The emergence of the new COVID JN1 variant has raised concerns. Should this be a cause for worry? Like the regular flu, new variants of COVID-19 will continue to surface periodically. Three critical aspects to consider are the rate of transmission, its responsiveness to existi...

A year ago, just two doses of a Covid-19 vaccine — or even one, in the case of Johnson & Johnson’s formulation — were thought to offer sufficient protection against the coronavirus. Now, faced with the extraordinarily contagious Omicron variant, Israel has begun offering f...