The Biden administration, keeping a watchful eye on an outbreak of avian influenza that has led to the deaths of tens of millions of chickens and is driving up the cost of eggs — not to mention raising the frightening specter of a human pandemic — is contemplating a mass vaccination campaign for poultry, according to White House officials.

Experts at the Centers for Disease Control and Prevention, whose focus is human health, say the risk of a pandemic is low. As a precaution, the agency has sent drug manufacturers flu virus samples that could form the basis of vaccines for people.

C.D.C. is also exploring whether commercial test manufacturers would be willing to develop tests for H5N1, similar to those used for the coronavirus.

Cases typically involve people exposed to poultry. In the United States, the C.D.C., in partnership with state and local public health departments, is monitoring people who are exposed to H5N1.

As of last week, 6,315 people had been monitored; 163 reported symptoms; and one tested positive, according to Dr. Tim Uyeki, the chief medical officer of the C.D.C.’s influenza division.

At the same time, officials at the federal Agriculture Department, which is responsible for the health of farm animals, say they have begun testing potential poultry vaccines and initiated discussions with industry leaders about a large-scale bird flu vaccination program for poultry, which would be a first for the United States.

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