The prospect of longer and warmer days in the Northern Hemisphere heralds the return of less favourable conditions for COVID-19 but instead we seem already to have entered a third wave of infections in Europe, with the threat of new mutations spreading elsewhere (including countries that have hitherto been coping well).

Meanwhile, poorer countries, both North and South, will remain largely exposed until next year at the earliest. The grim reality is that the virus is still far from beaten. Figure 1 shows there have been two waves so far and it is worth remembering that ‘Spanish Influenza’ had four.

Spirits are understandably high in the US, which is benefitting from a spectacular rollout of 100 million vaccinations so far. Other countries, making especially good progress include the UK, Israel, United Arab Emirates, Chile and a number of tax haven and holiday islands.

There seems little doubt that mass vaccination will save lives and reduce the number of sufferers from debilitating ‘long COVID’ while allowing economic activity to bounce back. Nevertheless, serious challenges remain, including:

• Many people are refusing to be vaccinated.
• It is not yet known for how long protection will last post-vaccination.
• Evidence of post-vaccination transmission suggests herd immunity cannot be easily achieved.
  The current production problems may well be fixed in the next few months, but the supply and distribution issues seem set to continue into 2022, if not beyond.
• Even if some countries achieve ‘peak’ vaccination levels, they will still be exposed to infections from those that have not done so, which are likely to be in the majority for some time ahead.COVID-19 is already demonstrating a significant capacity to mutate.

Even if vaccinations enable containment in a growing number of countries the experience of lifting restrictions following successful lockdowns points to a high risk remaining of sporadic outbreaks. This may result in the reintroduction of social distancing, mask wearing and restricted public gathering as a minimum as well as new lockdowns and their related economic dislocations.