Zika: Vaccine trials for disease linked to 'shrunken heads' could start this year, officials say

Zika could spread 'explosively' according to the World Health Organisation

Daniele Ferreira holds her son Juan Pedro during a session to stimulate the development of his eyesight at the Altino Ventura rehabilitation center in Recife, Brazil (REUTERS/Ueslei Marcelino)

Clinical trials for a vaccine for the Zika virus, which has been linked to brain damage in unborn children, may start by the end of the year, according to US officials.

Health experts in the US have said there are two potential candidates for the testing the vaccine on.

However, opinions on when the vaccine would be ready are conflicting. US officials said that the vaccine would not be ready for several years. But Canadian scientist Gary Kobinger, a lead developer for the vaccine, told Reuters that the first stage of human testing could start in early August – meaning it could be ready by autumn 2016.

Dr Anthony Fauci, director of the National Institute for Allergy and Infectious Disease, said that one option is to base the vaccine on previous research into the West Nile virus, which was not previously developed because of a failure to find a drug company partner.

However, he said that this would not pose an issue for Zika and that officials have already spoken to “a few companies” able to help advance the development.

Dr Kobinger, who helped to develop a trial vaccine to fight Ebola, said: "The first thing is to be ready for the worst.

"This vaccine is easy to produce. It could be cranked to very high levels in a really short time."

However, he did not say when it would be available widely.

The race to develop a vaccine comes after the World Health Organisation said it is spreading “explosively” and warned that the mosquito-borne virus could infect up to four million people in the Americas.

While it manifests itself as a relatively harmless fever in most cases, it is most feared due to its links to microcephaly – where babies are born with heads which appear to be shrunken due to brain damage.

Since October 2015, it has been linked to severe birth defects in thousands of babies in Brazil.

Additional reporting by Reuters