Study suggests Covid antibodies fade over time. How concerned should we be?

To answer this question, we need first to consider what antibodies are and what they can tell us about immunity

Newly released research suggests that levels of antibodies against the coronavirus have declined across the UK population since testing began. Having randomly sampled 365,000 people across the country, the React2 study – which is yet to be peer reviewed – estimates that 6% of the UK population had antibodies against the virus in late June, but that this had fallen to 4.4% by September.

If antibodies fade over time, how worried should we be? Does this mean we cannot be immune to COVID-19? To answer this question, we need first to consider what antibodies are