NEW DELHI (AP) — Doctors Without Borders has challenged Pfizer's application for an Indian patent for its pneumonia vaccine so cheaper versions can be available to children in poor countries and to humanitarian organizations.

The medical aid group, also known as Medicins Sans Frontieres, said in a statement late Friday that it was challenging Pfizer's patent application to allow Indian manufacturers to make affordable versions of the pneumococcal conjugate vaccine.

If Pfizer is granted a patent for the vaccine, Indian drug companies would not be able to make cheaper generic versions.

"The pneumonia vaccine is the world's best-selling vaccine, and last year alone, Pfizer brought in more than $6 billion in sales just for this product," Dr. Manica Balasegaram, Executive Director of MSF's Access Campaign, said in the statement. "Meanwhile, many developing countries, where millions of children risk getting pneumonia, simply can't afford it."

"To make sure children everywhere can be protected from deadly pneumonia, other companies need to enter the market to supply this vaccine for a much lower price than what Pfizer charges," Balasegaram said.

Doctors Without Borders said its decision to oppose New-York based Pfizer's patent application comes after "years of fruitless negotiations" to get the company to reduce the price of the drug for use in humanitarian projects.

Pfizer India said Saturday that the company had not yet received a copy of the patent opposition, and that it was in talks with Indian health officials to try to assess local needs.

Pneumonia kills almost a million children each year.

"As doctors who have watched far too many children die of pneumonia, we're not going to back down until we know that all countries can afford this vaccine," Balasegaram said.

To Learn More:

Supreme Court Rules in Favour of Generic Drugs, Rejects Bayer’s Appeal (by Karan Singh, AllGov India)

Indian Patent Ruling against Bayer Clears Way for Low-Cost Generics in Blow to Big Drug Firms (by Noel Brinkerhoff, AllGov)