An employee is setting up an antibody production line in the Ibex building of Lonza in Visp, Switzerland, where part of the Moderna mRNA coronavirus vaccine is manufactured
OLIVIER MAIRE / EPA-EFE / Shuttersto
The first results of another coronavirus vaccine study are even more promising than those announced by Pfizer earlier this month. The Moderna mRNA-1273 vaccine appears to be 95 percent effective and works on those in need of protection the most – people over 65 – the US-based company announced today. The vaccine can also be kept in a regular freezer or refrigerator.
If Moderna and Pfizer vaccines really work that well, the outlook is good for other coronavirus vaccines that work in the same way, some of which are already in human studies. Such vaccines are urgently needed: almost 55 million Covid-19 cases have now been reported worldwide, with the cases increasing particularly rapidly in the United States, where more than 150,000 cases are reported per day.
More than 30,000 people in the United States aged 18 and over are participating in the Phase III study of the Moderna vaccine. Half of the participants received a placebo instead of the actual vaccine.
The interim analysis is based on the first 95 detected cases of Covid-19. Ninety of them – including 15 severe cases – were among those given the placebo and only 5 – not severe – among those given the vaccine.
The company says that the 95 people who received Covid-19 included people 65 years of age and older and 20 people “came from different communities (including 12 Hispanic or LatinX, 4 Black or African American, 3 Asian-American, and 1 multicultural ) “.
This is particularly encouraging as the results of the Pfizer and BioNTech study do not include any information on the age profiles of the participants. Therefore, it is not clear whether the vaccine has been tested and works in people over 65.
However, Anna Blakney of Imperial College London in the UK says we need more data to confirm that vaccination is effective in the elderly. “There’s no real difference in effectiveness between the two vaccines,” she says.
So far, the results also suggest that the Moderna vaccine is safe. Some participants reported pain at the injection site, tiredness, headache, and muscle or joint pain that is common after vaccinations. No serious side effects were reported.
The Moderna and Pfizer vaccines are both vaccines against messenger RNA (mRNA) – they consist of the gene that makes the spike protein that protrudes from the outside of the coronavirus. After the mRNAs enter human cells, these cells begin to produce the spike protein. The protein moves outside of these cells, where it triggers an immune response.
Three more mRNA coronavirus vaccines are already in human studies, so the prospects for these look good too. “It really holds great promise in the mRNA vaccine field in general,” says Blakney.
In addition, mRNA vaccines are easier to make than conventional vaccines, she says. “It’s just a lot easier to make to scale.”
There are also five DNA vaccines in human studies. Here the virus spike protein gene is released in the form of DNA rather than mRNA. However, unlike mRNA vaccines, specialized equipment and training are required to dose people with DNA vaccines.
There are also several adenovirus vaccines in human studies, including the one developed by AstraZeneca and Oxford University and the Russian Sputnik V. These vaccines deliver the gene for the spike protein to cells as well, but are not in fat, but in one empty adenovirus packs droplets like most mRNA and DNA vaccines.
Russia claimed Sputnik V last week that Sputnik V is 92 percent effective, but many experts say there have been too few Covid-19 cases in this process to justify this claim.
If at least some of these other vaccines prove to be as effective as they now seem much more likely, the task of vaccinating the world’s population as quickly as possible will become a lot easier.
A disadvantage of the Moderna vaccine is that each dose contains more mRNA than the Pfizer vaccine, which makes it difficult to manufacture. Still, Moderna expects 20 million doses of mRNA-1273 to be ready for shipping in the U.S. by the end of the year and plans to produce 500 million to 1 billion doses by 2021. Pfizer expects global production of up to 50 million vaccine doses in 2020 and up to 1.3 billion doses in 2021.
The mRNA vaccine developed at Imperial College London, which is expected to start phase 3 studies soon, is a so-called self-amplifying mRNA vaccine. This means that after it enters the cells, more copies of the mRNA are made. Therefore, a much lower dose is required than the Moderna and Pfizer vaccines, and it can be manufactured even faster.
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