COVID Vaccine FAQs: Will We Need the COVID Vaccine Annually Like the Flu Shot?
As COVID-19 vaccines are administered, many hope that once the virus is less threatening, life will return to normal. Potentially one or more strains of the virus may stay with us for the next few years and the COVID vaccine could become an annual ritual rather than a one-time event.
According to Johnson and Johnson CEO Alex Gorsky, the virus’s potential for mutation may make an annual vaccination necessary to protect against possible variants of the original virus. “Every time [the virus] mutates, it’s almost like another click of the dial so to speak where we can see another variant,” Gorsky recently told reporters. “Another mutation…can have an impact on its ability to fend off antibodies or to have a different kind of response not only to a therapeutic but also to a vaccine.”
Health officials will continue to watch for new variants of the virus so they can produce vaccines to protect the public. The Johnson and Johnson vaccine, recently approved for emergency use in the US, is a one-dose vaccine. Unlike the Johnson and Johnson adeno vaccine, the Pfizer and Moderna vaccines are mRNA vaccines (which require two doses).
How mRNA Vaccines Work
Human cells contain DNA, which acts as a set of instructions for our cells. Inside our cells, the DNA code is read and copied into a molecule called mRNA. The mRNA carries instructions that allow our cells to create proteins. The mRNA vaccines use this normal cellular process to help cells mount an immune response against COVID-19.
The COVID-19 mRNA vaccines contain instructions for human cells to make a harmless piece of the spike protein that is found on the surface of the SARS-CoV-2 virus. When the vaccine is injected, dendritic cells use the mRNA to create the spike protein. The cells with the spike protein travel to a lymph node, where other cells of the immune system recognize the protein as a foreign substance and make antibodies to protect against it. This way, if we are exposed to the COVID-19 virus after vaccination, our immune systems recognize the protein and are primed to fight against the infection.
How Adenovirus Vaccines Work
Adenovirus vector vaccines use a harmless form of a virus that does not cause illness in humans and which most people are unlikely to have encountered naturally. Two genes of the adenovirus are removed, and a SARS-CoV-2 spike protein gene is substituted for one of the genes.
When the vaccine is injected into a human muscle, it releases the adenovirus vector that is taken up by the cells. The adenovirus releases the DNA for the spike protein, and the host cell creates the protein from the new DNA. The cell displays the spike protein on its surface. The immune system recognizes the protein and fights the foreign substance by producing antibodies and killing the infected cells.
People Who Should NOT Get the COVID-19 Vaccine
Although the risk of adverse reactions to the COVID-19 vaccine is low, there are some groups of people who should not get the vaccine. They include:
- People who have had a severe or immediate allergic reaction to the vaccine, one of its ingredients, or polysorbate
- People under the age of 16
- People currently isolating or experiencing symptoms of COVID-19; these people can get vaccinated after their symptoms are resolved
Does the Vaccine Become Less Effective Over Time?
At this time, it’s unknown how long the antibodies produced by the vaccine will offer immunity from the virus. If immunity is not permanent and the COVID-19 virus creates new variants each year like the influenza virus, the vaccine may need to be adjusted and administered each year in order to fight new strains.
“[Immunity] may last longer than a year, but it’s unlikely to be permanent the way two doses of the measles vaccine is,” said Dr. Andrew Pavia, an Infectious Disease Specialist at University of Utah Health. “So at some point, it’s likely that we will need to boost people, but we don’t know how frequently that will need to be.”
Although many of us would like to understand how COVID-19 will affect our lives in the future, the virus is still too new for experts to predict its behavior accurately. The success of the COVID-19 vaccination will depend on how the virus behaves after the population has been inoculated against it.
“Over time, what the virus will need to do to survive is infect people that have been vaccinated,” said Dr. Pavia. “If variants occur naturally where the virus is more able to infect people who’ve been vaccinated, then we’ll start to see those variants spread more easily.”
Just as the flu vaccine changes every year to accommodate new strains of the flu, experts anticipate the COVID-19 vaccine will also require adjustments to deal with new COVID variants.
|Written by Juliette Willard
Healthcare Communications Specialist
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