A/H1N1 influenza vaccines licensed by regulatory authorities were safe despite some adverse events following vaccination, the World Health Organization (WHO) said on Friday.
A WHO experts group has reviewed early results from the monitoring of people who have received A/H1N1 pandemic vaccines and found no indication of unusual adverse reactions, the UN agency said in a statement.
Some adverse events following vaccination had been notified, but these were well within the range of those seen with seasonal vaccines, which had an excellent safety profile, it said.
While early results were reassuring, monitoring for adverse events should continue, it added.
According to the agency, the Strategic Advisory Group of Experts (SAGE) on Immunization, which advises WHO on policies and strategies for vaccines and immunization, discussed the current situation of the A/H1N1 pandemic and issues on vaccination during an Oct. 27-29 meeting in Geneva.
The experts noted that a variety of pandemic vaccines, including live attenuated and both adjuvanted and non-adjuvanted inactivated vaccines, had now been licensed for use by regulatory authorities in different countries.
They recommended the use of a single dose of A/H1N1 flu vaccine in adults and adolescents, beginning at the age of 10 years, provided such use was consistent with indications from regulatory authorities.
According to the SAGE experts, data on immunogenicity in children older than six months and younger than 10 years are limited and more studies are needed.
SAGE further stressed the need for studies to determine dosage regimens effective in immunocompromised persons, those with weakened immune systems.
Concerning vaccines for pregnant women, SAGE noted that related studies had found no evidence of direct or indirect harmful effects on fertility, pregnancy, development of the embryo or fetus, birthing, or post-natal development.
SAGE recommended that any licensed vaccine could be used in pregnant women, provided no specific contraindication had been identified by the regulatory authority.
The A/H1N1 influenza has infected more than 410,000 people and caused some 5,000 deaths worldwide since it was first identified in North America in April, according to the WHO.
The agency has said that vaccination is "one of the best tools" for countries to deal with the pandemic, the first pandemic since 1968.