Tests have shown giving children a polio jab which was last used in the 1960s can cut the chance of carrying the disease by up to 70 per cent.
Dr Jacob John, from the Christian Medical College in India, recruited 450 children from a densely populated village, all of whom had previously received the oral polio.
Half of them were then given a dose of the injected vaccine.
A month later all received a dose of the live oral vaccine to stimulate reinfection but tests showed the jab significantly reduced the chances of them carrying the two polio strains, serotypes 1 and 2.
Compared with children that did not receive the injection 38 per cent had fewer serotype 1 and 70 per cent had fewer serotype 2, The Lancet medical journal reported.
The polio virus has been found in sewage samples near Sao Paulo in Brazil, one of the host cities for the current World Cup football tournament, the World Health Organization said.
No human case of the disease has been reported in Brazil so far.
The polio virus found was found in sewage collected in March at Viracopos International Airport. It is a close match with a recent strain isolated in a case in Equatorial Guinea, the organisation said.
Several national football teams have arrived to Sao Paulo via the Viracopos airport.
The United Nations agency said that it assessed the risk of further international spread of polio virus from Brazil as "very low."
The recent spread of polio across Middle Eastern and African countries is an international public health emergency that threatens to infect other countries, the World Health Organisation (WHO) has warned.
The WHO said an co-ordinated international response was needed to stem the crippling disease, that tends to strike children under five and is usually spread via infected water.
Health experts are particularly concerned the virus continues to pop up in countries previously free of the disease, such as Syria, Somalia and Iraq, where civil war and unrest threatens efforts to contain the virus.
More polio cases have been confirmed in two new areas of Syria, including near Damascus and in northern Aleppo, near Turkey, according to the World Health Organisation. The incurable virus was confirmed this month in 13 children who became paralysed.