Reacción a "Reactions: persistent covid studies have created misunderstandings because of their limitations, says analysis"

The authors of this study usefully point out that because the umbrella term Long COVID is a broad definition, it's challenging to design population studies that give a precise measure of Long COVID prevalence in a population. The discussion about pitfalls in study design is good. But this paper is highly selective in terms of the studies that the authors choose to highlight.
 
The lead author Høeg is linked with think tank groups that have been strongly advocating against public health measures throughout the Covid-19 pandemic. These links may explain the more optimistic view of this author group about Long COVID risks.
 
The authors have omitted to mention that alongside population surveys there is an extensive and active field of research to understand the impacts of this virus on the body. The science about longer-term effects of Covid-19 infection is now very much better understood than it was even a year ago. The research shows that COVID-19 is a multisystem disease that can cause microclots, changes to the immune system, viral persistence in tissues, and other effects even in mild cases; this major paper in Nature Reviews Immunology provides a detailed and recent overview. These effects are the basis for well-described longer-term effects of COVID-19 such as impaired brain function, extreme fatigue, and stroke. These tissue-level effects can also be silent (causing no symptoms) but they are known risk factors for heart disease and other conditions, raising concerns for population health in the future, with potentially large numbers of people experiencing poor health in years to come.
 
Even the research that is mentioned in this article is not as reassuring as the article seems to suggest: 

• Antonelli et al. reported lower risk of Long COVID for Omicron compared with Delta infection, depending on age and time since vaccination. But they noted that Omicron variants have caused far higher case numbers and the conclusion of their article is that 'future numbers with Long COVID will inevitably rise.'
• Studies that use serology to identify past infection have an important limitation that some people (including children) don’t produce long-lasting antibodies despite having had the infection, leading to unreliable results in Long COVID research.
• Studies using ONS data are not designed to detect and measure the longer-term effects that are described in other research.

All pandemics and major epidemics cast a long shadow of chronic disease that can continue to emerge decades after the initial emergency phase. In 2023 we are still experiencing high levels of COVID-19 infection and reinfection in Aotearoa New Zealand. Reducing COVID-19 infection rates is still the only reliable way to reduce the longer-term impacts on population health.