"I did not want to make a mistake," Mehmet, 36, a father-of-two, told Anadolu Agency (AA) about his decision to shun what he calls Turkey's "mandatory vaccination program."

The former English teacher who now runs a publishing house does not want to reveal his identity, fearing the authorities or doctors will pursue him and his family, forcing them to get vaccinated.

"I did not vaccinate my two daughters [aged six and three]. We learned that during the first two years of a newborn's life, she develops her immune system; a direct interference from outside would prevent her developing the system properly and naturally."

"We came to the conclusion that if we want our children to be healthy, we have to stay away from this vaccination program," he claimed.

Mehmet is not alone. One local doctor speaking to AA on condition of anonymity described a "silent mass" against vaccination.

And this "silent mass" is getting organized.

Bahadır Cevizci, a prominent member of Turkey's Movement Against Mandatory Vaccination, said the group has "helped" more than 150 families fight against immunization programs in court over the last three years.

Applications have grown in recent months, Cevizci said.

The group has a strong foothold on social media. At least 3,000 people have ‘liked' their Facebook page and there are also other similar Facebook advocacy pages.

Cevizci claims vaccination programs are not compulsory in the first place.

"There is no law saying that vaccination is mandatory," he said, claiming that Parliament can only enact such compulsory inoculation programs in the event of an epidemic.

Hakan Hakeri, a professor of medical law at Medeniyet University in Istanbul, admitted there is no law requiring parents to vaccinate their newborns.

"The Turkish Constitution says you have to get consent from families for medical care, but adds that certain laws would constitute exceptions.

"Turkey enacted a law in 1930 necessitating smallpox and tuberculosis vaccinations. The rest are not compulsory," Hakeri acknowledged, adding that the Health Ministry maintains the current immunization program on the grounds of public safety.

The ministry says immunization through vaccination is "the best medical care in society to prevent disease and deaths".

In a statement to AA, it maintained that vaccination has social and personal benefits, adding that the program eradicated epidemics like smallpox, saving many lives.

"Due to its success, many are aware of the devastating effects of measles, polio and whooping cough," the ministry added.

The government requires that a newborn be given 16 different vaccinations in its first 24 months.

However, anti-vaccination parents have been especially vocal against diphtheria, tetanus and whooping cough vaccinations - called DtaB in Turkey - as they believe they induce side effects such as autism.

Local health centers track vaccination progress and alert parents when their child's vaccinations are due.

Parents have the choice to refuse vaccinating. "If they do not want to do it, they are required to sign a paper showing that they take responsibility for their actions," a local doctor told AA.

The Family and Social Policies Ministry reviews the documents and can launch an investigation if it determines there is any negligence.

The Health Ministry has confirmed that it informs the Family and Social Policies Ministry whenever parents refuse to vaccinate their children, adding that the latter department can launch a court case against the parents concerned.

Turkey's anti-vaccination movement offers legal guidance in court cases to such families, Cevizci said. "We won most cases, but some are appealed."

If a family loses a case, doctors appear before the family's home with police to vaccinate the child. To avoid this, some families change their address to make it difficult for authorities to locate them, according to a local doctor.

However, a recent ruling was seen by some as a blow to their cause when the Supreme Court ruled in favor of the present immunization program.

On June 22, the court ruled that if families do not have valid grounds to refuse vaccination, the state has a right to enforce immunization.

Hakeri argued that this decision aims to prevent negligence.

"The court previously ruled that the ministry could not force vaccination and needs to listen to parents first. The recent ruling means that parents have to show a reason for their refusal. If they present a reason, that should be ok," Hakeri said.

Some experts do not share Hakeri's view. Lawyer Sunay Akyıldız said the court's ruling means general approval for the immunization program.

Recent developments in the U.S. have hit the global movement against compulsory immunization hard.

California introduced mandatory immunizations last month. The state requires children enrolling in schools to be immunized against diseases.

Other than California, only two other U.S. states - Mississippi and West Virginia - have such strict requirements.

Anti-vaccination families face trouble within society as well. "There has been social and family pressure as well on families to vaccinate their kids," the doctor said.

Parents who vaccinate their children know that unvaccinated children can potentially cause epidemics of diseases such as tuberculosis, putting everyone at risk.

A revival of smallpox in Africa after the celebrations over its ostensible eradication has rung alarm bells for some.

In 1979, the World Health Organization declared the eradication of smallpox, a highly infectious disease that was thought to have caused at least 300 million deaths during the 20th century alone.

Following the elimination of a vaccination program, a relatively unknown illness - human monkeypox (MPX) - has begun to spread in parts of Africa, according to University of California Los Angeles (UCLA) research.

Anne Rimoin, an associate professor at UCLA, wrote in a 2010 report that after the elimination of immunization in the Democratic Republic of the Congo, there was a 20-fold increase in human monkeypox.

Parents who do not vaccinate their children counter-argue with their belief that since so many children have been vaccinated, a few unvaccinated youngsters should not be a problem for society.

These parents also have some expert opinions supporting their case.

Professor Ahmet Rasim Küçükusta, an expert in chest illnesses, claims that vaccinations during the first 24 months could "be harmful due to its content."

"The number of vaccinations is too much. I don't approve of so many vaccinations," Küçükusta told AA.

Cevizci believes that there is an alternative way to improve children's immune systems and to protect newborns from dangerous germs.

"It is important to stay away from ready-made foods and chemical pills to develop a [strong] immune system," Cevizci said, implying the benefits of a more natural lifestyle and remedies.

Mehmet, the teacher-turned-publisher, seems to have been successful in his approach so far.

"My child experienced no serious illness during six years. She had a fever for 10 days. That's all," he said, highlighting his apparent success in taking care of his children.

Confusion and debate over the merits of immunization programs will not be settled anytime soon. The resistance among anti-vaccination families is high and they will not line up before a local health center for unwanted shots.

"We could be few in number. If the state does not act in favor of my beliefs, that's fine. But do not declare war on me," Mehmet said.