All three vaccines are very similar, and leverage similar technology to proffer immunity, ultimately teaching the body how to produce, recognize, and destroy spike proteins. Coronavirus is encased in spike proteins that help it latch onto the body’s cells. Following vaccine-induced immunity, your immune system can recognize and neutralize these spike proteins, preventing infection.
Pfizer’s vaccine is provided in two doses three weeks apart and must be stored in very cold temperatures, while the Moderna and Oxford-AstraZeneca vaccines are approved for two doses four weeks apart, and can be stored at more typical freezer and refrigerator temperatures. As of this writing, at least one of these three vaccines are available for regular or emergency use in Canada, the U.S., E.U., and U.K., India, Argentina, Israel, Switzerland, Kuwait, Bahrain, the U.A.E., Saudi Arabia, Chile, Costa Rica, Panama, Ecuador, and Mexico. You can check The New York Times vaccine tracker for updates.
In most places where the vaccine is available, healthcare workers and long-term care residents began receiving their first dose in mid-December, and by January people over 65 and first responders were also receiving vaccines, though rollout phases will differ by country and region.
Vaccine distribution is rolling out in phases, which will differ depending on region. Typically, healthcare workers, high-risk individuals, older adults, and essential workers are prioritized ahead of the general public. Depending on vaccine availability and rollout logistics, the vaccines may be available to everyone by late spring or early summer. Anthony Fauci, M.D., director of the National Institute for Allergy and Infectious Disease, said in December he anticipates if 75-80% of people can be vaccinated by the summer, herd immunity would be achieved in the fall and some level of normalcy may return at the end of 2021.
While individual countries may reach herd immunity on a similar timeline, the WHO does not expect worldwide herd immunity in 2021.
Reaching herd immunity is key for returning to normalcy—if only 40-50% of people receive a vaccine in that same timeline, it will take much longer for normal activities to resume. Vaccine delays could result from a number of factors, including shortages, distribution logistics, or vaccine hesitancy.
It is important to remember that immunity from the vaccine is not conferred immediately. This is true for most vaccines, but because we get them when we’re young and the population is already at herd immunity for those diseases, it’s not a concern. Since the COVID-19 vaccines require two doses given several weeks apart, and immunity is conferred two weeks after the second dose, it can take up to six weeks between the first dose and immunity.
A Boon for the Industry
This vaccine is key to returning the world to business as usual, but the effect will not be immediate. We will likely be dealing with COVID-19 restrictions, protocols, and effects throughout 2021.
As of early January, over 14 million people have received a vaccine dose across 35 countries, according to data from Bloomberg. In order to achieve herd immunity, 75-80% of the population must be vaccinated.