The vaccine, which will be injected at 14 weeks will provide the best protection against polio
Immunisation: Bhutan introduced the injectable inactivated polio vaccine (IPV) in addition to the existing oral polio vaccine (OPV) into routine immunisation across the country on July 4.

A dose of IPV has been introduced into routine immunisation program at 14 weeks after birth to provide best protection against polio. The introduction of the new vaccine is part of the WHO’s “polio eradication and end game strategic plan” which deals with eradication of the disease not only by wild polio virus but also OPV. The plan also calls for withdrawal OPV globally given the risk associated with use of OPV.

In the first phase of the withdrawal of OPV, type 2 components of OPV will be removed and only components 1 and 3 of OPV will be given.

Department of public health’s director, Dr Pandup Tshering said all components of OPV would be withdrawn by 2019.

He said the introduction of the new vaccine will also help reduce risks associated with removal of type 2 component of OPV, such as the emergence of vaccine-derived poliovirus or the reintroduction of wild type 2 poliovirus. “So far we have been using OPV, but sometimes the vaccine also causes polio,” he said.

Although no cases of polio have been reported during the last three decades, he said the virus is prevalent in many countries and that it can enter the country by air.

Many countries have already introduced the new vaccine. IPV is considered safe, whether given alone or in combination with other vaccines.

Dr Pandup Tshering said the launching of the IPV in Bhutan ensures that Bhutan joins the global drive to eradicate polio from the world.

WHO certified Bhutan polio free on March 27 last year. However, the public heath director said Bhutan would continue to monitor polio cases through Acute Flaccid paralysis (AFP) surveillance until polio is globally eradicated.

Dr Pandup Tshering said no reports of vaccine associated paralytic poliomyelitis (VAPP) and vaccine derived polio (VDPV) has been reported in Bhutan to date.

“We have decided to give IPV at 14 weeks because it is proven that immunogenicity is higher after 14 weeks due to reduction in maternal antibodies which otherwise will interfere with immunogenicity,” he said. “Immunisation will also maximise the benefit in protecting children against type 2 polio virus after OPV cessation.”

The public health director said health staff involved in immunisation has been trained on the introduction of IPV and that the vaccine has been distributed to health centres across the country. Unlike, OPV, IPV is not a “live” vaccine and thus carries no risk of vaccine-associated polio paralysis.

Bhutan is one of the few countries that have already introduced the vaccine in South Asia. WHO, UNICEF and Global Alliance for Vaccines and Immunisations (GAVI) provided technical support to Bhutan and GAVI has committed to provide the vaccine from 2015 until 2018 without co-financing.

Poliomyelitis (Polio) is an acute human communicable disease caused by poliovirus serotypes 1, 2 or 3.

Dr Pandup Tshering said every World Health Organisation (WHO) member country should introduce the programme into their routine immunisation schedule.

In 1988, the World Health Assembly resolved to  eradicate  poliomyelitis globally and  the Global  Polio  Eradication  Initiative  (GPEI)  was  established. Bhutan started vaccination against polio with the launch of its Expanded Program on Immunisation (EPI) in 1979.

Since the inception of planned economic development in 1961, Bhutan was able to provide effective and equitable health services through the Primary Health Care approach (PHC). In Bhutan, the last case of polio was reported in 1986, two years before the initiation of Global Polio Eradication Initiative (GPEI).

Bhutan achieved Universal Child Immunisation (UCI) in 1991 and since then immunisation coverage for all vaccines has been maintained above 90 percent. Routine immunisation coverage for 3rd dose of OPV at 14 weeks, which is a measure of effective polio vaccination, has been consistently over 95 percent.

By  MB Subba