Does our immune system function longer by having a vaccination or from having a disease? Both options provide information to our immune systems to recognize and quickly respond the next time the foreign invader shows up. However, which lasts longer?
https://www.acsh.org/news/2020/12/14/why-vaccine-can-provide-better-immunity-actual-infection-15214 Scientists may argue that a vaccine can be tailored to the idiosyncrasies of a specific virus and offer a better and longer-term protection. This is true with the mRNA viruses recently developed to focus our immune response to specific antigens in the virus.
I have been asked the question about how many times can a person get COVID-19. The research that I have done shows that it can happen, but it is rare. The link above describes two cases of reinfection of COVID-19. One was a person in Hong Kong (https://academic.oup.com/cid/advance-article/doi/10.1093/cid/ciaa1275/5897019) who had no symptoms after becoming infected a second time. However, a totally different story is shown when a person in Reno, Nevada (https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3680955)
recaught the disease and had more severe reactions compared to the first infection.
Is it the virus or the person? Our immune systems change over time. Could the immune system of the Hong Kong subject have been significantly better the second time infection rang the doorbell? And the Reno subject could have caught it again with a challenged immune system? Or a third possibility is that the virus could have mutated and been less viral in Hong Kong and more viral in Reno. These unknowns we will never know. But it shows that reinfection is possible with mixed results.
https://www.webmd.com/healthy-aging/guide/seniors-boost-immunity#1 Growing older has many health factors to consider. One is our immune system. T and B cells attack foreign invading cells. They remember the molecular structure of the attacker and respond with weapons drawn when it shows up the next time.
Our bodies make fewer T cells as we age. (https://www.frontiersin.org/articles/10.3389/fimmu.2019.01787/full). T cells are the aggressors in defending our bodies. B cells provide the antibodies to neutralize the enemy. How long does our immune system remember an invader? It depends on many factors.
https://www.cdc.gov/vaccines/schedules/hcp/imz/adult.html Why do we get a flu shot annually and hepatitis lasts for decades. Booster shots are recommended at various times after the initial inoculation for many vaccines. Does the body remember a disease for life? Yes, measles is one of them. Get it once and you never need a vaccine or booster shot.
Medical researchers do not know how long a COVID-19 vaccine will last. It is hoped long enough to get through this pandemic with a little breathing room. However, it might become a staple vaccine in the future that people get every year. No one knows yet.
The same is true with the people who caught the SARS-CoV-2. Will their natural immunity provide protection for two years, five years, or ten years down the road? Vaccines can be adjusted to tweak a better immune response and provide longer protection. Just because a person has had a vaccination does not imply, they are good to go for life. Too little is known now.
People can test positive or negative for coronavirus. They have the virus, or they do not. After they have recovered, our bodies produce antibodies that provide protection. A COVID-19 antibody test can determine if a person has had the virus or not. Many blood donation centers are providing that antibody test.
There are studies that indicate our bodies can recognize a SARS virus years, even decades later, but it is not the SARS-CoV-2 virus that causes COVID-19. That coronavirus is too new to know how long our bodies will be vigilant.
The answer to the original question regarding the long-term immune response of a vaccine or natural immunity is that it depends on the disease and the age of the person involved. Like everything else in medicine, ask a question and hope for clarity in the answer. It almost never comes.
Live Longer & Enjoy Life – Red O’Laughlin – RedOLaughlin.com