Researchers at a London University have disclosed that swine flu vaccines administered to kids during last year's endemic, generally have small side-effects and should offer "good protection" against virus. The huge majority exhibited a "good response" in generating antibodies essential to combating the contagion in an experiment of over 900 kids carried out during the 2009/10 H1N1 endemic.

Around 98% of kids below three years of age reacted well to two doses of an "adjuvanted" vaccine that includes a mixture to increase immunity. This vaccine also dubbed as a "split-virus" vaccine, since the virus it is based on is split, was most frequently given to children last year.

Two dosages of a second "whole-virus" adaptation of the vaccine, without the jab, generated a less vigorous result, with 80% of below-threes acting in response. In kids over three, the variation between the two kinds of vaccines was less prominent, with 99% reacting to the adjuvanted vaccine and 95% to the vaccine devoid of adjuvant.

Whilst the adjuvanted vaccine was also the most liable to create side effects like fever, majority of the children influenced faced only slight reactions.

The study, printed in the British Medical Journal, was a partnership between the Health Protection Agency and the universities of St. George's in London, Bristol, Exeter, Oxford and Southampton reviewing both vaccines for protection, likelihood to cause reactions and capability to provoke an antibody reaction.