A glimmer of hope
On November 9th and 16th, Pfizer and Moderna respectively announced the results of their COVID-19 vaccine trials. Both presented extremely positive outcomes which have given the world twin rays of hope in these dark days. Pfizer claims “more than 90%” efficacy compared with Moderna’s stellar 94.5%. These are surprisingly strong results, which, if upheld by data in large scale vaccinations, should materially change the trajectory of the long battle against the virus.
Akiko Iwasaki, an immunologist from Yale University lauded the results. “This is really a spectacular number,” Iwasaki stated. “I wasn’t expecting it to be this high. I was preparing myself for something like 55 percent.” Dr. Anthony Fauci, who leads CD<, added, „It’s just as good as it gets — 94.5 percent is truly outstanding.” The relevance of this discovery is extremely promising, given that most scientists were predicting numbers similar to flu vaccine efficacy rates of 40-60%. Through a mass-scale vaccination program utilizing vaccines with 90%-plus efficacy, it is now realistic to hope we can break the transmission cycle of the virus.
Both vaccines are administered via two shots. Pfizer’s are given with a 3-week interval in-between; Moderna’s are done 28 days apart. Pfizer’s vaccine must be stored at -70 Celsius for safe shipping and storage, but can last up to five days at standard refrigerator temperature or 15 days in a thermal shipping box. Moderna’s vaccine, by contrast, requires only standard fridge temperatures (2 to 8 Celsius) and remains effective for up to 30 days in that environment, or it can be stored up to 6 months at -20 Celsius.
Many burning questions remain. In particular, how long does immunity provided by the vaccine last? The answer to this will surely determine whether we can expect a serious “third wave” or smaller, localized spikes. In terms of side effects, Moderna’s vaccine has caused severe aches and pains after the second dose among ~1/5 of the volunteers who took it. 10% of volunteers experienced fatigue severe enough to interfere with their daily activities. Most of these complaints, fortunately, were apparently short lived. According to Peter Openshaw, a professor of experimental medicine at Imperial College London, “These effects are what we would expect with a vaccine that is working and inducing a good immune response.”
Moderna’s vaccine, developed as part of Operation Warp Speed, relied on governmental funding and its availability should reach 20 million doses by the end of the year. Pfizer did not accept any government grants and claims the ability to deliver 15-20 million doses, also by the year end. The first batches are expected to be rationed for healthcare staff. The US might have access to more than 1 billion doses of both vaccines in 2021.
Both companies are preparing final documents requesting Emergency Use Authorization, and the FDA is widely expected to grant these approvals faster than usual. However, Dr. Fauci has cautioned the general public that even if the nation sees a vaccine by April 2021, “this does not mean that in April, everybody who’s going to be wanting a vaccine, who’s not in the priority group, is going to get it.”
These data points suggest that the combination of immunity developed by those who have recovered from COVID and those with immunity stimulated by the vaccine may help stop the spread of the virus and get us closer to normality in the second half of 2021.
Sources: Axios, NY Times, 23andme.com, CDC, Pfizer and Modern’s press releases