A leading association of clinicians accused an 'anti-vaccination movement' of breeding suspicion about the (A)H1N1 swine flu vaccine in Europe and declared public health and lives were at risk.
The European Society of Clinical Microbiology and Infectious Diseases (ESCMID) said it was worried by the slow rate of vaccination in some European countries.
"ESCMID joins others concerned about the lack of uptake due to both public skepticism and deliberate misinformation being raised by a growing anti-vaccination movement in a number of countries," the Swiss-based group said in a press release.
"It is feared a low uptake of the vaccine could greatly hamper efforts to control the pandemic and increase pressure on health systems across Europe."
World Health Organisation (WHO) figures cited by ESCMID said swine flu was now "widespread" in 10 countries, with the cases of respiratory illness requiring medical intervention increasing in 17 countries.
"Failure of the vaccine campaign across Europe would entail wider spread of the pandemic, an increased possibility of adverse complications and increased possibility of the virus mutating into a more aggressive and/or drug-resistant form," the society's past president, Giuseppe Cornaglia, said.
The association took aim at criticisms that the vaccine was unsafe and unneeded.
"These criticisms are scientifically unfounded," the group said.
The vaccine "has been made in exactly the same way as the seasonal flu vaccine, by the same manufacturers using the same materials, except for one piece, the specific virus particle," it said.
"The safety and immunogenicity of pandemic vaccines has been tested in [a] large, randomized trial, without which the European Medicines Agency (EMEA) would not have approved the vaccine."
More than 5,700 people have died worldwide since swine flu was first discovered in April, with most deaths in the Americas, according to the WHO.
EMEA on Friday said that five million Europeans had been vaccinated so far.
"To date, the side effects reported have mainly been mild symptoms such as fever, nausea, headache, allergic reactions and injection site reactions, confirming the expected safety profile of the three vaccines."
In France, only 20 percent of adults polled in a survey published on November 14 said they were willing to be vaccinated. Seventy-nine percent said they were against.
In Britain, one person in two is reluctant about being vaccinated, according to a report published last Wednesday in specialist journal Pulse.