Britain Can’t Put All its COVID Eggs in the Vaccine Basket
Adam Hamdy sets out why the Boris Johnson administration is mistaken in its belief that a vaccine alone will allow life to return to normal
In February, a former Cabinet minister asked me to write a paper for the Health and Social Care Secretary Matt Hancock about the risks of Coronavirus reinfection and persistence – risks which could now jeopardise the Government’s vaccine gamble.
The four widely circulating endemic coronaviruses have a median reinfection interval of nine months and researchers who study these viruses don’t know whether such reinfections are caused by viral mutation or a decline in protective immunity.
We don’t know how long protective immunity to COVID-19 lasts or whether reinfection will be common. There are currently 26 confirmed cases and almost 1,000 well-evidenced cases of SARS-CoV-2 reinfection worldwide.
If the Government had recruited a Coronavirus virologist to its Scientific Advisory Group for Emergencies (SAGE), it might have known that the potential for the endemic coronaviruses to persist in the body in a low replication state has long been a concern among researchers, who suspect that such persistence might play a role in neurological disorders such as Parkinson’s disease.
A team from the Pasteur Institute has found the viral persistence of SARS-CoV-2 in the olfactory mucosa of four patients who were negative when given a PCR test. All four patients were experiencing prolonged loss of their sense of smell, but standard PCR tests showed them as having cleared the virus.
How many other people have unexplained long-term symptoms that reflect nothing more than an inability to detect low-level persistence of the virus in different sites around the body?
Another team from the Nussenzweig Lab at Rockefeller University found persistent SARS-CoV-2 virus in the presence of neutralising antibodies, in the small bowels of 50% of subjects, months after initial infection.
Such evidence of viral persistence might explain some of the ongoing symptoms suffered by those with Long COVID, an emerging condition that seems to affect at least 10% of those infected by the SARS-CoV-2 virus and which can encompass renal, cardiac, pulmonary, immune, endocrine and neurological disorders.
The Government’s 2011 UK Influenza Preparedness Strategy viewed vaccines as an endpoint and, put simply, the UK’s pandemic strategy was to hang on for a vaccine, which the plan said should take four to six months to deliver, at which point mass vaccination and economic recovery could begin.
Natural infection or vaccination typically confer almost lifelong immunity to an individual influenza strain, so that a pandemic strain can be extinguished. Vaccines are an endpoint for flu. The same is not necessarily true of coronaviruses.
Protection from Infection
The figures published by Moderna, Pfizer and others on the efficacy of the COVID-19 vaccines they have developed are very encouraging, but we have no idea how long protective immunity might last.
We also do not know whether vaccines will protect against all the variants now in circulation. Coronaviruses are relatively stable, but the high number of infections worldwide has led to a diversity of variants that increases the risk of immune escape – that one or more variants will be sufficiently different to be beyond the protective effects of a vaccine. This is particularly true of the variants that have emerged from infected mink. Allowing widespread transmission of the virus undermines vaccine efforts and puts them at risk of becoming ineffective.
As yet, we don’t have any data on whether the vaccines prevent infection. Vaccines that protect against severe illness will be a welcome addition to the fight against COVID-19 but, without sterilising immunity, they will not be the silver bullet that the Government is banking on.
If vaccines do not protect against infection, they may not be effective at slowing transmission. More worryingly, they might not provide any protection against viral persistence.
Many Long COVID sufferers only had mild illness during the acute phase of infection, and long-term symptoms do not appear to correlate with initial severity. If vaccines do not prevent Long COVID, they will not allow life to return to normal. Vaccines that protect against the worst effects of acute infection will be very welcome, but until we understand more about Long COVID and whether we are witnessing the emergence of a new chronic condition, other public health measures will be essential.
There are currently no plans to vaccinate children and, until there is a sterilising vaccine that can be given to them, they will continue to be a reservoir for infection. While it is true that children generally do not suffer badly from the acute effects of COVID-19, we have no idea of the disease’s potential long-term impacts on them. There are increasing reports of children suffering from Long COVID and it is essential to understand what causes the condition and what it might mean for their future health.
Countries such as Australia, New Zealand, South Korea, Vietnam, China, Taiwan, Singapore and others have demonstrated how to protect public health and their economies. They have done this with a ‘boots on the ground’ response to the disease, combining proven public health measures with innovative new technology.
By driving down cases, these countries have minimised loss of life, ill health and economic harm. Unlike the British Government, they aren’t betting everything on vaccines.
Adam Hamdy is an author and helped to organise and write the ‘John Snow Memo’