Health

Companies focus on safety, immune response to vaccines in children and teens

But outside experts warn sample sizes are small and call for more data

Panel advice on vaccines could counteract legacy of mistrust from past health scandals

First human COVID-19 challenge studies can proceed despite known risks, ethics board says

Growing toll on fragile health systems prompts calls for more global equity

Bluebird bio, developer of the gene therapy, is evaluating whether a virus used could have triggered cell growth

The shots are beginning to have a societal impact, but herd immunity is a distant dream

Students’ parents and teachers’ spouses had a lower increase in risk, according to detailed Swedish health registry

Lab accident hypothesis, though “extremely unlikely,” has not been ruled out, Peter Ben Embarek says after returning from 4-week investigation

Scarce vaccine supplies ramp up interest in combining different doses

Tocilizumab, antibody also used for rheumatoid arthritis, saves patients’ lives by dampening the immune system

Reversing “stress” in a crippled cell organelle could help people with Wolfram syndrome, and other illnesses with the same flaw

Plans to track rapidly evolving viral strains are not ambitious enough, some scientists say

Small efficacy trial doesn’t show whether vaccine may prevent severe disease caused by antibody-dodging strain

The reptiles make poor hosts for transmitting the infection

Some say the country should reopen—even if it causes cases to surge—once vulnerable populations are vaccinated