How the COVID-19 vaccination works and who gets it when

Christopher Hester, MD, internal medicine and clinical director, primary care services, Mount Nittany Physician Group


Editor’s note: The COVID-19 pandemic is an evolving situation. The information below was up to date at the time of publication on February 1, 20201.


Now, more than ever, we need our community to come together to stop the spread of COVID-19. COVID-19 vaccines will help slow and prevent the spread of the virus to help keep our community safe. There’s a lot of information out there about the vaccines, their effectiveness and when they will be available for the general public.


Currently, there are two vaccines authorized and recommended to prevent COVID-19, which are Pfizer-BioNTech and Moderna. Large-scale clinical trials for additional COVID-19 vaccines are also in progress.


How the COVID-19 vaccine works

Vaccines are key to preventing diseases and saving lives. Vaccines strengthen the immune system by inducing our bodies to build cells that will remember how to fight an infection. The COVID-19 vaccines can help prevent you from getting COVID-19, or if you do get the virus, can help prevent you from getting seriously ill or developing severe complications. The Pfizer-BioNTech COVID-19 vaccine and the Moderna COVID-19 vaccine require two shots in order for the vaccines to work and be most effective. The second dose is given three to four weeks after the first dose, depending on the vaccine. Both vaccines are estimated to have a 95 percent effectiveness rate after two doses. It takes time for your body to build up protection after a vaccination, so it may take a couple of weeks after receiving the second shot before your body builds up protection against the virus.


Keep in mind, the COVID-19 vaccines are a tool to help us fight off the virus, but they are not a cure. Experts will continue to learn more about the protection that the vaccines provide. To protect yourself, your loved ones and our community, it is crucial that we continue to follow the Centers for Disease Control and Prevention guidelines and everyday precautions, including wearing masks in public, maintaining social distancing of at least six feet, cleaning frequently touched surfaces and objects, staying home if you are sick and performing hand hygiene frequently. Getting vaccinated and following the CDC’s recommendations will offer the best protection from COVID-19.


COVID-19 vaccine distribution

Due to current limited vaccine supply levels, not everyone can be vaccinated right away. The Pennsylvania Department of Health has a three-phase approach to distribute COVID-19 vaccines based on CDC guidelines. Phase one focuses on reaching critical populations including health care personnel, emergency medical services, residents and staff in congregate settings and other essential workers. Once a large number of doses are available, we can move to phase two, which will expand to include vulnerable populations and those who may be at high risk. Once there are sufficient supplies, phase three will expand to the general public.


Over the next several months, the COVID-19 vaccine supply levels are projected to increase, which will allow vaccinations to be expanded to ensure the entire population has access to them.


To stop this pandemic, it is important that we continue to work together and use the resources we have available to prevent the spread of COVID-19.

For the most up-to-date information on Mount Nittany Health’s approach to COVID-19, including the latest COVID-19 vaccine news, visit