Islamabad, June 7 : Pakistan launched a campaign on Monday to vaccinate millions of children against polio, as new coronavirus cases decline in the country, officials said. The five-day campaign will target more than 30 million children under the age of five, reports dpa news agency. Around 223,000 frontline workers will spread out across 124 of the country's 154 districts to administer the oral drops, following Covid-19 safety protocols. According to official statistics, only one case of polio has been reported so far this year. "Back-to-back anti-polio drives during the Covid-19 lockdown that helped us reach maximum children in high-risk areas and improved security are behind decline in new cases," a Health Ministry official told dpa. Pakistan and Afghanistan are among only a few countries in the world where polio is still endemic. The country came very close to eliminating polio, but recorded 147 cases, a five-year high, in 2019, amid vaccine boycotts and attacks on health workers. Pakistan started a polio programme in 1994, but the work of the health workers was repeatedly hampered by violent incidents by extremists. The UN-funded drive to vaccinate children under the age of five also faces opposition from religious conservatives, who believe the vaccine, administered in multiple rounds, is intended to make Muslim children sterile. The polio vaccination drive started as the country witnesses a decline in daily new infections of coronavirus and educational institutions reopen. The ratio of coronavirus tests returning positive has dropped below 4 per cent this week from more than 10 per cent during most of April-May period. A total of 922,824 people have been infected in Pakistan with 21,323 deaths so far, according to the national statistics. /IANS