With COVID-19 cases rising in the young population, the Centres for Disease Control and Prevention (CDC) has a clear message for all adults: when it comes to age, there is no bright line for risk.
There is not an exact cutoff of age at which people should or should not be concerned. After analysing cases across the United States, the CDC announced updates to the characteristics that seem to leave people vulnerable to the worst COVID-19 outcomes: hospital stays, intensive care, and death.
The risk from a COVID-19 infection increases with advancing age. In general, people in their 50s are at a higher risk than people in their 40s. Likewise, people in their 60s and 70s are at a higher risk than those who are in their 50s.
Conditions in which there is strong evidence of increased risk include chronic kidney disease, chronic obstructive pulmonary disease (COPD) like emphysema, people with lower immune health because of a solid organ transplant, obesity - those with a BMI greater than 30, serious heart conditions like heart failure and coronary artery disease, sickle cell disease and type 2 diabetes.
Conditions that might place a person at a greater risk for a severe outcome from COVID-19 are asthma, dementia, cerebrovascular diseases such as stroke, cystic fibrosis, high blood pressure, lower immune health, pregnancy, liver disease, scarring in the lungs (pulmonary fibrosis), smoking, type 1 diabetes and thalassaemia.
Jay Butler, Deputy Director of infectious diseases at CDC, said hypertension had been moved to the list of conditions that could place a person at increased risk because they had learned more about the role of hypertension, on its own, and some of the things that hypertension can lead to, like kidney damage and heart disease.
"We have been able to tease apart a little more how much just having hypertension alone, as opposed to having some of those end-organ manifestations of hypertension, might be driving the increased risk," he said.
Obesity, in contrast, seemed to be its own, independent risk, even apart from other health conditions that may also happen in people who are obese, like diabetes.
A new study by the CDC showed that pregnancy can make the course of COVID-19 more severe for women, though it does not seem to increase their risk of death.
In a study that compared COVID-19 outcomes among women between the ages of 18 and 44 by pregnancy status, nearly one-third of the pregnant women were hospitalised for their infections, while only about 6% of the non-pregnant women had to be admitted to the hospital.
Pregnant women were also more likely to need ICU care and to receive breathing support from a ventilator, but they were not more likely to die. About 0.2% of both pregnant and non-pregnant women died of COVID-19 during the study period.
Study authors stress that women who are pregnant during the pandemic should take extra care by staying at home whenever possible, wearing a mask in public, standing or sitting at least 6 feet away from others when they do have to go out, and washing their hands often.