It is depressing that we have a health secretary who does not understand, let alone believe in, herd immunity (Tory rebels fire warning shot as 42 MPs vote against stricter Covid measures, 13 October). The three examples that he quotes of diseases that never reach herd immunity are all incorrect, in different ways.
With malaria, the problem is the lack of individual immunity, and with flu the problem is that different strains of the virus emerge from time to time, bypassing any herd immunity that has built up. But it’s his inclusion of measles that really upsets me. You do get herd immunity, in the adult population, but this gets diluted out because people keep having babies. This can be easily counteracted by vaccination of children.
Because measles is far more infectious than Covid-19, with R possibly as high as 20, achieving herd immunity requires vaccine uptake of about 95%. Obtaining that requires a continuing campaign to counter the ignorance and misinformation about vaccines that is circulating.
By wrongly suggesting that herd immunity is impossible for measles, Matt Hancock has just shot himself, and us, in the foot.
Prof Jeremy Dale
Well, don’t that just shoot that fox?
Jeremy Dale studied medicine at Cambridge University and the Middlesex Hospital, London. Following GP vocational training in Oxford, he was appointed as a lecturer in primary care at King’s College School of Medicine and Dentistry in London, becoming a senior lecturer in 1992. While in London, he also worked as a part-time GP principal in a busy general practice in one of the most socially deprived parts of the city. In 1997, Jeremy was appointed Professor of Primary Care at Warwick. Between 1998 and 2007 he was the Director of the Centre of Primary Health Care Studies and between 2003 and 2006 was Head of the Division of Health in the Community at Warwick Medical School. He is also a part-time GP with the Engleton House Surgery in Coventry.