The mRNA vaccines do not contain any live virus. Instead, they work by teaching our cells to make a harmless piece of a “spike protein,” which is found on the surface of the virus that causes COVID-19. After making the protein piece, cells display it on their surface.
(Individuals who get an mRNA vaccine are not exposed to the virus, nor can they become infected by the vaccine.) Using this mRNA blueprint, cells produce the viral protein. As part of a normal immune response, the immune system recognizes that the protein is foreign and produces specialized proteins called antibodies.
Not only are the vaccines safe for people with a history of heart disease, they are essential. People with heart disease are at increased risk of severe complications from COVID-19.
“Some people who were infected with COVID-19 have experienced heart inflammation as a complication. More recently, heart inflammation has surfaced as a rare side effect after COVID-19 vaccination.”
Myocarditis is inflammation of the heart muscle, and pericarditis is inflammation of the outer lining of the heart. In both cases, the body's immune system causes inflammation in response to an infection or some other trigger.
While there isn't specific data on this, COVID-19 is primarily a respiratory virus but patients with vascular disease need to very wary of COVID-19 infection. Diagnosed vascular diseases are considered underlying health conditions that could predispose patients to a worse outcome if infected.
COVID-19 is a disease caused by SARS-CoV-2 that can trigger what doctors call a respiratory tract infection. It can affect your upper respiratory tract (sinuses, nose, and throat) or lower respiratory tract (windpipe and lungs).
COVID-19 can make blood cells more likely to clump up and form clots. While large clots can cause heart attacks and strokes, much of the heart damage caused by COVID-19 is believed to stem from very small clots that block tiny blood vessels (capillaries) in the heart muscle.
COVID-19 does appear to affect brain function in some people. Specific neurological symptoms seen in people with COVID-19 include loss of smell, inability to taste, muscle weakness, tingling or numbness in the hands and feet, dizziness, confusion, delirium, seizures, and stroke.
Some neurological symptoms in the lower limbs and feet have also been noted amongst COVID-19 patients, with Guillain-Barré Syndrome occurring in those aged over 60 in particular.
In some people, response to the coronavirus has been shown to increase the risk of stroke, dementia, muscle and nerve damage, encephalitis, and vascular disorders. Some researchers think the unbalanced immune system caused by reacting to the coronavirus may lead to autoimmune diseases, but it's too early to tell.
Meanwhile, COVID-19 itself can lead to neurological and mental complications, such as delirium, agitation, and stroke. People with pre-existing mental, neurological or substance use disorders are also more vulnerable to SARS-CoV-2 infection ̶ they may stand a higher risk of severe outcomes and even death.
The most comprehensive molecular study to date of brain tissue from people who died of COVID-19 provides clear evidence that SARS-CoV-2 causes profound molecular changes in the brain, despite no molecular trace of the virus in brain tissue.