Sir, – Writing in support of the stance taken by tennis world number one Novak Djokovic, Pat Naughton states that the immunity the player has acquired from previous infection is "more robust and longer lasting than vaccine-acquired immunity" (Letters, January 8th). This is not actually the case, although it seems to be widely assumed despite the frequency with which recurrent infections are reported.
Experimentally, this is clearly a difficult question to address. The Centre for Disease Control in Atlanta has, rather remarkably, done so. Across a hospital network they examined the pattern of Covid-related hospital admissions comparing patients who had been fully vaccinated against it with those who had experienced a confirmed case of the disease, provided either event had occurred between 90 and 180 days earlier.
They found that vaccine-induced immunity was more protective than that generated by infection. The difference was large, with Covid-related hospitalization being over five times more common in the previously infected than in the vaccinated.
The “factoid” that natural immunity is better than that from vaccination is a dangerous one. Infection with human papilloma virus can reliably be prevented by a vaccine, while the infection is persistent and can ultimately lead to cervical cancer. Tetanus is common globally, often fatal and can even recur. But thanks to vaccination most doctors in Ireland will never even see a primary case. In tuberculosis it is often the recurrences of infection that are most severe.
If this reality could be better understood as a result of a tennis player’s views, it would more than justify the media attention this issue has drawn. – Yours, etc,
BRIAN O’BRIEN,
Kinsale,
Co Cork.