{"id":35121,"date":"2024-09-30T07:00:49","date_gmt":"2024-09-30T07:00:49","guid":{"rendered":"https:\/\/updates-www.mccdn.io\/vitals\/?p=35121"},"modified":"2025-11-19T23:36:43","modified_gmt":"2025-11-19T23:36:43","slug":"what-have-we-learned-about-covid-19","status":"publish","type":"post","link":"https:\/\/updates-www.mccdn.io\/vitals\/what-have-we-learned-about-covid-19\/","title":{"rendered":"What have we learned about COVID-19?","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"

When the virus that causes COVID-19 sparked a global pandemic in 2020, questions about this pathogen far exceeded answers. How does it spread? Can we get it from contaminated objects or surfaces? Why do some people get really sick when others don\u2019t?<\/p>\n

While some mysteries remain, there is also a lot we have learned about COVID-19 since it upended our lives four years ago \u2014 from how it transmits to how long immunity is likely to last. In this two-part series<\/a>, find out what we know now about COVID-19.<\/p>\n

Why COVID-19 affects people differently<\/strong><\/h2>\n

Some people with a COVID infection experience cold-like symptoms that last a few days, while others may be ill for weeks or even require hospitalization. There are many factors that influence how sick a person gets.<\/p>\n

People 50 and older or those with an underlying medical condition, like diabetes or heart disease, are at higher risk of experiencing severe illness. This is because their immune systems may have more difficulty fighting the virus.<\/p>\n

How sick you get also depends on your viral load \u2014 the amount of virus particles in your body. If the viral load is minimal, your immune system may be able to clear the virus quickly and you may experience few or no symptoms. If your viral load is high, you\u2019re more likely to experience severe symptoms for longer.<\/p>\n

Perhaps the biggest factor shaping our experience with COVID-19 that we have control over is vaccination status.<\/p>\n

\u201cSeveral studies have now shown how effective the vaccines are at reducing the severity of infections and preventing both hospitalizations and deaths,\u201d says Mary Fairchok, MD, a pediatric infectious disease specialist<\/a> at MultiCare Mary Bridge Children\u2019s Hospital<\/a>.<\/p>\n

A study published in The Lancet<\/a> that collected COVID-19 data in Europe through March 2023 found that the vaccines saved 1.6 million lives and reduced deaths by 59 percent.<\/p>\n

How some people seem to avoid infection<\/strong><\/h2>\n

Most of us by now have had a COVID-19 infection at least once, but there are people, sometimes referred to as \u201csuperdodgers,\u201d who have never tested positive or developed symptoms. This is likely, in part, due to individual habits and behaviors.<\/p>\n

\u201cIf you managed to avoid COVID early on in the pandemic and got vaccinated, then there\u2019s a high chance that at some point after vaccination, you may have actually gotten infected, but it was so mild you didn\u2019t notice or test positive,\u201d Dr. Fairchok says.<\/p>\n

Biology and genetics may play a role, too. A study published in Nature<\/a> found that some people who were exposed to the virus experienced abortive infections, meaning they never developed symptoms or tested positive. There were two notable aspects about this group of study participants:<\/p>\n