The US Trump administration will this week announce a plan to cover out-of-pocket costs of Covid-19 vaccines for millions of Americans who receive Medicare or Medicaid,

US infectious disease expert Anthony Fauci said on Sunday it would be clear whether a Covid-19 vaccine was safe and effective by early December, but that more widespread vaccination would not be likely until later in 2021.

German biotech company CureVac said on Friday its potential vaccine against the coronavirus induced an immune response in pre-clinical animal studies.

The Korea Disease Control and Prevention Agency (KDCA) said on Friday it would not halt a wide flu vaccination programme aimed at heading off complications from the coronavirus, after reviewing more than two dozen cases of deaths that have raised public concern.

Indian Prime Minister Narendra Modi on Tuesday said the government was preparing to supply Covid-19 vaccines to all citizens once they are available.

Spain would receive 31.6 million doses of the Covid-19 vaccine currently being developed by Britain's pharmaceutical giant AstraZeneca between December and June if it is ready, Health Minister Salvador Illa said on Tuesday.

Scientists called for urgent action to improve public trust in immunisation as research suggested sizeable minorities in some nations may be reluctant to be vaccinated against Covid-19.

Britain said on Tuesday it would back "human challenge" trials, where young and healthy volunteers are deliberately infected with Covid-19, to accelerate the development of vaccines for the disease.

A row broke out on Friday over a World Health Organization (WHO) clinical trial which concluded that the anti-viral drug remdesivir has little or no impact on a patient's chances of surviving Covid-19.

The US Centers for Disease Control and Prevention (CDC) said on Wednesday that Covid-19 vaccines may not be initially recommended for children, when they become available.

The US Food and Drug Administration made public its guidance for issuing emergency approval for a Covid-19 vaccine on Tuesday, making it clear it wants to see follow-up two months after trial volunteers have their second dose.

A Chinese experimental coronavirus vaccine being developed by the Institute of Medical Biology under the Chinese Academy of Medical Sciences was shown to be safe in an early stage clinical trial, researchers said.