Former Immunisation Director Warns the World won’t Return to Normal Even After Vaccine

“Much has been said about how the world will return to normal when a vaccine is widely available. But that really won’t be true.” David Salisbury, former director of immunisation at the Department of Health in London, has warned those pinning their hopes on a COVID-19 vaccine. Many people expect the pandemic to end as soon as a vaccine becomes available. But Dr. Salisbury warns that we need to be realistic about what vaccines can and can’t do. No vaccine is 100% effective. But in order to stop the spread of COVID-19, we must have a high level of immunity in our communities. That means we need a highly effective vaccine, and a large proportion of the population vaccinated. If we have a reasonably effective vaccine – say, 75% effective – and half the population get vaccinated, only 37% of people will be protected from COVID-19. Even if 75% of the population get vaccinated, only 56% of people would be protected – leaving close to half the population vulnerable to infection. Under these conditions, the coronavirus would still be able to spread through communities. To get rid of all our other COVID-19 measures under these circumstances puts many, many people at risk. Even if we do get a highly effective vaccine, there will be many challenges. Manufacturing and transporting the vaccine, vaccinating vulnerable groups, and convincing those less at risk to get vaccinated – these are all significant challenges we will need to overcome. Vaccines are one of the most powerful weapons we have against disease, but we need to be realistic about what they can achieve. To get rid of all our other COVID-19 measures (social distancing, mask wearing, hand hygiene etc) without a high level of protection in the population puts many, many people at risk. Australia, let’s be hopeful, but not unrealistic. Our progress with a COVID-19 vaccine is exciting, but we need to be prepared to keep up our hand washing, mask wearing, and social distancing for the foreseeable future.