The big question:What

Vaccination has been heralded as our major weapon to beat COVID, but initial hopes that we could control SARS-CoV-2 infection through a robust and durable immunity derived through vaccination and/or prior infection have been challenged by the Omicron variant. Our turbulent learning curve has shown us that we can reduce disease severity and hospitalisations, but have been less successful at reducing community transmission.

Short-term vaccine goals should include ensuring vaccine equity, as we cannot control a global disease threat with only wealthy nations having access to vaccines; and we need to follow the logical developmental progression from monovalent to multivalent vaccine. Longer-term goals need to protect from serious disease and tackle community transmission. Vaccine redesign to stimulate a robust mucosal protective immunity could off er further benefi ts and might open up diff erent vaccine delivery options. Furthermore, we need to work on scientifi c communication to combat the wave of misinformation resulting in vaccine hesitancy. Future reduced engagement with vaccination eff orts could be a ticking time bomb for the future, such as that seen with measles infections through hesitancy with MMR vaccinations.

Living with COVID will most likely be paralleled by living with fl u – regular vaccination of vulnerable individuals, but certainly not ignoring COVID. We will hopefully reach a balance between health, societal and economic needs.

The approval of the fi rst COVID-19 vaccine for emergency use within a year of the initial reports of the disease is a massive achievement and our current vaccines are highly eff ective at protecting us from severe disease, hospitalisation and death. However, they are far from perfect. Boosters help maintain protection from serious symptoms, but we face a rapidly evolving foe and we need to update our vaccines to keep up with new variants, such as Omicron, that can evade some of the immune responses triggered by current vaccines. We need to modify our vaccines to include other viral proteins, that will also help broaden our protection against new variants. We hope to develop “pan-coronavirus” vaccines, utilising common antigens, with the aim of protecting us from all new variants. Current vaccines do not protect us against re-infection, nor do they prevent transmission to others, meaning that the virus can continue to spread and evolve. More eff ective control of viral replication in the airways, and subsequent transmission to others, may be achievable by delivering vaccines directly to the respiratory tract and the triggering of local immunity. Such a vaccine would also be easier to administer, as would oral vaccines that are also in development, and would assist delivering these desperately needed vaccines to the world. Vaccines have proved to be very eff ective. Let’s see if we can make them even better.

The vaccines that we have against the SARS-CoV-2 virus are a miracle of modern science. I was as surprised and delighted as anyone that it turned out to be possible to produce safe and eff ective vaccines within 12 months.

In the current pandemic phase, the vaccines are needed to serve two functions. The fi rst is protecting individuals from serious disease and death. All the vaccines that we have in use across the world at the moment are very good at this. The second is to help reduce the transmission of the virus. This can only be achieved in conjunction with other measures to stop the virus being passed between people. The virus will not be under control until every country in the world has vaccination rates of 85–90%.

All the vaccines currently available are of the type that stimulate an immune response, which only gives short-lived cover. It is also known that natural infection with coronaviruses does not lead to a lasting lifelong immunity. Both these factors suggest that, once the pandemic is under control, regular vaccinations might be a feature of our lives. It is to be hoped that the virus will settle down and stop the regular drastic mutations – though it is very unclear how long that might take. It is technically possible to change the formulation of the vaccines so that they target prevailing variants. So, in the long term, we might see an annual vaccine designed to provide cover against several variants of SARS-CoV-2 in one dose.