A dose of joy

On December 8, the world took a glimpse of the future and it looked like a frail 90-year-old woman with flaxen hair sitting in a doctor’s office. Margaret Keenan became the first person to receive the Covid-19 vaccine developed by Pfizer and Biontech, a week after UK regulators approved the jab for emergency use.

It was a moment everyone had been waiting impatiently for since the start of the outbreak even while experts and governments were doing their best not to raise expectations unnecessarily. The development of the vaccine in record-time was itself an achievement of science and collaboration and by the time Keenan was administered her dose, three projects had already announced successful completion of their trial processes. Another 18 were in phase-three testing.

This flurry of vaccines demonstrates not only the dynamism of researchers and the pharmaceutical sector, but the creative force that the scientific community is. In January, the entire genome of the corona virus was sequenced and made publicly available, a feat that allowed scientists to identify the protein that the coronavirus uses to bind to receptors that usher it inside the cell.

Pfizer/biontech was the first to announce phase-three results in early November, sending a spontaneous wave of celebration across the globe. The impressive results showing 90 percent effectiveness was closely followed by the Moderna trial conclusions, achieving nearly 95 percent effectiveness. Both teams were working with an innovative technology known as Messenger RNA (MRNA). Traditionally, vaccines introduce modified versions of a virus to teach the body how to fight a particular disease in the future. This approach has proved fairly adequate in the last 70 years and it is estimated that up to three million lives are saved annually from inoculation. Producing these vaccines, however, is a long process and, many times, resource intensive.

RNA vaccines, by contrast, can be created within days and modified along the way if scientists observe mutations in the virus. MRNA vaccines such as those developed by Moderna and Pfizer/biontech encode molecules with a sequence that, when injected, instruct immune cells to mimic the pathogen, triggering the body to develop its own defence system. The downside to this approach is that vaccines need to be stored in extremely low temperatures ranging between -20°C and -70°C, making it more difficult for countries without the right infrastructure in place.

An alternative solution developed by Oxford University and Astrazeneca is a DNA vaccine that can be stored in a regular refrigerator. Moreover, the pharmaceutical company has committed to sell the product at cost price for the duration of the pandemic, bringing its price down to less than a quarter of the other two RNA vaccines.

The Oxford-astrazeneca technique introduces a re-engineered DNA of the virus into the body which the cells then transcribe into RNA to induce the needed immunogenic response. The relative low cost and durability of this approach makes it a complementary solution to the global vaccination programme, but the project has been slowed down by a series of questions over the reliability of its testing.

The partners trialled the experimental vaccine in Brazil and the UK, but while the former cohort registered an effectiveness rate of 62 percent, results shot up to 90 percent in the latter. It was later discovered that participants in the UK had been given a half-dose in their first injection, not the regular full one. Although the findings suggest that the incident may prove to be serendipitous, other tests in the US had to be suspended while an investigation was launched.

On the plus side, participants in the Oxford-astrazeneca project were routinely swabbed for coronavirus so effectiveness in their case means that the vaccine prevents infections and transmissions. The solutions proposed by Moderna and Pfizer/biontech can so far only reliably indicate that they prevent the disease and its symptoms.

The announcement of the vaccine was indeed a moment of cheer. Many leaders have trumpeted it as the beginning of the end of the virus, even if the vaccine will take long months to reach the entire global population. But even if no one has received the full double-dose yet, news of the vaccine has injected a sense of comfort and hope in the world as it looks forward to 2021.