COVID 19 variants
How British Scientists Found the More Infectious Coronavirus Variant
"One mutation the patient had, labeled 69-70del, changes the shape of the spike protein. Another, N501Y, can help the protein bind more tightly to human cells."
"Eventually, British scientists detected 23 mutations that distinguished these genomes from the earliest known version in Wuhan, China — enough to be a considered a new variant, since labeled B.1.1.7."
"The variant is now estimated to account for more than 80 percent of
positive cases in London and at least a quarter of infections elsewhere
in England, and has turned up in more than 50 countries." (from Jan 22, 2021)
Vaccine reserve was exhausted when Trump administration vowed to release it, dashing hopes of expanded access
When study participants were given both shots at intended dose (it is a two shot series), efficacy was around 62% (62% of people were protected from COVID, need more info about how that is defined). When the first dose was accidentally given at half intended dose, but second dose was full dose, efficacy was 90%. More studies being done to see if this difference in efficacy is real, and if so, why. For now AZ is combing the results and claiming vaccine is about 70% effective overall. This vaccine is less expensive than other front runners and requires less extreme cold storage (this introduces a lot of logistical challenges for other vaccines that require storage at much colder temperatures).
This vaccine was developed via a partnership between BioEntech (a German company) and Pfizer. Results were recently reported for the phase 3 trial, which was a randomized controlled trial with 44,000 participants. Half of the subjects were given the vaccine and half were given a placebo (which was not a placebo). At the end of the trial (how long was the trial?) 94 subjects had confirmed cases of coronavirus (how were cases confirmed?). Much of the information about this trial has not been released yet (as of early November), but it has been calculated that if the effectiveness that was reported of around 90% (why is this different than the 95% figure given elsewhere?) than no more than 9 of the 94 subjects who got sick were given the vaccine. Final approval will be considered once the number of test subjects who get infected reaches 164. With such a brief period of study, and without more details about the trial, it is still to be seen whether the effectiveness rate is consistent in different populations, what long-term consequences and side effects there will be, how long the acquired immunity will last, whether it will prevent people from being able to transmit the virus to others. Pfizer says they will be able to make enough vaccine for 650 million people by the end of 2021 which isn't nearly enough for the global need. It is estimated that around 4 billion people globally will need to be vaccinated in order to reach herd immunity.
This vaccine was designed to introduce particles of mRNA (messenger RNA), the molecule that carries genetic information from the DNA to the organelle in the cell called a ribosome, which than makes the protein that the mRNA strand codes for. In this case the mRNA contains instructions for making the spike protein which is on the surface of the virus and allows the virus to enter cells and cause infection. The idea is that the body will than use these spike proteins to make antibodies against the virus so that the body can fight off the real virus more effectively when it encounters it in the future. It is claimed that this vaccine could be altered relatively easily to fight additional versions of the virus created when mutations happen (which they already have).
The Pfizer vaccine needs to be administered as two doses, given 21 days apart. It also needs to be kept at -94 degrees F, which introduces serious logistical problems. It can be stored at that ultra low temperature for as long as 6 months, but also kept at 35 to 46 degrees for up to 5 days. The company reports that if the vaccine warms up too much, the mRNA particles change shape and become ineffective. In much of the world there simply is not enough resources to store the vaccine at this low temperature. Even in the US few hospitals have the kind of freezers that can do this. Dry ice can be used, but that is only a temporary measure until it melts and getting more of it to where it is needed is problematic for the same reason that transporting the vaccine is in the first place. The type of freezer required for storage at such cold temperatures cost around $10 K to $15 each. Here in the US many hospitals have been operating at a loss for much of the pandemic so the high cost is a significant
This vaccine also needs to be kept at a lower temperature than usual for vaccines, although the -4 degrees F it requires makes the logistics of transporting and storing it less problematic.
Regeneron is a monoclonal antibody cocktail. They took antibodies from recovered patients and made more, and combines two different antibodies. Helps keep the disease more mild, intended to reduce need for hospitalization and intensive care. Needs to be used early in disease to help.
Beracitinib is an anti-inflammatory medicine. Is used in combination with Remdesivir. This combo helps people who are already on oxygen avoid more serious complications of the disease.
Survival rates have improved.