ABERDEEN PROVING GROUND, Md. — One of the more challenging jobs for any public health professional is dealing with unpredictability inherent in outbreaks like the current COVID-19 pandemic. Issues like new COVID-19 variants, explaining when and where the next surge might take place, the need to sometimes adjust recommended preventive measures, and trying to combat persistent misinformation and disinformation can all lead to increased public confusion and sometimes resistance or fatigue.
As the two-year anniversary of the World Health Organization’s March 11, 2020, COVID-19 pandemic declaration approaches, there are a number of questions on the minds of public health professionals and the public:
“When will life return to 'normal,' if ever?”
“Will we ever reach herd immunity?”
“Will I need to get a COVID booster every year — just like my annual flu shot?”
“What is the difference between a pandemic and an endemic anyway?”
Maj. James Waters and Jouelle Lamaute, who currently serve as public health nurses at the Army Public Health Center, routinely deal with these types of questions as they work to help the Army and other Services respond to and address the ongoing pandemic crisis.
Pandemic to Endemic
Waters says the first thing to understand about a potential shift from a COVID-19 pandemic landscape to one in which COVID-19 is considered an endemic disease is what the term “endemic disease” means. He describes an endemic disease as one that is consistently present in a population or region at rates that are steady and predictable.
“The amount of a disease that is usually present, or expected in a population, is referred to as the baseline or endemic level of disease,” said Waters.
According to the Centers for Disease Control and Prevention, endemic diseases are always present in a group of people or geographic region (some seasonally and some year around). Certain types of pneumonia, influenza, gonorrhea and chlamydia are examples of endemic diseases in the United States. This baseline level is not necessarily desired, but is the expected level of the disease in a population at specific periods of time.
“At the individual level, any disease, including an endemic disease, is of concern,” said Waters. “At the population level however, the presence of an endemic disease is expected. When an endemic disease occurs above the expected baseline level in a population, or a novel disease occurs in a population with widespread, sustained transmission, an outbreak occurs.”
If an outbreak occurs on a scale larger than very localized, like in a state, province, region or entire country, it is referred to as an epidemic, said Waters. When this same thing happens across the globe, as with COVID-19, the outbreak is then referred to as a pandemic. Scale is the only real difference between an epidemic and a pandemic — both of which represent levels of disease burden and transmission higher than the expected baseline or endemic level of a disease. The transition from a pandemic state to an endemic state for COVID-19 is predicted as more of the population gains some level of protection from the virus which causes the disease.
According to an article titled “Living with COVID-19: The road ahead” published in the Annals of the Academy Medicine, Singapore journal in August 2021, an endemic state for COVID-19 would involve:
- A baseline prevalence of infections with a generally mild disease profile
- Infections that can be sustainably managed by the healthcare system
- The resumption of near normalcy in human activities
The article says an endemic state is attainable for COVID-19 given the promising data around vaccine efficacy. Preventive measures such as wearing a mask and practicing social distancing remain crucial to avoid new outbreaks until high vaccination coverage is reached.
“Of course, if we progress to a state in which COVID-19 is considered endemic in our population, a new variant could push us back into an outbreak scenario, resulting in a renewed epidemic or potential pandemic if mitigation efforts aren’t sufficient,” said Waters. “This potentiality will need to be addressed with renewed pandemic preparedness and response plans.”
Returning to Normal and Herd Immunity
This leads to the question, “Will we ever return to normal?”
“Unfortunately, any estimate is no more than an educated guess at this time,” said Waters. “It isn’t clear when, or if, the U.S. will achieve herd immunity to COVID-19, but a shift from a pandemic to an endemic COVID-19 landscape is probable within the foreseeable future. Improved vaccination rates, continued adherence to social distancing and mask wearing, advancements in therapeutics, and a bit of luck regarding COVID-19 variants would go a long way toward helping us return to a more normal state.”
Lamaute added that if tens of millions of Americans remain unvaccinated, and much larger numbers of unvaccinated individuals remain worldwide, the road to herd immunity will be a long, uphill battle and likely won’t resemble the path taken to achieve herd immunity against diseases like measles in the U.S.
“Not reaching herd immunity through vaccination forces us onto the longer road, unnecessarily increasing morbidity and mortality, as well as greatly increasing the chances of facing COVID-19 variants capable of causing more harm,” said Waters.
Waters also said there is not a good understanding as to how long immunity lasts after someone becomes infected, and medical and public health professionals are learning that additional doses of the U.S. vaccines are needed to maintain immunity over time.
“What is more likely at this point is a transition to a more manageable state of COVID-19, where a return to a more normal way of living is achieved and COVID-19 persists as an endemic disease in the population,” said Waters.
One of the tools needed to keep the population protected against COVID-19 and emerging variants is vaccine boosters.
“We know without a doubt that the COVID-19 vaccines available in the U.S. work,” said Waters. “What we don’t know as of yet is how many doses of the vaccines are needed to confer long-term protection, or if the COVID-19 vaccines will be needed yearly.”
He went on to say it is now known that protection wanes within a few months, leading to recommendations that individuals get what is currently referred to as a “booster dose,” for lack of a better term, of one of the COVID-19 vaccines.
“The truth is, our clinical trials indicated levels of protection the scientific community felt were acceptable from the original vaccine series for the Pfizer, Moderna and J&J COVID-19 vaccines in the United States,” said Waters. “What we didn’t know however, was how long this level of protection would last.”
