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Scientists search frantically for a safe and effective SARS-CoV-2 vaccine. Covid is rampaging the world, leaving a trail of devastation, but there may be a definite end in sight as multiple companies are racing to test their vaccine in hope of finding one as soon as possible.
The impact of COVID-19
Covid poses a significant risk to safety, health and wellbeing, disruption to people’s socioeconomic welfare, and will no doubt leave a global mental health problem that will take some time to set right again. But it is in the capable hands of our scientific communities that we seek a cure to save the world from Coronavirus. That can only be achieved through the safe manufacturing and disruption of a working vaccine or medical treatment.
How is a vaccine made?
A vaccine’s development starts in the laboratory. To create an effective vaccine, scientists first need to understand the disease in question.
The aim is to create a vaccine that gives long-lasting immunity to a pathogen while also keeping the person safe. Vaccines contain both antigens, (small amounts of weakened or dead germs) and adjuvants (substances that can boost the immune system’s response). In simple terms, a vaccine is when a virus is weakened, then given to the human, as it’s a diluted version, it won’t be able to reproduce enough times to cause the virus but replicate well enough to induce “memory B cells” that protect against infection in the future. For the Coronavirus, vaccines are being trialled under several different approaches; active, inactivated, DNA, RNA/mRNA-based, virus vectors and protein subunits. Regardless of approach, all vaccines require regulatory approval before market.
Understanding the COVID clinical trial process
The first goal of phase I and II clinical trials is to evaluate short-term safety, check the dosage and assess aspects of the body’s reaction to the vaccine — effects known as reactogenicity (redness, pain, swelling at the vaccine site)
The second objective of these early-stage clinical trials is to assess immunogenicity — the ability of a vaccine to stimulate a detectable immune response to the vaccine target.
Of interest will be the vaccine-specific antibody response and immune cells named CD4 (or helper) T cells and CD8 (cytotoxic) T cells. These T cells directly target cells infected with the virus or join with antibody-producing B cells. The best vaccines give long-lasting responses that produce neutralising antibodies, which act to prevent an infectious agent from causing illness.
Once the first two phases of the trials have been completed, phase III of the study can be conducted. This stage determines whether the vaccine affects how susceptible people are to disease.
Progress with COVID vaccine
Trials need to show that a vaccine is safe for use in humans, both short-term and long-term. They also need to show that they provoke an immune response prior to end-stage development, manufacturing and approval from medicines regulators.
Research is happening all over the world at great speed. Approximately 240 vaccines are in early development, with 40 in clinical trials and nine in the final stage of testing.
- The Oxford vaccine shows promise, triggering an immune response that looks strong enough to progress to the next stage of vaccine development.
- The first human trial data conducted back in May demonstrated how the first eight participants in this US study all produced antibodies that could neutralise the virus.
- An exciting trial using viral proteins to develop an immune response is underway.
- Several other novel approaches are currently in human trials.
However, no-one knows how effective any of these vaccines will be, and so further studies will be needed.
These are just two of the world’s front runners:
ChAdOx1 nCoV-19: AstraZeneca & Oxford University
ChAdOx1 nCoV-19 is a viral vector vaccine currently in Phase 3 of trials. Initial results from Phase l and Phase ll show the vaccine can trigger a robust immune response, producing antibodies and T-cell responses in the test group.
BNT162b2: Pfizer & BioNTech
BNT162b2 is a messenger RNA (mRNA) vaccine from American-German duo Pfizer and BioNTech is currently in Phase 3 trials. Initial testing in the first two phases showed the vaccine produced antibodies and T-cell responses specific to the SARS-CoV-2 protein. Developers claim they could know by the end of October if the vaccine works or not and possibly, have enough data to determine its safety by the end of November.
Until we have a working safe vaccine we must all protect each other and stay safe, social distance, wash our hands, remember good cough etiquette, and wear our masks. This will end, we will see normality again, in the meantime lets stay positive as we await a successful and welcomed COVID-19 vaccine.