The country’s Health Ministry said that vaccines from Gardasil batch NH52670, nearly 80,000 of which have already been distributed, would no longer be administered following the adverse event report by health authorities in Valencia last week.
A health department spokeswoman for the region in Eastern Spain told AFP: "One of the girls got out of intensive care this weekend and the other is still there. Both are in stable condition."
While the country's regulators said that other Gardasil batches would continue to be used, the news is a further blow for Merck and European marketing partner Sanofi Aventis which have been battling for market dominance with the GlaxoSmithKline’s (GSK) rival product Cervarix.
In an analyst note, WestLB’s Simon Mather said that the news was mildly positive for Glaxo, though in any case, Glaxo's Cervarix shot had been chosen in 80 per cent of recent tenders.
Mather added that: “Although millions of doses have been administered worldwide without any side effects, it could strengthen Glaxo's claims for winning future tender bids with its rival cervical vaccine Cervarix if it transpires that batches or Gardasil are found to be contaminated."
Merck and Sanofi’s joint venture Sanofi Pasteur MSD, said it is working with health authorities to investigate the situation, but added that an adverse event after vaccination did not mean the vaccination had caused it.
The firm went on to say that: "In both cases, other medical conditions have been observed and are being investigated which could be the cause of the reported events."