Knowledge of how many COVID-19 vaccine doses will be needed to ensure adequate protection for longer periods of time is still incomplete, said Waters.
“What we now call a booster dose of the COVID-19 vaccines may become part of the normal COVID-19 vaccine series as our knowledge grows,” said Waters. “Multiple doses of vaccines to complete a series is common in the world of vaccines.”
For example, Waters said the normal series for Hepatitis B consists of three doses, MMR is two doses, and the vaccine series for anthrax consists of five doses, followed by yearly boosters when required.
The emergence of the Omicron variant has led to more questions about the effectiveness of current vaccines and boosters against emerging variants.
“Current information available about the effectiveness of vaccines against the Omicron variant is encouraging,” said Lamaute. “Booster shots of the COVID-19 vaccines already in use are effective in protecting against severe disease caused by the Omicron variant. The CDC recommends that everyone age 12 years and older get a booster. No one should wait to get a booster if they are eligible.”
Viruses are constantly changing, including the virus that causes COVID-19. These changes occur over time and can lead to the emergence of variants that may have new characteristics, like being easier to spread. New variants of the virus are expected to occur, and these new variants must be monitored carefully. It’s harder to predict how effective current vaccines will be against future variants, but the evidence shows they have been very effective at preventing severe illness, hospitalization and death from all of the variants to date, said Lamaute.
Vaccines continue to reduce a person's risk of contracting the virus that causes COVID-19. Vaccines are highly effective against severe illness, and taking measures to reduce the spread of infection, including getting a COVID-19 vaccine, are the best ways to slow the emergence of new variants.
All FDA approved or authorized COVID-19 vaccines help protect adults and children 5 years and older against COVID-19 caused by any of the known variants, said Lamaute.
“Breakthrough infections in people who are fully vaccinated can occur, and early evidence suggests that fully vaccinated people who become infected with the Omicron variant can spread the virus to others,” said Lamaute. “It is unknown how effective our vaccines will be against future variants of COVID-19, but the recent emergence of the Omicron variant emphasizes the importance of vaccination and boosters.”
Waters explained this is also why it is so important for service members to maintain adequate levels of protection from the virus in order to maintain readiness in the Armed Services.
“This is how we protect ourselves, our loved ones, and others around us, regardless of the number of vaccine doses that ends up requiring,” said Waters.
Vaccinations, avoiding high-risk environments — such as crowded, indoor spaces — and correctly wearing good-quality masks remain the best measures to slow transmission and reduce risk from COVID-19. However, they are not 100 percent effective at preventing infection. Some people who are fully vaccinated and up to date with their booster may still experience breakthrough infections, which is the infection of a fully vaccinated person. This has proven to be the case with the Omicron variant.
The CDC recommends taking the following actions if one suspects they have a COVID-19 infection.
- Get tested if experiencing COVID-19 symptoms
- Get tested 5-7 days after close contact with someone with suspected or confirmed COVID-19
- A person should isolate if they have tested positive for COVID-19 or are experiencing COVID-19 symptoms
- Follow any applicable federal, state, local, tribal, or territorial laws, rules and regulations
Because COVID-19 spreads more easily indoors, if hosting or participating in indoor gatherings, consider using a self-test before joining indoor gatherings with others who are not in your household, said Lamaute.
“A positive self-test result means that you are infected and should avoid indoor gatherings to reduce the risk of spreading the virus to someone else,” said Lamaute. “A negative self-test means that you are either not infected or that, if infected, your levels of virus are not high enough for the test to return a positive result. Repeating the test at least 24 hours later will increase the confidence that you are not infected. Ask your health care provider if you need help interpreting your test results.”
Living with COVID-19 post pandemic
The goal of this article has been to provide some insight regarding the big question on everyone’s mind – “will we ever get back to normal?”
While nobody can speak with 100 percent certainty, the vast majority of public health experts, including those here at APHC, agree the future will likely involve a new normal, rather than a return to a pre-COVID-19 world.
“How much this new normal differs from the world we knew in 2019 will largely be up to us and our collective actions as we move forward,” said Waters. “At a minimum, we will forge our way into the future, living with the memories, and scars for some, from the last several years. There is a very strong possibility that COVID-19 is an illness we will have to learn to live with in a post-pandemic world – just as we do other potentially severe respiratory illnesses.”
In a COVID-19 endemic “new normal” future, transmission, illness and fatalities will still occur, but at a much more manageable rate, said Waters. To prevent backsliding once the endemic state is reached, Waters said that people would need to continue being vigilant with some by now familiar recommendations for the collective population:
- Routinely wash your hands
- Cover your mouth and nose with the inside of your elbow when coughing or sneezing
- Follow COVID-19 testing and vaccination recommendations
- Limit your exposure to others when you, or they, display COVID-19 related symptoms
- Follow local COVID-19 guidelines
“Until high levels of sustained population immunity are achieved, social [physical] distancing and mask wearing will remain valuable tools to prevent outbreaks in a post pandemic world,” said Waters
The U.S. Army Public Health Center enhances Army readiness by identifying and assessing current and emerging health threats, developing, and communicating public health solutions, and assuring the quality and effectiveness of the Army’s Public Health Enterprise.