US regulators on Tuesday confirmed that the Pfizer/BioNTech Covid vaccine was 95% effective, paving the way for it to be approved for emergency use.
The FDA found no safety concerns to stop approval of the vaccine.
Although two doses are needed to offer full protection, the first jab prevented 89% of the most severe cases. Some side-effects such as redness or swelling at the injection site, short-term fatigue, headaches and muscle-pain were reported but were considered mild.
US biotech firm Moderna has reported similar successes with its vaccine and it is also expected to get FDA approval before Christmas.
Estimates of the cost of both vaccines are in-line with the flu jab, which is about $40 (£30) per person in the US. Mr Trump’s government is taking steps to provide the vaccine at no cost to elderly people and those who receive government assistance for healthcare costs, according to the Centers for Medicare & Medicaid Services (CMS).
Meanwhile, the coalition People’s Vaccine Alliance warned that rich countries were hoarding doses of Covid-19 vaccines and people living in poor countries were set to miss out.