Subtitles section Play video Print subtitles ah, lot of stock is being placed in covert 19 vaccines, bringing about herd immunity. Some governments and officials hope they could suppress the pandemic altogether. But the concept comes with caveats on experts say such expectations are misplaced. Reuters health correspondent Kate Talent. So some scientists are worried that the concept of herd immunity is being misunderstood. Um, they worry that people wrongly believe that it would be something that they can rely on as individuals to protect them, even if they don't get vaccinated. Andi. They also think there is a misconception about what's involved in achieving herd immunity. Estimations of the threshold we need to reach for herd Immunity varies depending on who you ask. Most estimates say between 60 to 70% of the population needs toe have immunity of some form, either through vaccination or from previous infection. But all of that hinges on the elusive reproduction rate or our value, the measure of how much the virus is being transmitted on how much it is circulating. So the R value is really important when it comes to trying to figure out what percentage coverage we need to get herd immunity with vaccines. The problem is that we can't calculate the R value of this disease. That's partly because it's a new virus on partly because we are not living in normal times. Another unknown is whether vaccines will stop the transmission of the virus. So the data we've seen so far from the front runner vaccines from Fighter by on Tech on DFO from Madonna do suggest that they are very good at preventing disease. So there's a 90 to 95% efficacy rate in preventing disease. This doesn't, however, mean that they will stop transmission of the virus. So some say, aiming for herd immunity is fruitless. What some of the experts that I've spoken to are saying is that what we should be focusing in on is protecting the most vulnerable people, so vaccinating the most vulnerable people, the old on those with co mobility's.