Huge stock has been placed in the development of a vaccine for Covid-19, with the Prime Minister suggesting this week that the disease will not be properly defeated without one. The government has held out on the idea of a vaccine being available as early as September.
So how are things coming along in the real world? Ten days ago the first results from a human trial of a Covid-19 vaccine – developed by Chinese company CanSino Biologics were published in the Lancet. The researchers, from the Jiangsu Provincial Centre for Disease Control and Prevention in Nanjing, reported an immunological response in most of the 108 people given the vaccine. But they were not able to assess how effective it would be in preventing infection, as the level of antibodies required to prevent infection is not known. They also reported adverse reactions in 81 per cent of those taking part – mostly mild cases of muscle pain and fever – rising with the size of the dose received. Nine people, however, developed a severe fever.
Hildegund Ertl, from the Wistar Institute in Philadelphia, said the results were 'a little disappointing'. Especially worrying, she noted, was that the oldest participants in the study – those between 45 and 60 – were the least likely to develop neutralizing antibodies. As we know, the risk of dying or developing serious symptoms from Covid-19 rises sharply with age. There would be limited use for a vaccine which, say, didn’t work in the over-70s – although it could be of some use among healthcare workers.
The CanSino vaccine is only one of 120 vaccines under development, many on an unusually accelerated timetable. Others may be better. But it is a reminder that we cannot take a vaccine for granted – and we cannot rely on one as a strategy for getting out of a lockdown which is hugely-damaging economically and in other medical aspects.