The announcement sent the pandemic news mill into overdrive, coming on the heels of last week’s announcement by the Pfizer/BioNTech team that its BNT162b2 Covid-19 candidate was “more than 90%” effective.

Moderna said it is on track to have about 20 million doses of its vaccine ready to ship within the US by the end of 2020 and expects to be able to produce 500 million to 1 billion doses by the end of 2021. Pfizer-BioNTech plan similar volumes.  Both developers’ vaccines are given in two doses several weeks apart.

In Moderna's US trial, 90 of the 15,000 of the study participants who were given a placebo over a period of several months developed Covid-19, inc1uding 11 who had severe forms of the disease. Among the 15,000 receiving the vaccine, only five contracted the virus, and none became severely ill.

The US biotech said its candidate did not have any serious side effects, although a “small percentage” of those receiving it reported symptoms such as body aches and headaches.

Moderna plans to apply to the US Food and Drug Administration (FDA) for an Emergency Use Authorization (EUA) toward the end of the month after accumulating more safety data. The US-German team said last week it could apply for an EUA before the end of November.

Both vaccine developers’ candidates are based on the messenger RNA (mRNA) model. German biotech Cure Vac also is working this type. As yet, no Phase 3 data is available for the non-genetically engineered candidates being developed by companies or partnerships such as Johnson & Johnson’s Janssen arm, AstraZeneca/Oxford University or Sanofi/GlaxoSmithKline.

From this week’s perspective, Moderna seems to have a slight edge on Pfizer-BioTech on the medical world’s favorability scale, which does not reflect the minimal percentage difference in efficacy – if there is any – between the two candidates but rather the company’s apparent logistical advantage.

While the Pfizer-BioNTech candidate must be kept at a constant temperature of minus 70° Celsius, Moderna’s requires an easier to handle minus 20°C. This is the same temperature the commonly used chickenpox vaccine requires, meaning that the same refrigeration equipment can be used.

According to reports, no other vaccine requires such a low temperature as the German-American product, and the traditional US cold chain equipment is ill equipped to handle it. Moderna's product, in contrst, can be kept for 30 days in a refrigerator and is stable for 12 hours at room temperature. The Pfizer-BioNTech candidate can last only five days in a standard refrigerator.

Leveraging the strength of its worldwide distribution chain, Pfizer is trying to  overcome its potential difficulties by setting up its own system to deliver the vaccine directly to healthcare providers, The pharma giant is reportedly building distribution hubs in the state of Wisconsin for the US and in Germany for Europe.

The mRNA vaccine candidate CVnCoV, now in Phase w2 trials at CureVac could have a stability profile more advantageous than its two mRNA rivals, it appears. The German biotech said the vaccine remains stable and within defined specifications for at least three months, when stored at a standard refrigerator temperature of +5°C and that  it also remains stable up to 24 hours as a ready-to-use vaccine when stored at room temperature.

In the US, infectious diseases expert Anthony Fauci, head of the National Institute of Allergy and Infectious Diseases NIAID, which has collaborated with Moderna on the development of its vaccine, said inoculation could begin in the second half of December, starting with high-risk groups, and the rest of the population could follow next spring.

Fauci said the successful trials of the first two candidates appear to “really validate” the mRNA platform, which has never been used for a commercial vaccine to date.

Author: Dede Williams, Freelance Journalist