Nine months into the COVID-19 pandemic, vaccines are in sight. That’s right, plural, vaccines.
Recently, three companies released some results from their Phase III studies, reporting effectiveness ranging from 70 to 95%. They are Pfizer/BioNTech, AstraZeneca and Moderna.
Pfizer and Moderna have formally applied to the FDA for emergency use authorization (EUA). The FDA will review Pfizer’s request Dec. 10 and Moderna’s Dec. 17.
Earlier this year, the FDA issued guidance on COVID-19 vaccines applying for emergency use authorizations, saying a vaccine must be at least 50% effective to get OK’d. So the 70 to 95% success rates are being hailed as preliminary good news by experts.
Even better news for those over 60: The vaccines appear to work in older adults, whose immune systems naturally decline. For instance, Pfizer found in a Phase III study including about 44,000 people that the vaccine effectiveness rate was over 94% in those over age 65, very close to its 95% overall rate.
Astra Zeneca says its vaccine is better tolerated in older than younger people. Some of their results have been criticized—they found a 90% efficacy in a small group but a 62% in a larger group and simply averaged the figures at 70%. The company is intending to release more data.
How Do the Vaccines work?
The vaccines from Pfizer and Moderna use a new approach known as messenger RNA or mRNA. Instead of injecting a weakened or inactivated germ into the body, the vaccine teaches cells how to make a protein or piece of a protein that triggers an immune response. The response produces antibodies, which protect us when the real virus shows up.
AstraZeneca‘s vaccine is made from a weakened version of a common cold virus taken from chimpanzees and genetically altered. The vaccine carries the blueprint for the coronavirus’ spike protein to the body; the immune system produces antibodies to it and is then ready to attack the real virus if the person is exposed.
Wait, there’s more
There are some caveats. Recently, doctors gathered at a CDC meeting cautioned that people need to know that there are side effects from the vaccines (sore arms, muscle pain, chills). That’s important to know so those who get vaccinated will know what to expect—and return for the second dose most of the vaccines require.
Senior Planet reached out to two infectious disease experts; both are cautiously optimistic about the vaccines and their effectiveness in older adults. “So far a limited amount of data looks encouraging in older populations, but we need to see more data in detailed form, including adverse events,” says Amesh Adalja, MD, senior scholar at the Johns Hopkins Center for Health Security. Litjen (LJ) Tan, PhD, chief strategy officer at Immunization Action, agrees, saying more detailed results are needed.
Who’s First? To Be Determined
A panel advising the CDC voted Dec. 1 that health care workers should get the vaccine first, followed by residents of long-term care facilities. Essential workers and older adults are expected to follow soon after.
Photo by Obi Onyeador for Unsplash