“Today’s Emergency Use Authorisation in the UK marks a historic moment in the fight against Covid-19,” said Pfizer CEO Albert Bourla. It is indeed historic as it has been developed in record time and is the first vaccine based on messenger RNA or mRNA technology approved for human use.
A mRNA vaccine against Covid-19 virus
The covid-19 mRNA vaccine, once injected, will give instructions to our cells to make a harmless piece of what is called the “spike protein.” After the protein piece is made, the cell breaks down the instructions and gets rid of them. Our immune systems recognize that the protein doesn’t belong there and begin building an immune response and making antibodies, similar to what happens in natural infection against Covid-19.
Until now no commercially available vaccine or drugs used this platform and has never been tested on large-scale human trials. Moderna’s mRNA 1273 which is claimed to be 94.1% effective in preventing Covid infection is also based on the same technology. The company has also requested for EUA, “Moderna’s data for the Emergency Use Authorization request for mRNA-1273 has been submitted to the U.S. FDA,” Moderna said in a recent tweet.
Impact of Emergency Use Authorization during a health crisis
Emergency use authorization (EUA ) enables interim approval to a medical product in an emergency (like the Covid pandemic) if there is sufficient evidence suggesting its safety and effectiveness. The final approval is granted only after the completion of the trails and analysis of the full data; until then a EUA allows the medicine or the vaccine to be used on the public.
EUA is an important tool for public health officials and physicians involved in an emergency response because it can enable them to use the best countermeasure available to detect, prevent, or treat a disease or injury in certain populations, even if that countermeasure is unapproved by the Food and Drug Administration (FDA) or not approved for that particular use.
For Covid vaccines, the FDA had stated that it would consider an application for EUA only if the phase 3 clinical trial data showed at least 50% effective in preventing the disease.
In November, the US pharma giant Pfizer and its German biotech partner announced that final data analysis of the late-stage trial found the vaccine to be 95% effective.
The final analysis evaluated 170 confirmed Covid infections among 43,661 participants, out of which 162 cases of Covid were observed in the placebo group versus just eight cases observed in the group that received the two-dose vaccine. Pfizer also stated that no serious safety concerns related to the vaccine were reported. The only severe side effects to occur in more than 2% of people were fatigue, which occurred in 3.7% of patients after the second dose, and headache, which occurred in 2%.
According to the GlobalData’s Senior Infectious Diseases Analyst, Philipp Rosenbaum, “The UK represents an ideal test bed for the delivery of Pfizer’s vaccine. The country’s small size, dense population and strong healthcare infrastructure should mean distribution of the vaccine with cold-chain should go smoothly. If problems do arise, this will not bode well for distribution in countries with longer distances to vaccine distribution centers – not even mentioning countries with less developed infrastructure, or sparse and ill-equipped healthcare centers.”
Reduce logistical challenges
The Pfizer-BioNTech vaccine must be stored and transported at about -70C, making it a major challenge. Addressing the concerns raised on maintaining the extremely cold temperatures required to assure the quality of vaccine, it said, “Companies have developed specially designed, temperature-controlled shippers for the BNT162b2 vaccine candidate, which can maintain recommended storage conditions (-70°C ±10°C) for extended periods of time without any additional equipment but dry ice.”
“The shipper can maintain temperature for 10 days unopened which allows for transportation to markets globally. Once open, a vaccination center may use the specially designed shippers as a temporary storage solution to maintain the recommended storage conditions (-70°C ±10°C) up to 30 days with re-icing every five days in accordance with the handling instructions. Each shipper contains a GPS-enabled thermal sensor to track the location and temperature of each vaccine shipment 24 hours a day, seven days a week. Once thawed, the vaccine vial can be stored for up to five days at refrigerated (2-8°C) conditions,” the companies said in a statement.
The first doses of the vaccine are expected to arrive in UK in the coming days. Pfizer and BioNTech under their agreement with the UK will supply 40 million doses, delivery of which will occur throughout 2020-2021.