Vaccinations, human health and the anti-vaccine movement

Vaccinations, human health and the anti-vaccine movement

26 November 2020
By Lila Touabi, School of Human Sciences

Once again, London Met interdisciplinary research forum returned after a break for the summer. The event was led by professor Gary McLean of the School of Human Sciences and covered a variety of areas about different types of vaccines and vaccine-related topics for a wide audience range – among them researchers, lecturers and students from different schools and disciplines of London Metropolitan University. The forum welcomed three expert speakers from different areas:

  • infectious diseases, particularly viruses, immunology and public health – Prof Gary McLean (School of Human Sciences – London Met), who covered the overview and introduction to the session.
  • Dr Matt Reeves (University College London – UCL) and Dr Jon Kennedy (Queen Mary University of London) then covered a range of topics on vaccine development and vaccine uptake dynamics in populations. It is topical at the moment to discuss vaccines during the COVID-19 pandemic. Particularly as there is a spread of misinformation about COVID-19 vaccines and some negative voices are raised on anti-vaccine and conspiracy theories.

Years ago, measles was huge global problem. It is a very infectious virus which can be easily transmitted through the airborne route similarly to SARS-CoV-2. It is very easy for this virus to spread among the population and every year half a million cases were reported to the authorities until 1970s when the vaccine was introduced. Unfortunately, COVID-19 has significantly higher case rate than that. However, the measles vaccine was a huge success; measles cases have fallen significantly and almost a complete loss by 1997. Vaccines are critical for saving lives and reducing infectious disease burdens, they have been shown to protect us against diseases since the 1950s and first the successful eradication of a human infectious disease due to vaccination for smallpox was achieved in 1980. Currently there are in total 26 vaccines available and they all have shown a huge success in controlling devastating infectious diseases such as malaria, hepatitis A and B, typhoid, influenza, and rubella.

From a molecular and biological perspective vaccines are antigenic preparations that stimulate a protective immune response to one or more specific pathogen either viruses, bacteria, fungi or parasites. It is very important that the vaccine will be safe to use, provide long-lasting immunity, are easily administered and affordable to the population. Up to now there are several different types of vaccines licensed for use in humans:

Live attenuated viruses: classic strategy (eg polio/measles), this contains replicating virus – it gives better immunity, it is unlikely to cause disease in healthy individuals, but it can be dangerous for people with weakened immunity as it can cause disease.

Inactivated vaccines: contain viruses and bacteria which have been killed so they do not cause any damage. The only problem with inactivated vaccines is that they do not tend to afford long-lasting immunity especially for people with weakened immune systems, so they require repeated doses. An example for inactivated vaccine is the SARS-CoV-2 (Sinovac) from China. It is shown to be completely safe, however; people who take this vaccine may have to do repeated doses over time to boost immune response.

There is also a subunit vaccine which are the most used in the UK, they do not contain any live viruses or bacteria, they are safe, they do not cause disease; they contain proteins from the surface of bacteria or viruses. Even though the vaccine might only contain a few out of the many proteins of a virus, they are enough in themselves to trigger an immune response which can protect against the disease.

Vector subunit: this vaccine is based on delivering the target gene encoding the immunogenic protein by using another virus. This vaccine is safe and gives a better activation of the immune system, for example, the genetic vaccine for SARS-CoV-2 produced by Oxford/AstraZeneca (UK) uses a non-replicating viral vector containing the SARS-CoV-2 spike gene.

Nucleic acid based sequences of viral proteins: the advantage with these vaccine platforms is that they are safe and quick to manufacture and stimulate the immune response, examples include Moderna NIAID (USA) that contains spike mRNA of the virus with lipid nanoparticles, Inovio (USA) contains spike DNA and the bioNTech/ Pfizer (USA) which contains spike mRNA; these vaccines appear to be 95% effective at preventing SARS-CoV-2 severe disease.

So, what do we need for developing a vaccine?

First, we need a target pathogen. It can be either virus or bacteria etc, which are the drivers that cause disease, as we know 60% of emerging diseases come from animals (HIV from chimpanzee, Ebola from bats, influenza from birds and pigs). Secondly, we need immune systems that respond to and fight these pathogens. We also need a strategy on how we build a vaccine and finally lot of funding, as a lot of money is required to develop a vaccine quickly and that is the case with SARS-CoV-2 vaccines.

Some people ask why SARS-CoV-2 vaccine was developed so quickly, considering that it is a new virus. It is true the clinical trials have been rapid, but the strategy of mRNA vaccination is not new in research, as it was used for other viruses such as HIV and they have elicited potent immunity against influenza, zika virus, rabies virus in animal models. Other mRNA cancer vaccines have been through numerous cancer clinical trials. The main reason for the SARS-CoV-2 vaccine success is the availability of huge amount of funds and rapid application to existing vaccine platforms that only require sequence information and do not need growth of large amounts of virus.

Pfizer SARS-CoV-2 vaccine has 95% efficacy and is safe, however, further analysis shows although the vaccine is effective and safe in clinical conditions, not everyone is willing to take it. There is plenty of evidence suggesting we should be concerned about this. 27% of people in the USA would probably not or definitely not get the SARS-CoV-2 vaccine (Pew 2020) and 1/6 people in UK say they are unlikely to or definitely will not get the vaccine (KCL 2020). France has the highest rate of vaccine hesitancy – 1/3 believe that the SARS-CoV-2 vaccine is unsafe.

So what is driving vaccine hesitancy?

The cause of vaccine hesitancy is complex and context specific, varying across time, place and the vaccine. According to Dr Jon Kennedy (QMUL), scientific populism is more likely to be driven by a similar feeling to political populism. A study, published in the European Journal of Public Health, looked at the percentage of people who voted for populist parties in 14 European countries, and people who believe vaccines are unsafe. They showed a strong correlation between populism and vaccine hesitancy. Adding to that, Dr Kennedy also revealed that vaccine hesitancy is drawn to the now retracted and false Andrew Wakefield article in 1998 which linked measles, mumps, rubella vaccine to autism.

No doubt we live in interesting and difficult times with the coronavirus pandemic and whilst the SARS-CoV-2 vaccine rollout is considered critical for exit, extreme challenges lay ahead to ensure the largest number of people globally receive this life-saving intervention.