COVID-19 Vaccines: Here’s what you should know

With COVID-19 news changing every day, it’s easy to get confused. In fact, as of November 25^th, 2020, there are more than 320 vaccines currently in development! But not all will make it to the market. To help you clear your doubts, we’re covering the key vaccines that might be rolled out in late 2020 and early 2021.

What COVID-19 vaccines are there as of November 2020?

So far, we’ve got 4 vaccines already in Phase III. This is the phase before releasing it to the public. Three of these vaccines are from labs in Europe and the US, and one is from Russia. Here’s the basic info you should know about them:

AstraZeneca/Oxford (AZD1222)

• Who makes it: This was one of the earliest vaccine candidates in development. It’s made by AstraZeneca and the University of Ox
• How it works: The vaccine uses a modified adenovirus vector to start an immune reaction. This is the cheapest vaccine offered, costing around $3 per dose.
• Development: Oxford’s vaccine was paused on September 8 because one volunteer had an adverse neurological reaction. But on October 23^rd the trial restarted and by November 23^rd, they had announced preliminary results. Phase III includes larger trials with around 30,000 people in the UK and Brazil, but these have had several issues, particularly in regards to dosage [2]. After starting trials, researchers found that a batch of vials had half the dosage. This half-dose was administered in the UK. In contrast, the Brazilian trials were carried out with the regular dosage. Surprisingly, both full-dose and half-dose results were incorporated into the latest November announcement.
• Efficiency: As of 23^rd November 2020, this vaccine had an “average efficiency” of 70% [1], with some trials resulting in as little as 62% while other groups showed up to 90%
• What other researchers say: Because of the dosage mix up and the wild differences in trials between the UK and Brazil, scientists have had some questions about its actual efficiency. Those who got the half-dose showed around 90% efficacy, but other than that the percentage sources weren’t clearly stated in the press release. What’s more concerning is that the 62% efficacy pertains to the mean between full-dosage groups in both countries. Given the dosage schemes offer very different immune outcomes, researchers question whether or not the higher efficacy is statistically robust and recommend following up with more trials.

Moderna (mRNA-1273)

• Who makes it: American biotechnology company Moderna, based in Cambridge, Massachusetts.
• How it works: Moderna’s technology is based on developing synthetic mRNA that mimics part of COVID’s protein. People will have to get two doses to be fully immunized. While this vaccine needs to be refrigerated, this can be done at a regular fridge at 36-46ºF for short-term storage, or -4ºF for up to 4 months. This is significantly easier to accomplish than temperatures required with Pfizer’s vaccine.
• Development: early on when the pandemic had just started, Moderna stated their intention to develop a vaccine using mRNA. By October 2020, there were 30,000 people signed up for Phase III trials, a similar number to Pfizer’s or AstraZeneca’s.
• Efficiency: this vaccine is being tested in around 30,000 people and reportedly has 94.5% efficiency [4], according to a preliminary study. In fact, during Phase III trials, only 5 vaccinated people developed COVID-19 while in the control group, 90 people got the virus.
• What other researchers say: No mRNA vaccine has ever been approved by the FDA because of their side effects. This falls in line with the latest reports from Moderna’s Phase III trials, where some people presented intense fever, shaking, inflammation and general COVID-like symptoms [3]. However, a full understanding of this vaccine’s side effects won’t be possible until late 2022, since Phase III trials are set to be done by early 2022.

Pfizer/ BioNTech/ Fosun Pharma (BNT162b2)

• Who makes it: BioNTech is a German-based pharma company, while Pfizer is one of the largest pharmaceutical multinationals based in the US.
• How it works: this one is also created using synthetic mRNA with sections of actual COVID-19 that won’t cause a full infection, but will give you immunity. Like in Moderna’s case, people will need 2 shots at least a few weeks apart.
• Development: initial trial phases showed immune reaction, but researchers weren’t sure about the durability of the treatment.as of November 2020, this vaccine is being tested in both the us and Germany.
• Efficiency: as of November 2020, Pfizer’s vaccine reports around 95% of efficacy.
• What other researchers say: Pfizer’s vaccine side effects can be a concern, especially as governments start rolling it out to the general populations. However, its side effects are milder than those caused by Moderna’s trials, with only 3.8% of subjects presenting fatigue, and 2% presenting headaches [3]. While these are good news, the reactivity caused by this vaccine is significantly greater than other single-dose shots.

Sputnik V (Gam-COVID-Vac)

• Who makes it: this is the so-called Russian vaccine, made by the Gamaleya Research Institute of Epidemiology and Microbiology in Moscow.
• How it works: Sputnik V uses another virus with small SARS-CoV-2 sections to create an immune reaction within the body. like the other vaccine candidates, this one needs 2 doses to reach full efficiency but this one uses different viral vectors in each dose.
• Development: the Russian ministry of health registered the Sputnik V vaccine very early, on August 2020, while it was still in Phase II. In contrast, Phase III results were only published on November 11, 2020 after re-evaluating more than 18,000 people still in trials.
• Efficiency: on November 2020 [5], Russia announced its vaccine had 91.4% of efficacy.
• What other researchers say: Because of its early approval, many researchers have doubted about its safety and efficacy. These doubts stem from the short clinical trials that lasted less than two months. But, on November 25th new data was released, showing that out of around 18,000 people vaccinated, only 39 had contracted the virus. overall, researchers think these results seem very promising but would like further trials before confirming efficiency.

Our final take

In spite of the good news, we’re not sure about which vaccine will get approved faster, and whether they will provide long-term immunity. Nevertheless, it’s nice to see these developments and know that preventing infection is closer every day.

References

1. 23 November 2020. AZD1222 vaccine met primary efficacy endpoint in preventing COVID-19. Available here.
2. Cohen, Jon. November 25, 2020. After dosing mix-up, latest COVID-19 vaccine success comes with big question mark. Science mag. Available here.
3. Wadman, Meredith. November 18, 2020. Fever, aches from Pfizer, Moderna jabs aren’t dangerous but may be intense for some. Science mag. Available here.
4. Cohen, Jon November 16, 2020. ‘Just beautiful’: Another COVID-19 vaccine, from newcomer Moderna, succeeds in large-scale trial. Science mag. Available here.
5. Kupferschmidt, Kai. With more data on its COVID-19 vaccine, Russian institute offers new evidence of success. Science mag. Available here.