- Most of the world’s people need to be inoculated to achieve ‘herd immunity’ to significantly slow or stop transmission, experts say
- ‘Worst case scenario is vaccine nationalism, where countries take a me first or me only attitude,’ health professor says
Tens of thousands of volunteers around the world are being injected with experimental Covid-19 vaccines as developers race to find effective prevention. A successful vaccine could be the escape hatch from a pandemic that in the space of half a year has cost hundreds of thousands of lives and trillions of dollars.
But the real test may depend on how many people have access to a vaccine. A majority of the world’s 7.8 billion people would likely need to be inoculated to reach the critical mass or “herd immunity” to significantly slow or stop transmission, experts say.Finding a successful vaccine, or several, is not guaranteed, though researchers are hopeful from early trial results. But it could take months or years to deliver billions of doses to all corners of the world. That is even as production capacities are being built before the vaccines are approved.
Hurdles include vaccine approval in individual countries, gearing up manufacturing sites, delivery logistics and organising vaccination campaigns.