Dr Vetja Haakuria

The current robust public discourse on vaccination, vaccine mandates and passports and the rights of citizens is a necessary conversation in a democracy. It is healthy and creates space for science to be explained and to enlighten the public on the subject. 

However, logical rationalisation is not science, there are volumes of information that underpin scientific facts. While exercising individual rights, there is a responsibility to not expose others to harm. It begs the questions: Does vaccination reduce infection among the population? Are the unvaccinated at greater risk compared to those who took the jab? These questions are best answered by addressing the role of vaccination.

On a balance of probability, there is a far greater risk of dying from Covid-19 than from being vaccinated. However, we need to make a distinction between infection, the disease (Covid-19), disease state and the causative organism of Covid-19, SARS-Cov2. Notably, one must be infected for the immune system to confer protection. This, by implication, means that vaccines do not make the virus bounce off you. Vaccines are developed against the metrics of preventing infection progressing from asymptomatic disease to mild disease, severe disease, hospitalisation or worse. As such, vaccine efficacy should be measured against these metrics. Various factors influence this progression even if one is vaccinated: old age, underlying health conditions, previous infection, genetic polymorphism etc. This explains why vaccinated people get infected in what is called breakthrough infection. However, this is by no means an indication of vaccine failure as the role of vaccines lies in the progression of that infection to a more severe state. 

For the vaccinated or survivors of SARS_Cov2 infection, the antibody-mediated immune response can neutralise the virus upon entry into the host cells with the host unaware of the infection. Those individuals are unable to transmit the virus to others. Admittedly, not everyone will have asymptomatic disease; some will progress to mild disease or severe disease and hospitalisation due to underlying health conditions such as diabetes, asthma, respiratory challenges etc. On this score, there is irrefutable empirical evidence that vaccines significantly reduce hospitalisation and admission to ICU. Real data shows that vaccinated individuals are also unlikely to develop long Covid, compared to the unvaccinated and literature to this effect abound. In a nutshell, vaccines help people survive SARS-Cov2 (Covid) infection and by implication reduce transmission of the virus to others.

While the antibody-mediated immunity wanes over time, the T-cell mediated immunity is longer lasting and becomes critical in halting progression of infection to severe disease state. Current evidence shows that protection from symptomatic disease conferred by memory T/B cells is preserved and longer lasting, hence their efficacy against variants.

So why the hesitancy about Covid vaccines?

The trajectory of vaccine development follows a set pattern of clinical trials before approval. What matters is the sample size and diversity rather than the number of years it took to produce the vaccine. There is the erroneous belief that it should take 10 to 15 years to develop a vaccine. The drug development trajectory follows the well-trodden path of Phase I - Safety and Tolerability, Phase II - Dose and Efficacy, Phase III - Treatment efficacy, Phase IV - Post marketing Surveillance (feedback from patients who take the drug). It is therefore normal for some side effects to be detected only after widespread use of a drug. Sometimes drugs get recalled from the market if serious side effects are detected after approval. What is important is that the development of a new drug goes through all the stages of development, which ensures that a large enough sample size is taken to cover all parameters that influence efficacy and safety for example age, gender, disease condition, pregnancy, other medications people are on, genetics and cultural background/race. However, this must be balanced against the need to save lives during a pandemic. In the case of a pandemic outbreak, approval is granted to fast track the development of a drug in the interest of saving lives (with checks and balances in place not to compromise patient safety). This involves balancing the risk posed by the new drug with the pandemic risk. Given that the aim is to reduce the loss of lives due to Covid-19, the risk/benefit evaluation of any new vaccine is central in the regulatory approval process. It should be borne in mind that science is evolving rapidly and advances in molecular biology and production technologies have enabled drugs to be developed in a shorter period. Traditional egg-based production of vaccines has been replaced with recombinant technologies and single-use facilities that greatly reduce development time and offer requisite flexibility.

What is in the Covid vaccines?

Drug companies submit a dossier to the regulatory body eg. (MHRA, FDA, NMRC, EMA etc.) which contains all the information on the development of the drug. Every dossier has a summary of product characteristics detailing the ingredients, dosage form, colour, contraindications, side effects etc. The summary of product characteristics for every drug, including Covid-19 vaccines, is available online.

Our robust conversation around vaccines and vaccination must be based on accurate information on drug development and its underpinning science and not on logical rationalisations, emotions, issues of rights and likes and dislikes as these introduce bias into the equation. Short of this, we’ll synchronise towards a colourful personal opinion debate devoid of the rubric and in the process drifting further away from saving lives.

* Vetja Haakuria (PhD) is a drug development scientist trained at The Advanced Centre for Biochemical Engineering (University College London, UK) and The Clinical Biomanufacturing Facility (University of Oxford, UK). Contact: haakuria@gmail.com