Mr Biden would be isolating at the White House “consistent with CDC guidelines.”
An additional 54,530 third-generation vaccine doses have been purchased from Bavarian Nordic, according to the European Commission.
The agreement was signed with Biotechnological and Pharmaceutical Industries, a business arm of the Cuban government.
“Africans’ over-dependency on foreign countries is dangerous to the health of everyone, especially children,” the virologist said.
They said protection against infection was two times higher in those vaccinated four times than in three.
The donation brings the total number of vaccine doses donated to Nigeria by the British government to 1,292,640.
A official said the postponement was due to some unforeseen circumstances.
The United Kingdom has taken off the COVID-19 travel advisory warning for Nigeria.
The DG said vaccine nationalism is an ineffective public health strategy against a respiratory virus that is mutating quickly and becoming increasingly successful at infecting new hosts.
A spokesman of NCDC described the sale of the vaccine as “crazy”.