Scientists still aren't clear where it came from, and they are still trying to understand what causes long-term symptoms called long COVID. 


<div class="paywall-container">
<div class="textbox">
<h4 style="padding: 0 0 20px"> <a href="https://checkout.bostonherald.com/?&amp;g2i_or_o=Internet&amp;g2i_or_p=mg2pw20&amp;g2i_source=MD&amp;g2i_medium=sspw&amp;g2i_campaign=MG2PW20-sspw&amp;returnUrl=https3A2F2Fwww.bostonherald.com2F">Subscribe</a> to continue reading this article.</h4>
<h4> Already subscribed? <a href="https://www.bostonherald.com/login?&amp;returnUrl=https%3A%2F%2Fwww.bostonherald.com%2F2025%2F01%2F02%2Fcovid-5-years-later%2F">To login in, click here.</a></h4>
</div>
</div>


Originally Published: <time datetime="2025-01-02 11:21:00">January 2, 2025 at 11:21 AM EST</time>

Scientists still aren’t clear where it came from, and they are still trying to understand what causes long-term symptoms called long COVID.{ai:summary}<p>Scientists continue to investigate the origins of long COVID and the factors contributing to its long-term symptoms. Research is ongoing to better understand this complex condition. #health</p>

5 things we know and still don’t know about COVID, 5 years after it appeared

Subscribe to continue reading this article.

Already subscribed? To login in, click here.

Loading...