Many COVID ‘long-haulers’ report improvement after vaccination

March 2021 Corona Willem van Altena

Long covid. That is the term that is used to describe the after effects of a COVID-19 infection that sometimes linger for weeks or even months after the acute phase of the disease has passed. The phenomenon started to manifest itself in the summer of 2020 when an increasing number of COVID-19 patients reported fatigue, dyspnoea and many other sometimes crippling symptoms, long after the virus had left them. Remarkably, these long lasting effects seem to occur more in younger patients, and in patients who suffered a relatively mild form of COVID-19. A lot is still unknown about this possibly emerging new illness, but numerous studies indicate that one in every three COVID-19 patients may suffer from long covid. However, now that the vaccination programmes are underway, there are more and more reports from long covid-sufferers whose condition rapidly improved after being inoculated.


The first reports of ‘long-haulers’ reporting feeling better after being vaccinated came from the USA, where all healthcare workers are being vaccinated, including those who had already had COVID-19. Among these, a number of healthcare workers suffered from long covid and many of them claim they started feeling better within hours of being vaccinated.

A small study from Bristol (UK) seems to confirm this. In this study, that has been published on science website medXriv ahead of peer review, 66 long covid patients were followed, 44 of whom received vaccination. Almost a quarter of them felt better as a result and experienced less dyspnoea and joint pain. However, 5,6% of the vaccinated patients felt their condition worsened as a result. It did not seem to matter which vaccine the people had received.

Virus remnants

More research is needed to establish a link between the vaccine and its effects on long covid, and how this link can be explained. One theory is that after the acute phase of the infection has passed, remnants of the dead virus remain in the body with some patients, and these can trigger a prolonged immune response, such as fever and fatigue. A vaccination could slow the immune system down and prompt the production of more antibodies and T-cells that can get rid of residual virus traces.

Meanwhile, long covid has not officially been defined in a clinical or diagnostic sense. There are many symptoms that can be associated with long covid, such as fatigue, dyspnoea and insomnia, along with loss of sense of smell and taste. Many sufferers also mention fever, clotting issues and neurological symptoms such as loss of concentration and brain fog.


De term ‘long covid’ seems to be the most widely accepted name for the affliction, but some medical professionals prefer the acronym PASC, which stands for ‘Post Acute Covid Sequelae’. In Belgium, so far there has not been official research into long covid and there is no federal response to this condition. In the Netherlands, the government funds an initiative where people who have been suffering with covid after effects for 3 months or more can come into contact with special councillors who seek to help them in a medical as well as non-medical way.


D Arnold, A Milne, E Samms et al, Are vaccines safe in patients with Long COVID? A prospective observational study.doi: (Niet peer-reviewed onderzoek, nog niet gepubliceerd)