Margaret Chan, WHO director-general, was vaccinated on Dec. 30, a day after admitting at a news conference that she had not got round to it due to travel and other demands.
She is feeling very well, working and very busy as usual, WHO spokeswoman Fadela Chaib told a news briefing. The flu will be with us for a few more months.
H1N1, commonly known as swine flu, has spread to 208 countries and territories, according to WHO which declared an influenza pandemic last June. The virus has officially killed at least 12,220 people, but the true death toll is much higher and could take two years to establish, it says.
Chan said last week it would take another six to 12 months for the first pandemic in more than 40 years to run its course.
She called for continued vigilance, noting that pregnant women, young people and those with chronic medical conditions like asthma are at greatest risk.
Azerbaijan and Mongolia are scheduled later this week to become the first developing countries to receive donated H1N1 vaccine doses, Chaib said.
In all, six drug companies and 14 industrialised countries have pledged nearly 190 million doses for use in 95 developing countries, she said.
GlaxoSmithKline, Novartis and Sanofi-Aventis are among major producers of H1N1 vaccine.
(Reporting by Stephanie Nebehay; Editing by Jonathan Lynn)