'We need collectively to be rethinking what is the goal of vaccination,' doctor says, as shots prove effective at saving lives but not in preventing spread of new variants

'The public can be assured that this vaccine was approved in keeping with the FDA’s rigorous scientific standards,' says senior regulator

Research dashes hopes that new boosters will deliver Omicron-proof protection, but they may still help the elderly and at-risk by reducing chances of serous illness

Officials say shorter wait time could help as US struggles with Omicron surge, call vaccination 'our best defense against COVID-19'

Drugmaker says lab tests show half-dose booster shot increased by 37 times the level of so-called neutralizing antibodies able to fight new strain of coronavirus

Research carried out by NIAID, Moderna and other institutions showed vaccine was safe and effective against an HIV-like virus

Stephane Bancel says there's 'no world' in which protection will prove to be the same against new strain, says he expects a 'material drop'

US follows Israel's lead and places emphasis on those aged 50 and above, urging older populations to get extra shot; expansion makes tens of millions more Americans eligible

Decision still needs CDC approval for Pfizer and Moderna vaccines, with panel to meet later Friday, amid rising cases and fears of a fresh virus wave in winter

FDA says review could last until January; pharma company also delays filing authorization request for lower dose of the vaccine for 6- to 11-year-olds