Most people understand that polio vaccines have helped to control and get us close to eradicating polio.
Many even know that there are two types of polio vaccine – the inactivated Salk vaccine and the live Sabin vaccine.
Some might even know that there are actually three strains of polio virus that we have traditionally gotten vaccinated against, and that one of those strains, type 2, has already been eradicated.
“In April 2016 a switch was implemented from trivalent OPV to bivalent OPV in routine immunization programmes.”
OPV Cessation
That’s why we have switched to using a bivalent OPV which only contains type 1 and 3 serotypes.
Contaminated Vaccines in India
What does all of this have to do with the news of contaminated vaccines in India?
“At least three batches of polio vaccines containing 1.5 lakh vials have been found contaminated with type 2 polio virus, putting at risk India’s “polio free” status as children born after April 2016 — when the type 2 virus was withdrawn worldwide including in India — do not have immunity to this particular virus, sources said.”
Unfortunately, some contaminated vaccines were actually administered to children in the Indian states of Maharashtra, Telengana, and Uttar Pradesh before the contamination was discovered.
Will these kids get polio?
No, as the vaccines weren’t contaminated with wild polio virus.
It seems that Bio-Med Private Limited was still producing and distributing polio vaccine with the type 2 vaccine virus, even though this type of vaccine was discontinued a few years ago.
Why?
We will hopefully find out, as the managing director of Bio-Med Pvt Ltd has been arrested, but we don’t know yet.
We do know that there is little risk from these vaccines and they won’t put India’s “polio free” status at risk.
Why would there be any risk from kids getting an extra vaccine virus strain?
It’s because the type 2 strain of polio is the most likely to cause cVDPV, or outbreaks of polio that are actually caused by the polio vaccine.
Fortunately, these outbreaks are very rare.

But kids in the area are at even less at risk from these “contaminated” vaccines because as part of the plan to switch from trivalent oral polio vaccine (tOPV) to bivalent oral polio vaccine (bOPV), they likely got a dose of IPV, which includes protection against all three polio virus strains.
Not that this means that it isn’t a problem that a company was making and distributing a vaccine that kids shouldn’t have been getting.
That is terrible!
It just isn’t as big a danger as some folks are making it out to be. It is extremely unlikely that there will be any cases of polio in India, and definitely not a resurgence of polio because of these vaccines, as some have suggested.
The real risk will be that an isolated event will scare folks away from getting vaccinated and protected, even though we know that these events are rare and that vaccines are safe.
More on Contaminated Vaccines in India
- Polio virus in Mumbai sewage sparks fear
- Ghaziabad pharma firm produces spurious polio vaccines, MD held
- Central Drugs Standard Control Organisation (CDSCO)
- WHO plays down risk to Indian children from tainted polio vaccine
- WHO – Replacing trivalent OPV with bivalent OPV
- The switch from trivalent to bivalent oral poliovirus vaccine: Will it lead to polio?
- One Month To Go until the Switch from Trivalent to Bivalent Oral Polio Vaccine
- OPV Cessation
How can this happen? Such a bad state of healthcare in India!