December 5, 2021

I, Science

The science magazine of Imperial College

Vaccines have been revolutionary in medicine, but why are they not used in some parts of the world and how can they be improved? ...


Ouch! Wouldn’t it be great if instead of a jab with a needle, you could just eat a vaccine instead? Luckily, researchers at the University of California agree, and their attempts to use algae to produce an edible malaria vaccine is just one example of the many strides forward scientists are taking in vaccine research.

But why should we bother with vaccines at all? This can be answered with a question: which three interventions have saved the most lives globally? Clean water, adequate nutrition, and vaccination.

A striking example of the power of vaccination can be found in Meningitis A belt in Sub-Saharan Africa, where waves of the deadly disease sweep through the region every year. A severe season between 1996 and 1997 saw the disease infect 250,000 people and kill 25,000. However, since the 2010 introduction of the MenAfriVac vaccine, there have been no cases of Meningitis A in anyone who received the vaccine. This remarkable example is just one of many; we practically take it for granted that diphtheria, polio, pertussis and smallpox no longer romp freely around the UK population.

Not everyone agrees that vaccination is a good idea, though. Ever since Edward Jenner first introduced the concept of smallpox vaccination in the early 1800s, parties have rallied against vaccination on political, scientific and religious grounds. Vaccine research may have moved on, but some public opinions don’t seem to change.

In the UK, where the measles, mumps and rubella (MMR) vaccine is plentiful, free, safe and effective, should we really still be seeing measles epidemics such as that in Wales? The Welsh epidemic is not one-of-a-kind. The number of cases of measles in England and Wales has been increasing since early 2000s, with over 2000 confirmed cases of measles last year compared to barely 100 in 1999. The rise has been largely attributed to the number of unvaccinated 10-16 year olds who missed out on the MMR during the autism debate in the late 90s. In 2003 to 2004, infant MMR vaccination rates hit lows of 80%, but have since scraped back to 91%. However, despite numerous campaigns to discredit the link between MMR and autism, why is the MMR vaccination rate still not higher?

It could be down to social media. Researchers at Penn State University analysed over 300,000 vaccine-related tweets on Twitter. In an ironically similar fashion to the diseases themselves, they found that anti-vaccination sentiments were socially contagious and spread much more easily around the social network than pro-vaccination sentiments.

The human papillomavirus (HPV) vaccine uptake rates in America are also eye-watering. The HPV vaccine was recommended for all adolescent girls to prevent cervical cancer, but as of 2010, only one-third of girls had been immunized against HPV. Despite the increasing number of studies showing the HPV vaccine to be safe and efficacious, parents seemed increasingly discouraged. Five years ago, 40% of parents said they wouldn’t vaccinate their daughter against HPV. In 2010, that figure rose to 44%. It seems that in some cases, not only are opinions not being swayed in favour of vaccination; they’re actually heading in the opposite direction.

The recent failures of a key HIV vaccine, HVTN 505, and the Bill and Melinda Gates Foundation’s malarial vaccine, RTS,S/AS01, to show efficacy in trials dealt bitter blows to the vaccine community. However, the very fact that scientists are frustrated by these results just goes to show how much they believe in the impossible. This is the Decade of Vaccines, and there’s real hope that developments will protect billions of at-risk individuals around the world. However, it seems we have to look further than just creating the perfect vaccine. We have to get the vaccine to the people who need it, against cultural, geographic and economic barriers. Science needs to get creative and imaginative, and bring vaccines to the real world and not just a laboratory.

This is where research like freeze-dried edible algae comes in – and it’s more than about making vaccination painless. Imagine you’ve just created a vaccine for malaria. Great! But, how do you get your vaccine from your laboratory in Cambridge to the deepest tropical regions of the world? For a start, all those single-use needles and syringes are relatively heavy and expensive. Then it’s likely that your vaccine formulation needs to be kept cool, which is unfortunate as your target population probably live in warm climates. Even when you’ve hauled your refrigerated vaccine there, who’s going to administer it? If algae could be engineered to produce your vaccine – be that for malaria, cholera or another global killer – then it could be grown in water anywhere around the world.

Vaccination is about more than just sore arms. It’s the closest thing to invincibility we’ve ever invented, and maybe one day you could grow it in your bathtub.

IMAGE: WikiCommons