Most probably it was intranasal polio vaccine which was meant: https://www.sciencedirect.com/science/article/pii/S0264410X17304425 https://www.sciencedirect.co

Most probably it was intranasal polio vaccine which was meant: https://www.sciencedirect.com/science/article/pii/S0264410X17304425 https://www.sciencedirect.com/science/article/pii/S0264410X1...