Can the COVID vaccine make Long Covid worse?

vaccines protect against long COVID
As a long hauler, you must have had to make a difficult decision every time you have been offered a follow-up Covid vaccine. The question you have no doubt asked is, ‘Can the Covid vaccine make my Long COVID worse?’

How Well Do Covid vaccine Protect Against Long COVID

How does the Covid vaccine effect long Covid? – Can it make me worse? And what about re-infection? – Here is what you need to know.

Getting a Covid-19 infection can be a terrifying experience but living with long Covid or what doctors sometimes refer to as “Post-Covid Syndrome”, can be equally frightening. Long Covid is when the acute symptoms, such as a temperature, shortness of breath, a violent cough and flu-like symptoms, of your Covid infection have calmed down, but you are still experiencing some symptoms weeks or months later. Long Covid usually begins four or more weeks after the ‘recovery’ from Covid and may last for months or even years (1).

What Is Long COVID

 Study shows Covid vaccine reduces the risk of long Covid by 15%

It is still unclear why some people experience long Covid after their initial infection despite huge research programmes to uncover new insights into the situation. A huge study published in the journal Nature in May 2022 showed that vaccination lowers the risk of getting long-Covid by 15% (2). However, if you already have long Covid, you will be more interested to know whether vaccines whether the Covid vaccine is likely to have a positive, negative or no effect on your existing symptoms.  Keep reading to find out more about this question.

Does the Covid vaccine make long Covid worse or better?

While research so far suggests that vaccination slightly reduces the risk of long-Covid for people who have not been infected before they have it, the results are rather conflicting as to whether it improves long Covid symptoms or worsens them in people who have the vaccine when already suffering from long Covid. It appears that the vaccine improves symptoms in some people, aggravates them in others and has no effect on symptoms in most. For example, Akiko Iwasaki, Professor of Immunobiology at Yale School of Medicine, found that  30 – 40 percent of people reported an improvement in their long Covid symptoms, such as brain fog, gastrointestinal problems or shortness of breath (3).

“The vaccine against Covid-19 may reset a person’s immune system,” he says, “and help the immune system eliminate the residual virus or stop a harmful immune response that results in long-Covid symptoms.” However, “Nearly 10 to 15 percent of the people with long Covid feel worse after getting the Covid vaccine,” notes Professor Iwasaki.

Other evidence suggests that vaccination proves helpful against long Covid. For example, a french study involving 910 adults with long Covid showed that vaccination resolved long Covid symptoms in twice as many people as those who remained unvaccinated. In addition, the Covid vaccine also reduced the severity of long-Covid symptoms as well as its impact on life quality (4).

A UK study involving 6729 adults with long Covid investigated the relationship between vaccination and the symptoms of long Covid. The researchers found a 12.8 percent reduction in long Covid symptoms immediately after the first dose, but the results were not sustained over the following weeks. However, the second dose led to a sustained reduction of 8.8 percent in long Covid symptoms, indicating the relevance here of two doses instead of one (5).

A study published in the Journal of Medical Virology compared antibody titers pre and post-vaccination among 42 people with long Covid. After vaccination, long Covid was relieved in 16.7 percent of the participants; it worsened in 21.4 percent and remained unchanged in 61.9 percent. The researchers noted that participants with the highest antibody titers post-vaccination experienced a worsening of their long Covid symptoms, indicating the immune response to be the underlying cause of long Covid (6).

A literature review published in the peer review journal The Lancet, reviewed eleven research papers on the effects of the vaccine on long Covid. While the criteria used were different for each study, seven studies reported an improvement in long Covid at least one dose after the vaccination. However, the researchers of the other four studies saw either no change in participants with long Covid or a worsening of their symptoms (7).

Thus, the results remain conflicting. While most studies report an improvement in long Covid symptoms, others say their participants ended up with long Covid that was worse than before vaccination.

How does the Covid vaccine effect long Covid?

Since there is no clear understanding of why long Covid occurs in the first place, researchers also don’t know the relationship between the vaccine and long Covid. Unfortunately, therefore, at the time of writing, not enough research has been done to conclude whether a Covid vaccine would improve, have no effect or worsen the condition in any individual case. You might be lucky and be one of those who see an improvement, but you may be unlucky and be someone who is made worse by the vaccine. As always, with Covid and long Covid, everyone is different, which is why the whole story of Covid and what it does to us is going to be a very, very long one.


Some doctors believe that Covid infection leads to an abnormal immune response, in which the immune system attacks not only the virus but also normal body parts, such as the heart, brain and muscles. Professor Iwasaki of Yale School of Medicine notes that it is possible that the vaccine resets the immune system, strengthens it against the virus or prevents it from potentially damaging the organs of the body. In addition, he believes that if residual viral load is involved in the pathology of long Covid, the vaccine may help eliminate it.

Furthermore, since the Covid vaccine elicits a strong immune response against the virus, it may also exacerbate long Covid if a hyperactive immune response is to blame. In addition, the types of covid vaccines bring positive or negative changes in only a small percentage of people suffering from long Covid, as described in studies mentioned above. As a result, its potential benefits or adverse consequences should not stop a person with long Covid from getting the Covid vaccine.



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