International experts have dispelled fears of purported hazardous impact of anti-H1N1 vaccines on pregnant women.
Director, Initiative for Vaccine Research, WHO, Dr Marie-Paule Kieny, said on Friday recommendations of the SAGE (Strategic Advisory Group of Experts on immunization) concerning pandemic (H1N1) vaccines have come to the conclusion that the priority groups are appropriate for vaccination, and that one doze of vaccine is suitable from 6 months age and upwards, that the safety profile was good and that pregnant women could be vaccinated by licensed vaccine by any national authority. Concerning vaccines for pregnant women, SAGE noted that studies in experimental animals using live attenuated vaccines and non-adjuvanted or adjuvanted inactivated vaccines found no evidence of direct or indirect harmful effects on fertility, pregnancy, development of the embryo or fetus, birthing, or post-natal development.
Based on these data and the substantially elevated risk for a severe outcome in pregnant women infected with the pandemic virus, SAGE recommended that any licensed vaccine can be used in pregnant women, provided no specific contraindication has been identified by the regulatory authority.
The experts reviewed early results from the monitoring of people who have received pandemic vaccines and found no indication of unusual adverse reactions. Some adverse events following vaccination have been notified, but these are well within the range of those seen with seasonal vaccines, which have an excellent safety profile. Although early results are reassuring, monitoring for adverse events should continue.
She added that for cases of less than 6 months of age there is no need for the vaccination of infants.
The experts noted that a variety of pandemic vaccines, including live attenuated and both adjuvanted and non-adjuvanted inactivated vaccines, have now been licensed for use by regulatory authorities.
SAGE recommended the use of a single dose of vaccine in adults and adolescents, beginning at the age of 10 years, provided such use is consistent with indications from regulatory authorities.
Data on immunogenicity in children older than 6 months and younger than 10 years are limited and more studies are needed.
Where national authorities have made children a priority for early vaccination, SAGE recommended that priority be given to the administration of one dose of vaccine to as many children as possible.
SAGE further stressed the need for studies to determine dosage regimens effective in "mmunocompromised" persons.
Dr Marie-Paule Kieny said concerning the seasonal vaccine, SAGE has recommend that it is safe that the two vaccines could be co-administered simultaneously, but not for the vaccines through the nose. Clinical trials investigating the co-administration of seasonal and pandemic vaccines are ongoing, but SAGE acknowledged the recommendation, from the US Centers for Disease Control and Prevention, that live attenuated seasonal and live attenuated pandemic vaccines should not be co-administered.
The experts recommended that seasonal and pandemic vaccines can be administered simultaneously, provided both vaccines are inactivated, or one is inactivated and the other is live attenuated.
The experts found no evidence that co-administration of vaccines, as recommended, would increase the risk of adverse events. The SAGE, which advises WHO on policies and strategies for vaccines and immunization, devoted a session of its 27-29 October meeting to pandemic influenza vaccines. SAGE also considered vaccines for use in the southern hemisphere during the 2010 winter season. Two options were assessed: a trivalent vaccine, effective against the H1N1 pandemic virus, the seasonal H3N2 virus, and influenza B viruses, and a bivalent seasonal vaccine, effective against H3N2 and influenza B viruses, which might need to be supplemented with a separate monovalent H1N1 pandemic vaccine.
The experts concluded that both options should remain available for vaccine formulations in the southern hemisphere, subject to national needs.
Dr Marie-Paule Kieny said that 156 million dozes of vaccine have been secured for the health organization and WHO is working to reach 200 million dozes that would be able to cover 10 percent of the population for 95 developing countries. The developing countries, she said, will receive dozes covering two percent of their population by the end of November.

- Kuna