Why will a vaccine not be the ultimate end to the pandemic? originally appeared on Quora: the place to gain and share knowledge, empowering people to learn from others and better understand the world.
A safe and effective vaccine may very well be the ultimate end of the pandemic, but it’s not a silver bullet because it will not be immediate, and because we don’t know yet what form it will take when (and IF!) it becomes available. Will it be 100% effective? 50%? Will it give lifelong immunity, or will we need booster shots every six months? We have enormous and probably unprecedented effort and resources in the global scientific community devoted to this, but we just don’t know yet what form this might take.
Even if a 100% effective vaccine that was perfectly safe were available today, it would take time to manufacture and distribute it to everyone in the world. This may sound simple, but it has taken many years to reach people all over the world with even routine childhood vaccination. Mass vaccination is an enormous undertaking.
Beyond the logistical challenges, for the first time in history we have an anti-vaccine movement for a vaccine that doesn’t even exist yet! We can’t underestimate the potential impact of vaccine hesitancy and vaccine refusal when it comes to our ability to rely on vaccination to end this pandemic. We would need around 80% coverage in all population groups across the world to achieve herd immunity, which is when enough people are immune to a disease and can’t pass it on, that people who aren’t immune are protected because the virus can’t find enough “hosts” to keep moving around in a community. Knowing the vaccine resistance and the logistical challenges we already face, it may take a long time to reach that, or we may never reach it. Just having an average of 80% isn’t enough – it has to be consistent across the population, otherwise you end up with pockets or specific geographic areas that haven’t reached that threshold, where the virus can still take hold and cause an outbreak.
We also need to be ready for a phased roll-out, where higher risk people and people who are more exposed to the virus get the vaccine first. This could include strategies where healthcare workers and others who face continual risk of exposure to the virus get the first round of vaccination, followed by the elderly and those with underlying conditions, before the general population gets access. This should be happening at a global level, not just at the national level, meaning that frontline workers everywhere need to be prioritized. No one is safe until everyone is safe, and having entire countries, or the poorest people in each country, or the hardest to reach, being entirely unvaccinated would mean we never see the end of this.