Tuesday November 12, 2019

India introduces injectable Inactivated Polio Vaccine

0
//

By Nithin Sridhar

Health Minister JP Nadda launched India’s first injectable inactivated polio vaccine (IPV) on Monday. This marks the beginning of the shift from purely orally administered polio-vaccines or Oral Polio Vaccines (OPV) to a combination of dosages of OPV’s and IPV’s.

This is indeed a welcome move in the global fight against polio eradication.

One of the major disadvantages of OPV usage is that there is a chance that it leads to vaccine-associated paralytic poliomyelitis (VAPP). Studies have shown that one child out of every 2.4 million dosages of OPVs administered will suffer from VAPP.

This disadvantage can be overcome by the administration of IPV dosages. IPV was developed by Dr. Jonas Salk in 1955. IPVs consist of killed poliovirus strains (as against live attenuated polioviruses in OPVs) of all three poliovirus types which are then used as vaccines. Hence, they produce antibodies in the blood that provide immunity against all three poliovirus types resulting in protection against VAPPS as well. Further, IPVs are considered very safe and efficient and there are no major side-effects.

This is not to say that, IPVs have no disadvantage. For a long time, polio eradication programs were using OPVs alone because IPVs were observed to be weak in providing intestinal immunity. Hence, if a person immunized with IPV becomes infected with wild poliovirus, then the virus can still multiply inside the intestine and come out in the feces resulting in its continued circulation. But, a recent study shows that, when IPV is used in combination with OPV dosages, then IPVs will boost intestinal immunity.

Thus, World Health Organization (WHO) no longer recommends OPV alone vaccination against polio. It recommends usage of at least one dose of IPV in countries which is using OPV only vaccinations. In polio endemic countries, it recommends usage of 1 OPV birth dosage, 3 OPV dosages and 1 IPV dosage. In countries with high immunization cover and low chances of importation of wild polio viruses, but with a significant VAPP concern, WHO recommends an IPV–OPV sequential schedule. It recommends IPV only vaccination only in those countries which have low importation as well as transmission risks along with very high immunization coverage.

Hence, India’s move in introducing IPVs is in sync with WHO recommendations. This step will go a long way in preventing VAPP and ensuring complete polio eradication from the world.

(Photo: www.erewise.com)

Next Story

World Health Organization Says First Local Case of Polio Found in Zambia Since 1995

The U.N. health agency said there is no established link between the Zambia case and the ongoing Congo outbreak

0
World, Health, Polio
FILE - A Congolese child is given a polio vaccination at a relief camp near Gisenyi, Rwanda, Jan. 25 , 2002. The WHO says Zambia has reported its first local case of polio since 1995 in a 2-year-old boy paralysed by a virus derived from the vaccine. VOA

The World Health Organization says Zambia has reported its first local case of polio since 1995, in a 2-year-old boy paralyzed by a virus derived from the vaccine.

In a report this week, WHO said the case was detected on the border with Congo, which has reported 37 cases of polio traced to the vaccine this year. The U.N. health agency said there is no established link between the Zambia case and the ongoing Congo outbreak but said increased surveillance and vaccination efforts are needed, warning that “there is a potential for international spread.”

In rare cases, the live virus in oral polio vaccine can mutate into a form capable of sparking new outbreaks.

Nine African countries are currently battling polio epidemics linked to the vaccine as WHO and partners struggle to keep their efforts to eradicate polio on track. Elsewhere, cases have been reported in China, Myanmar and the Philippines.

World, Health, Polio
In a report this week, WHO said the case was detected on the border with Congo, which has reported 37 cases of polio traced to the vaccine this year. Pixabay

On Thursday, WHO and partners are expected to announce they have rid the world of type 3 polio virus.

There are three types of polio viruses. Type 2 was eliminated years ago. That now leaves only type 1. But that refers only to polio viruses in the wild. Type 2 viruses continue to cause problems since they are still contained in the oral polio vaccine and occasionally evolve into new strains responsible for some vaccine-derived outbreaks.

The global effort to eradicate polio was launched in 1988 and originally aimed to wipe out the potentially fatal disease by 2000. While cases have dropped dramatically, the virus remains stubbornly entrenched in parts of Pakistan and neighboring Afghanistan. This year there have been 72 cases of polio in Pakistan after only eight in 2018.

Also Read- US Endorses Smokeless Tobacco as Less Harmful than Cigarettes

In meeting notes from an expert polio oversight board in September, WHO’s Michel Zaffran said the status of eradication was “of great concern,” noting the Taliban’s ban on house-to-house vaccination in Afghanistan. Officials described the program in Pakistan as a “failing trajectory.” (VOA)