India launched a large-scale polio immunization programme in 1995 cooperating with international institutions, state governments, and NGOs to eradicate polio by vaccinating all children under 5 years old. While vaccination began in 1978 and expanded in the 1980s and 1990s, India saw its last case of wild poliovirus in West Bengal in 2011 and was declared polio-free by the WHO in 2012. The government implemented pulse polio immunization days along with surveillance and rapid response teams to achieve this goal with the help of millions of vaccinators and volunteers.