The death toll from swine flu climbed to 15 in Turkey on Wednesday amid simmering controversy over the country's vaccination campaign following the prime minister's refusal to have an injection.

The latest victims of the A(H1N1) virus were a five-year-old boy, two women, aged 24 and 31, and a 55-year-old man, a health ministry statement said.

Fatalities have sharply increased this week after the first death was reported on October 24.

Hospitals began vaccinating medical workers on Monday, along with people planning to travel to Mecca for the hajj pilgrimage, amid widespread public concern over the safety of the swine flu vaccine.

Eager to dispel the misgivings, Health Minister Recep Akdag had an injection before the cameras on Tuesday.

But his gesture was soon overshadowed when Prime Minister Recep Tayyip Erdogan publicly chided the minister over his insistent calls on citizens to get vaccinated, saying that some experts doubted the safety of the drug.

He then told reporters he would not have an injection himself.

Erdogan's remarks dealt an "irreparable" blow to the health ministry's credibility, the Turkish Doctors' Union said in a statement Wednesday.

It slammed the government for "failing to be convincing even within itsef" and cast doubt on "how competent it will be in managing a nationwide pandemic."

The Union insisted that - the benefits of the vaccine are much greater than the damage its possible side effects may cause. -

Opponents of the vaccine say its safety, efficiency and side effects have not been sufficiently tested.

One of the most vocal critics -- former health minister and current opposition lawmaker Osman Durmus -- has said people will be effectively used as "guinea pigs" and slammed the government for spending an estimated 335 million dollars (227 million euros) for the vaccine in times of economic crisis.

Some experts have played down the panic, saying that usual seasonal flu claims around 7,000 victims each year in the country of 71 million, more than the 5,300 deaths that swine flu may cause under the worst-case scenario.

Turkey received the first batch of 500,000 doses of the vaccine last month.

It plans to buy a total of 43 million doses and vaccinate 28 million people.

The vaccination campaign will also include at-risk groups such as young children, pregnant women, and those who suffer from diabetes, heart conditions and immuno-deficiency diseases.

More than 5,700 people have died worldwide since the virus was first discovered in April, with most of the deaths -- 4,175 -- in the Americas region, according to the World Health Organization.