The US Centers for Disease Control and Prevention (CDC) has asked state public health officials to prepare to distribute a potential coronavirus vaccine to high-risk groups as soon as late October or early November, documents published by the agency showed on Wednesday.
The timing of release of any vaccine has taken on political importance as US President Donald Trump seeks re-election in November, after putting substantial federal resources into vaccine development.
"For the purpose of initial planning, CDC provided states with certain planning assumptions as they work on state specific plans for vaccine distribution, including possibly having limited quantities of vaccines in October and November," a CDC spokeswoman told Reuters.
The New York Times had earlier reported that the CDC had contacted officials in all 50 states and five large cities with the documents.
The country's top infectious disease expert Anthony Fauci earlier on Wednesday said on MSNBC that based on the patient enrollment rate in COVID-19 vaccine trials underway, there could be enough clinical data to know by November or December that one of the vaccines is safe and effective.
The documents put online by the New York Times showed that the CDC is preparing for one or two vaccines for COVID -19 to be available in limited doses as soon as late October.
The vaccines may be available free of cost first to high-risk groups including health care works, national security personnel, residents and staff at COVID-19 long-term care facilities, the agency said in the documents.
Drug developers including Moderna Inc, AstraZeneca Plc and Pfizer Inc are leading the race to develop a safe and effective vaccine for the respiratory illness.
The documents describe two vaccine candidates that must be stored at temperatures of -70 and -20 degrees centigrade. Those storage requirements match profiles of candidates from Pfizer and Moderna.