BRUSSELS, Dec 18 – Vaccination should be thought of as a tool that teaches your powerful immune system how to fight infection so that you don’t get very sick, says a vaccine expert.
Dr Mark Fletcher, who is Emerging Markets, Medical & Scientific Affairs Lead for Respiratory Vaccines at Pfizer Inc., sought to explain how vaccination works as a natural process for the human body to counter the pervasive “military” concept of immunisation.
“It’s not a war to destroy viruses and bacteria; it’s more gentle and kind, peace and love,” Dr Fletcher told a Pfizer vaccines educational media session organised by the global pharmaceutical company for journalists from Asian media outlets in the Belgium capital of Brussels last October 24.
“For most vaccine-preventable diseases, what we want is a state of equilibrium with the virus or the bacteria. We don’t want to eliminate the virus or bacteria.
“We simply want to make sure that the potential dose is strong enough so that when infection comes, your immune system has been trained and educated.
“And you can help your body to handle that infection in a much more gentle way – maybe in a mild or short-term form of the disease – so that you don’t have the severe or deadly form of the disease.
“That’s what vaccines do – they put that equilibrium or balance of nature on the side of the host.”
Dr Fletcher explained that immunisation isn’t like a “big tank” rolling down to wipe out every infectious disease in mankind, but to “readjust the rules of the game” so that human beings are stronger in case infection comes.
“I insist on that point because we often use concepts about vaccination which are a little military, right? They’re a little brutal. They’re a little harsh and I think we need to appreciate that with vaccinations, it’s a completely natural approach.”
He pointed out that even breathing or eating meals can be an act of self-immunisation, as there are immune cells in the intestine.
In an interview with CodeBlue at the sidelines of the Pfizer vaccines educational media session, Dr Fletcher explained that vaccines are designed to awaken one’s immune system so that when one is exposed to a pathogen, the initial immune response occurs quicker.
“You may have the initial signs and symptoms of the infection, but by then, your immune system has woken up. There’s always a gap between exposure and reaction from your immune system. That gap is shortened because of memory from the vaccine, so that the more serious outcomes are attenuated.”
Hence, vaccination helps prevent hospitalisation or death from complicated outcomes of the initial infection, with one getting just mild symptoms as the immune system – having been primed and knows how to deal with the virus or bacteria – handily and naturally prevents the full extent of the infection.
“I always try to help people appreciate that this is a natural mechanism and all we’re doing with vaccination is we’re just creating this memory, you know, just like when you learn a song or you learn a poem.
“We’re creating this memory so that when the signal comes, the body doesn’t need time to learn quickly and then get ready. The body’s already been primed. That’s why we talk about priming and boosting the body that’s already primed. Then, when the virus or the bacteria comes and the infection begins, the body can respond much more quickly.
“That’s what I mean about ‘natural’. The natural part is just about shortening the reaction time and then attenuating the extent of the infection.”
Dr Fletcher also noted that people tend to underestimate the power of the immune system, as the effectiveness of a vaccine is usually measured in linear terms, like it is X per cent effective.
“In fact, for nature and the immune system, it’s about leaps and bounds. It’s about logarithms – two-fold, 10-fold, 100-fold increases,” he said.
“What’s really remarkable is that vaccination primes you and the reason why you can respond more quickly and more effectively is not because in your immune system, there’s one memory cell, then two, then three, four, five – that’s a simple linear increase – but it’s actually one, two, four, eight.
“So very quickly, you’ve got this exponential growth. I think that also is often underappreciated about why the immune system is so effective.”
The vaccine expert gave an example of getting a flu shot before one gets infected later, saying that while the immune system is growing exponentially, one gets a sore throat, runny nose, and headache from a flu infection.
“You say, ‘oh, the vaccine doesn’t work’. What you don’t realise is that you may have ended up in the hospital or you may have died. People say, ‘I took the shot, but then I got the flu’.
“What they think is the flu is the fact that they had scratchy eyes and a runny nose, and they were a little tired for two days. What they don’t realise is what they missed out on – which was being really sick.”
Dr Fletcher stressed that with vaccination, it’s really the immune system that does all the work, rather than the vaccine itself.
Pfizer Inc currently focuses on three vaccine technology platforms – subunit vaccines like the respiratory syncytial virus (RSV) vaccine, mRNA vaccines like the Covid-19 vaccine, and conjugate vaccines like the pneumococcal vaccine – according to Dr Fletcher’s presentation at the October educational media session.
The US-based pharmaceutical company’s active vaccine trials, across different stages, include an mRNA combination Covid-19 and flu vaccine, an mRNA influenza vaccine, and an mRNA shingles vaccine, as well as an RSV maternal vaccine and an RSV adult vaccine.
Data on both RSV vaccines have been submitted after Phase Three trials, while the mRNA influenza vaccine is currently undergoing Phase Three. Both the mRNA shingles and mRNA combination Covid/ flu vaccine are still in Phase One.
For the bacterial category, data on Pfizer’s meningococcal vaccine has been submitted after Phase Three trials. Its C. Difficile vaccine is in Phase Three, while Pfizer’s pneumococcal (paediatric) vaccine and Group B Streptococcus (maternal) vaccine are currently in Phase Two.
For tick-borne diseases, Pfizer’s vaccine for Lyme disease is in Phase Three.
Dr Fletcher told the educational media session that vaccines are needed for every stage in life, not just childhood, to deal with infectious disease outbreaks, travel to new places with local infections that one is not immune to, or old age when one becomes more susceptible to diseases. An example is the flu shot.
Vaccines, he said, are on par with access to clean water and good sanitation that are essential public health measures.
“The people who work in sewers are, in some ways, as important as us who work in vaccines.”
