With the promise of a new year comes the hope of a new start for all of us. As many of you may already be aware, the FDA has approved the emergency use of two vaccines to protect against COVID-19. These vaccines use a new kind of technology to induce antibody production. In addition, there are three other vaccines currently in the end-stage testing phase and will likely be available for distribution early this year. If all goes well, we may soon have a chance to go “back to normal.”

Should I get vaccinated?

Yes. Currently, vaccinations are reserved for the highest-risk groups, such as healthcare workers, long-term care facility residents. According to the CDC, the next wave of vaccinations will be offered to frontline essential workers and people aged 75 years and up. After that, priority will go to those between 65-74 years old, those between 16-64 with underlying medical conditions, and other essential workers. Your responsibility should be to know what group you fall under and to get vaccinated promptly when the time comes.

What if you already contracted COVID-19 and recovered? While natural infection and recovery do grant a period of protection from reinfection, this period is only estimated to be 90 days. For this reason, if you have recovered from COVID-19, it is recommended to wait until after those 90 days of protection have passed to be vaccinated, to maximize the duration of your protection.

Kinds of vaccines

As of the writing of this blog post, there are two vaccines approved for use: the Pfizer vaccine and the Moderna vaccine. Both use a newer kind of vaccination technology which involves the delivery of mRNA (genetic material) that teaches our body how to make a protein which then triggers the immune response to develop antibodies that protect us against COVID-19. mRNA vaccines do not contain the virus itself, meaning there is no chance of contracting COVID-19 from either the Pfizer or the Moderna vaccine. There is no interaction between our own DNA and the mRNA from the vaccine either, as our body uses the mRNA instructions to create the protein, then quickly disposes of them.

The other three vaccines currently in end-stage testing are from AstraZeneca, Janssen, and Novavax. AstraZeneca and Janssen’s vaccines are vector vaccines, which means that they contain a harmless replica of the virus which your body can use to create antibodies in preparation for defending you against the real virus.

Finally, the Novavax vaccine is a protein subunit vaccine, which simply contains an engineered protein that prompts the immune system to create those all-important antibodies.

Herd immunity

If you recall such diseases as smallpox or measles, which were very contagious and virulent diseases in their time, you may wonder why they rarely break news headlines anymore. The reason behind that is a concept known as herd immunity, which occurs when a large enough proportion of a community (the herd) gains immunity to a disease. When this critical mass is achieved, even someone in the herd who has not been immunized is far less likely to contract the disease, such that the entire community gains protection. This can be achieved either through natural infection (and recovery) or vaccination.

For COVID-19, experts estimate that the “critical mass” of inoculation required for herd immunity would be around 70%. For the U.S., that means around 230 million people would need to acquire immunity to the coronavirus to achieve herd immunity. To put that in perspective, since December 21^st (the first day vaccinations began in the U.S., a little under 6 million doses have been administered. When calculations of rough estimates regarding natural infections and recoveries are factored in, we can say that we are approximately 10% of the way to herd immunity. Vaccination is by far the fastest and safest path to herd immunity and a return to some semblance of normal.

Emergency Use Authorization

The FDA has issued an Emergency Use Authorization (EUA) for both the Moderna and Pfizer vaccines. This means that while they have not been approved for official use by the FDA, it has been authorized for use in individuals 18 years and older due to the extenuating circumstances of the global pandemic. Because of this EUA, the side effects have not been fully documented across a wide enough population to be predictable. However, general side effects have been reported to include injection site pain, and mild flu-like symptoms.

The Pfizer vaccine comes in two doses, given 3 weeks apart, and has an inoculation efficacy of 95%. However, due to storage and transportation logistics, is more difficult to distribute.

The Moderna vaccine comes in two doses, given 4 weeks apart, and has been demonstrated to have an inoculation efficacy of 95%. The Moderna vaccine is stable at the temperature of a standard refrigerator for up to 30 days, making distribution a bit more flexible.

The AstraZeneca vaccine also comes in two doses, given 4 weeks apart, and sports an inoculation efficacy between 70% and 90%. Improving upon distribution flexibility even further, the AstraZeneca vaccine can be stored at standard refrigerator temperatures for up to 6 months. This vaccine is expected to be the next one approved for an EUA (sometime early in 2021).

The Janssen vaccine capitalizes on simplicity, only requiring one dose. Early results suggest that it would have an inoculation efficacy of around 97%, and the current timeline suggests that it may be approved for a EUA sometime around mid-2021.

The Novavax vaccine is the furthest back in the timeline of clinical trials and distribution. It will be another two-dose vaccine, and its inoculation efficacy has not yet been determined. It is unlikely that the Novavax vaccine will be available before late-2021.