Of course, we are all solidly aware of SARS-CoV2 (the virus) and COVID-19 (the disease that it causes); a medical consideration that didn’t exist a couple of years ago. For most of us, COVID-19’s main symptoms are respiratory and, although the virus is sometimes challenging, we usually recover within a few weeks.

However, for some, the effects of COVID-19 are long-lasting.

What is long COVID?

Termed “long COVID”, the disease can lead to a huge range of symptoms that affect the respiratory, neurological, and gastrointestinal systems, with symptoms potentially lasting for months (or even years, in some cases)^{1, 2}. There are currently over 100 acknowledged symptoms of long COVID. As well as physical impairments, people can be left with “brain-fog”-type problems in thinking and processing information as well as an emotional legacy including depression and anxiety symptoms^{2, 3}.

How does long COVID influence the brain?

How long will COVID last?

Research is still being undertaken to determine how long COVID works to affect people, but medical professionals do know that the receptors by which SARS-CoV2 enters cells are present in the brain, leaving the possibility that the virus can directly enter our brain cells. We also know that the body’s immune response, if severe enough, can damage our brains^{4, 5}.

One of the few studies to look at how our brains might be damaged with long COVID suggests there is less activity in the cingulate cortex than there should be. The cingulate cortex is involved in many cognitive functions including in processing emotions and memory, so less activity in this area could account for the impairments³. Other studies have seen similarly depressed activity in limbic regions and the hippocampus, which are also important for emotion and memory.

A working theory still being investigated suggests that the virus may directly access the brain at the olfactory bulb (via the nose) – here, the virus may damage the olfactory bulb and destroy neurons that lead back to the rest of the brain⁶. Over time, scientists will work to determine the validity of this theory, and this could potentially lead to better outcomes for everyone affected by long COVID.

Does long COVID affect children?

Importantly, children are not immune. Data have been released from the first major study of long-COVID in children (aged 6-16) and these suggest that more than half of those who contracted SARS-CoV2 exhibited symptoms that lasted longer than 120 days, with 43% being impaired on a day-to-day basis by these symptoms⁷. Other studies suggest there are multiple lasting symptoms in more than 10% of children⁸. Clearly, long COVID can affect our younger generations too.

So, what do we do to prevent long-COVID in children?

It is clearly essential that we do not ignore children’s health in this pandemic. As per the recommendations for adults, we should employ safety measures such as social distancing in public places and COVID testing for children, too.  We need to consider COVID-19 in children for the potential health risk that it is.

Currently no vaccine has been generally approved for use in very young children, although options are still being explored. Vaccinating adults, though, will reduce the likelihood of the virus’ spread and reduce the chances that we pass it on to our children. It is also essential that we study this virus in children as we do in adults so that we can understand the breadth of the possible damage going forward.

References

1. Carfi A, Bernabei R, Landi F, Gemelli Against C-P-ACSG. Persistent symptoms in patients after acute covid-19. JAMA. 2020;324:603-605
2. Sudre CH, Murray B, Varsavsky T, Graham MS, Penfold RS, Bowyer RC, et al. Attributes and predictors of long covid. Nature medicine. 2021;27:626-631
3. Hugon J, Msika EF, Queneau M, Farid K, Paquet C. Long covid: Cognitive complaints (brain fog) and dysfunction of the cingulate cortex. J Neurol. 2021
4. Boldrini M, Canoll PD, Klein RS. How covid-19 affects the brain. JAMA Psychiatry. 2021;78:682-683
5. Ellul MA, Benjamin L, Singh B, Lant S, Michael BD, Easton A, et al. Neurological associations of covid-19. Lancet Neurol. 2020;19:767-783
6. Guedj E, Morbelli S, Kaphan E, Campion JY, Dudouet P, Ceccaldi M, et al. From early limbic inflammation to long covid sequelae. Brain : a journal of neurology. 2021
7. Buonsenso D, Munblit D, De Rose C, Sinatti D, Ricchiuto A, Carfi A, et al. Preliminary evidence on long covid in children. Acta Paediatr. 2021;110:2208-2211
8. Osmanov IM, Spiridonova E, Bobkova P, Gamirova A, Shikhaleva A, Andreeva M, et al. Risk factors for long covid in previously hospitalised children using the isaric global follow-up protocol: A prospective cohort study. Eur Respir J. 2021

from an Expert Author

Sarah J. Spencer

BSc Hons, Ph.D –Neuroscientist

Sarah Spencer is a Professor of Neuroscience of RMIT University. She has around 16 years’ experience investigating the impact of the perinatal environment on brain and behaviour. She has a particular interest in the brain’s immune system and how it governs neurological function.

She completed her undergraduate in Physiology at Otago University in New Zealand and then a PhD in 2004 in Neuroscience at the University of Queensland. She followed this with a three-year postdoc at Calgary University in Canada, studying how exposure to immune challenges in critical programming windows of early life lead to long-term changes in immune regulation and the brain. She then moved back to Australia to Monash University and then RMIT University in Melbourne where she leads her team in the investigation of perinatal programming of long-term brain function.

Sarah has authored and co-authored around 100 scientific publications, including two translating primary scientific studies into articles for children. She is an Associate Editor of one of the top neuroscience journals, Brain Behavior and Immunity, and an Academic Advisory Board member for the Sanfilippo Children’s Foundation, promoting scientific research into this devastating childhood disease.

See author's posts