The timing of symptom onset depends on lots of factors, including the amount of virus to which someone was exposed, Hotez says. Their level of pre-existing immunity may also affect the likelihood or ...

Such knowledge could be particularly useful when it comes to COVID-19. Granted, the symptoms of the latest Omicron variants don’t tend to be severe, but testing positive means isolating for several ...

Researchers are looking at data from U.S. cases to determine if the variant causes milder disease. Even if the answer is yes, they say, rates of... What we know about the symptoms — and the severity — ...