Upcoming flu outbreaks will be less predictable than those of the past.
In a study of 43 men who had recovered from COVID-19, nearly 20% had azoospermia, or the total absence of sperm in semen.
Mouse sperm carrying a genetic sequence called the t-haplotype will poison their competitors, then make an 'antidote' only for themselves, new research finds.
Amid a shortage of vaccine supplies and the threat of emerging coronavirus variants, such an approach might provide an answer for both.
The brains of people with depression have fewer astrocytes, a type of brain cell, according to a small study.
Called xylazine, the drug is a sedative used in veterinary medicine, and is not approved for use in humans.
Experts are particularly alarmed by this variant because of its potential to "escape" protection from current vaccines.
People's heartbeats may stop and restart as they die, with implications for the practice of organ donation.
The vaccine's efficacy was highest in the U.S. and the lowest in South Africa, where a new variant is infecting people.