Despite the fact that vaccination has helped avert many deadly infections and save lives, controversies and attitudes continue to bog down efforts to eliminate diseases by vaccine use REUTERS

The recent outbreak of measles in the US with 102 cases reported in January has been linked to a single outbreak at Disneyland in California, caused by a lack of vaccination among some children, whose parents believe that the vaccine is dangerous and that measles is not.

The number of cases in a month are more than that during an entire typical year, according to the Centers for Disease Control and Prevention's National Center for Immunization and Respiratory Diseases.

At 644, the number of measles cases in 2014 was the highest since 2000 when it was considered eliminated in the US.

Combined with a low vaccine uptake for many other diseases, this case points to a growing disbelief in vaccines.

The anti-vaccination drive followed a British study alleging a link between autism and childhood vaccines. The study was later debunked and Lancet fully retracted the original publication, but public opinion did not change much.

Recently an Arizona cardiologist, Dr Jack Wolfson, who has become a face of the anti-vaccination movement in the US after refusing to vaccinate his children told CNN, "It's not my responsibility to inject my child with chemicals."

A survey from the Pew Research Center showed that 68 percent of US adults believed that vaccinations of children should be required, while 30 percent say that parents should be able to decide not to vaccinate their kids.

Recent outbreaks of measles, Haemophilus influenza type B invasive disease and pertussis, have all been attributed to vaccine refusal resulting in under-immunised infants and children.

Declining deaths

Before the introduction of a live measles vaccine in 1963, the average yearly number of measles cases in the US was 549,000 with around 500 deaths per year.

A resurgence of the disease with 123 deaths later led to a two-dose vaccine regimen.

Measles, while not always fatal, is potentially serious and a highly communicable respiratory disease caused by a virus and spread through the air.

It starts with a fever, runny nose, cough, red eyes and sore throat. Pneumonia (a serious lung infection), lifelong brain damage, deafness and death in some cases are reasons why the MMR shot is recommended.

The earliest version of the MMR vaccine, developed by John Franklin Enders in 1958 was a live virus vaccine and came with the side effect of introducing the disease. But since then, the vaccine has been attenuated to cause the slightest of symptoms by way of a fever, and not the disease.

Vaccines work by triggering antibodies within the body without actually causing the disease. Usually made from the disease causing pathogen, vaccines are attenuated or modified versions that prod the immune system into recognising the pathogen and responding to it.

Since the days in the 19th century when Edward Jenner first used material from cowpox pustules to provide protection against smallpox, and Louis Pasteur made the rabies vaccine, vaccines against diphtheria, cholera, anthrax, typhoid, polio and tuberculosis have contributed in a big way to offset the devastating effects of deadly diseases.

In fact, experts believe that vaccines have saved more lives than all the miracle drugs of the 20th century, including antibiotics and antivirals.

Resistance to vaccines

Among the more recent vaccines developed are those against the human papillomavirus (HPV) which is the most common sexually transmitted disease and widely associated with cervical cancer.

However, concerns of safety as well and parental attitudes have contributed to the relatively low HPV vaccine uptake of both brands, Gardasil and Cervarix, both proven in clinical trials to be 99% safe and effective.

With the control and elimination of deadly diseases, fear of disease has shifted to concerns on vaccine safety, believe experts.

It has not helped as pharma companies conceal trial data often and as many as half of all clinical trials are never published, PLOS Medicine said in 2013.

In India, opposition has been growing against the newly introduced Pentavalent Vaccine (DPT+ Hib + Hep B vaccine) which is proposed to be rolled out nationwide this year.

Pentavalent vaccine

Almost 128 children have succumbed to adverse events following immunisation with experts from the Indian Academy of Paediatrics (IAP) saying the data is the tip of the iceberg as most of the deaths go unreported.

According to IAP, most of these deaths are caused by pentavalent vaccine.

Pentavalent vaccine is a five-in-one conjugate that combines antigens against five infections - diphtheria, pertussis and tetanus (DPT), hepatitis B and Hib Meningitis.

The frequent deaths in healthy children from vaccines has seen the immunisation uptake fall by 25 percent in the last four years in the state of Tamil Nadu alone.

A study on Hepatitis B vaccine (included in the Pentavalent vaccine) published in the journal of the Indian Academy of Pediatrics showed the vaccine does not protect babies from infection.

When asked about the deaths, deputy commissioner of the National Immunisation Programme at the ministry, Dr Pradeep Haldar belittled the deaths, saying, "Twelve more states are on our list and PV will be included in routine immunisation soon. We have also created a team to investigate adverse effects following immunisation (AEFI). We will soon have results — till then, we will not stop. So far, 20 lakh doses have been consumed in the country, with 76 deaths of those vaccinated. It is better to be vaccinated than to die of an infection."

It is a well known fact that the Oral Polio Vaccine caused epidemics of paralysis in Nigeria and India during the last decade.

In India, problems relate largely to vaccine quality, contamination in storage in manufacturing, and complications from the health of the child.

However, there are also growing sections of experts and society who are inclined to think that the vaccine is more dangerous than the disease.

Public misinformed?

Sometimes it is the fear of introducing a live virus, at time a religious objection as seen in the US against vaccine viruses grown in cell lines from aborted fetal tissues; and often concerns regarding too many vaccines overloading or weakening the infant immune system.

The number of recommended childhood vaccines has increased exponentially in the last 50 years. In the US, a fully immunised child by the age of two years will have received 14 different vaccines and up to 26 injections.

Today's vaccines contain far fewer antigens than the immune system is designed to respond to, say medical practitioners. Parents and caregivers should be reassured based on these data that vaccines will not overwhelm or weaken the infant immune system.

The prevailing situation both in the developed and developing worlds raise concerns over how a lack of transparent and authentic information can compromise public health and see a rise in preventable diseases.