The great vaccine paradox

People have deep and irrational suspicion of vaccines. This mistrust has actually been studied and it registers in the top ten chart of World Health Organization (WHO) threats to global health.

The successful MMR vaccine for example, became a focus of concern when a piece of research, since totally discredited, linked MMR to autism. After it was published, the number of child immunisations declined and a spike in the number of deaths both in Europe and globally was detected.

There is no proof that the spike was directly linked to bad publicity and its likely many factors were in play. However, with a staggering 142,000, mostly children under five dying, from measles in 2018, the WHO felt obliged to publish a review, spelling out that three vaccines MMR, MMRV and MMR+V seem to have no links with autism.

Figure: In May 2018, 8,207 cases of measles were reported across Europe, taking that year’s total to 41,000.  Source: WHO

Few medical breakthroughs have had greater impact on human health than vaccines. They are the indisputable game changers in an unending war against contagions - so apparent today with the COVID-19 pandemic. Viruses can ravage populations, reduce life expectancy and create economic mayhem.

Every year according to the WHO, vaccines prevent more than three million childhood deaths from attacks by diphtheria, tetanus, pertussis and measles worldwide. Vaccines, such as those for HPV and Hepatitis B, also have extended those preventative benefits for young and mature adults. A new generation of vaccines, capable of harnessing a body’s immune system to treat disease rather than prevent it, is on the horizon and gene editing techniques such as CRISPR offer more opportunity.

But the search for a ‘magic bullet vaccine’ to immunise against the current strain of coronavirus, COVID-19, is going to test the skills and imaginations of bio scientists and clinicians to the limit. Time is not on their side and sometimes our own ignorance trips us up. Statements from leaders about disinfectant and bleach cures do not help, but anti-vaccine sentiment is more dangerous.

Horrible histories

Vaccines have regularly attracted their fair share of opprobrium. Go back in time to a visionary Dorset farmer; Benjamin Jesty, who in 1796 stimulated immunity to small pox by injecting cow pox into a milkmaid. Jesty predated Edward Jenner with his work. Jenner is credited with the more formal and rigorous scientific description of vaccination against deadly small-pox. But good farmer Jesty (photo) was reviled by locals for injecting animal pus into human beings. He was even pelted when he attended markets in his neighbourhood despite evidence that it was working.

He carried on his work when he moved around 1806 to Worth Matravers, near Swanage. There it's believed he inspired a local vicar Andrew Bell, to start inoculating 200 villagers. It says much that the Jesty, reviled by locals, today has a gravestone in the local churchyard which is a registered national monument.

Contemporary controversy

Step forward two centuries and the negativity about a successful vaccine resurfaced in the guise of a piece of academic work. The Wakefield report in 1998 appeared to link MMR vaccine with autism. It caused an ‘earthquake’ among the health care community and its after-shocks are still being felt.

Andrew Wakefield’s 1998 work was a case study around 12 children. It reported a ‘proposed new syndrome’ of enterocolitis and regressive autism and it was associated this with MMR as an ‘apparent precipitating event’. It got massive coverage in the popular press and soon a campaign against the MMR vaccine began.

In fact, three of nine children reported with regressive autism did not receive an autism diagnosis. Only one child clearly had regressive autism and five children had documented preexisting developmental concerns. Yet, the study reported all 12 children were ‘previously normal’.

The publicity generated by Wakefield had an effect on immunisation rates in Britain. They reportedly dropped from 92% to 73%, and went as low as 50% in some parts of London.

The effect was not quite as dramatic in the US, but researchers have estimated that as many as 125,000 children born in the late 1990s did not get the MMR vaccine because of Wakefield’s findings. He continues to argue his case but few still listen.

Dr Mary Ramsay, a Consultant Epidemiologist and Head of the Immunisation, Hepatitis and Blood Safety at Public Health England, said in 2019: “We have seen a number of measles outbreaks in England which are linked to ongoing large outbreaks in Europe. The majority of cases are in teenagers and young adults who missed out on their MMR vaccine when they were children.”

The latest Cochrane Library review produced by the WHO addresses the issue of Wakefield head-on.

The review highlighted two studies. One with 1,071,088 children which could find no evidence of a link between the MMR vaccines and encephalitis, inflammatory bowel disease, Crohn's disease, cognitive delay, type 1 diabetes, asthma, dermatitis/ eczema, hay fever, leukaemia, multiple sclerosis, gait disturbance and bacterial or viral infections. That’s a comprehensive list.

It also set out to re-assess the effectiveness, safety, and long- and short-term harms of the MMR vaccines following on from work it did in 2012.

“In relation to the controversy arising from false claims linking vaccination and autism, the review summarises evidence from two studies with 1,194,764 children. Diagnosed cases of autism were similar in vaccinated and unvaccinated children," state the review authors.

“We know from previous studies all around the world that the risks posed by these diseases far outweigh those of the vaccines administered to prevent them.”

Fast forward our future

Today the suspicions about the MMR vaccine have faded but still crop up in social posts now and then. For a new vaccine to challenge the COVID-19 coronavirus we could be waiting two to five years. Time consuming randomised trialling of any new agent will be essential and it is a complex and demanding process.

When, as seems likely, a spectrum of vaccines does emerge, they hopefully will not suffer from any image problem.

Author

Dermot Martin is a specialist writer and reporter on science, technology and medical research