greater chance of suffering from cardiovascular disease after the age of 60.

Subsequent studies have shown that influenza virus infection increases the development of atherosclerotic plaques and, therefore, the possibility of suffering heart attacks. Damage to the vascular endothelium accelerates the formation of plaques and, therefore, the risk of heart attacks.

SARS-CoV-2 infection and cardiovascular disease

After the first months of the pandemic, data began to be collected indicating an increase in cardiovascular damage after infection with SARS-CoV-2. The most frequent complications were heart failure, myocardial damage, arrhythmias and acute coronary syndrome.

To explain these symptoms, two possibilities are considered and both are based on consistent evidence:

1. A imbalanced immune response against viral infection causes an inflammatory process that causes vascular damage. Inflammation, whose maximum exponent is the cytokine storm, would cause vasculitis, or vascular inflammation. Thus, in people who already have the onset of cardiovascular disease, this inflammation would accelerate the process.

   This would explain why the people most affected by Covid-19 are those with cardiovascular problems and risk factors such as diabetes, hypertension and hypercholesterolemia.

2. SARS-CoV-2 enters cells using the ACE2 protein, which is highly present in endothelial cells that line blood vessels. This protein is essential for the functioning of the cardiovascular system, regulating blood pressure, electrolyte control, vessel repair and inflammation.

   Thus, if the virus reaches the blood, it will invade these cells, causing endothelial damage accompanied by inflammation, leading to vasculitis and thrombosis, two of the symptoms of infection. In addition, the S protein itself generates inflammation signals in the endothelial cells, further aggravating the situation.

Increase in abortions in women suffering from covid-19

As SARS-Cov-2 affects the endothelium, it is very possible that it causes irreparable damage to highly vascularized tissues, including the placenta.

This explains the increase in abortions produced in women who have suffered covid-19. In fact, the profiles of vascular damage in pregnant women with Covid-19 are similar to those found in cases of preeclampsia, a blood pressure imbalance that causes vascular damage and miscarriages.

In addition, other studies have shown that in early pregnancies the virus can cause damage to the organs of the fetus associated with a generalized inflammatory process.

Vaccines and myocarditis? no evidence

The effect of protein S on the endothelium has been linked to possible vascular damage caused by mRNA-based vaccines. In these vaccines, the mRNA they contain generates this protein in the tissues so that the immune system recognizes it and activates against it. But this damage could not be proven.

Although attempts are made to raise alarm about vaccine-associated myocarditis, scientific data does not support this fear. A recent post on JAMA has shown that of some 192.5 million vaccinated in the US, only 8.4 people per million presented symptoms of myocarditis, of which only 92 people needed more specific treatments than the usual anti-inflammatory drugs and none of them died.

There is no reason for so much alarmism. The symptoms of myocarditis reported a few days after vaccination are mild and probably indicate a somewhat more aggressive inflammatory response in these people, but not direct protein S damage. In fact, protein S levels in the blood after vaccination are very low and its effect on the endothelium is transient, disappearing in a few days.

Prevention of vascular damage, one more reason to get vaccinated

With all the data accumulated to date and the precedents of previous pandemics, we can conclude that Covid-19, like other acute respiratory infections, can worsen cardiovascular diseases and reduce life expectancy either by accelerating vascular damage or by generate new damage. This damage can end up causing death even months or years after infection.

Fortunately, vaccination has been shown to be effective against these effects as well as against Covid-19. The rationale is simple: if the virus cannot reach the blood, it cannot affect the cardiovascular system.

One more reason not to let the coronavirus infect us without being prepared. Vaccination saves lives, even years later.

Guillermo López Lluch, Professor of the Cell Biology area. Associate researcher at the Andalusian Center for Developmental Biology. Researcher in metabolism, aging and immune systems and antioxidants, Pablo de Olavide University

This article was originally published on The Conversation. Read the original.