A Q&A on Variants and Vaccinations
(As some of the points within are time-sensitive, an editor’s note that the information within was current as of Monday, Sept. 25)
In Nov. 2022, we asked the question “Is the Pandemic Really Over?”, and profiled our role in combatting COVID-19, our support for at-home testing, and our preparations for what is next.
Jump ahead 10 months and we’ve been hearing and reading a lot about an uptick in COVID-19 cases, possible new variants, and vaccine availability. To learn more, we spoke with MRIGlobal’s Melissa Moses, Senior Scientist. In 2019, she was supporting the Defense Intelligence Agency (DIA) efforts related to the country’s COVID-19 response when she met our Dr. Gene Olinger and then joined MRIGlobal. Though currently on active duty with the U.S. Marine Corps, she supports our team when a project needs her unique perspective and expertise.
What existing or new COVID variants have public health officials considered in preparation for this fall?
The EG.5 variant, or, informally, Eris (nicknamed after the Greek goddess of strife and discord), has recently taken over as the most common circulating variant in the U.S. and UK and is growing as a fraction of infections in other countries. Globally it makes up about 21 percent of all new cases. The WHO labeled EG.5 a “variant of interest,” joining variants XBB.1.16 and XBB.1.5, due to its “notable rise” in global prevalence during recent weeks. While still a descendant of Omicron, EG.5 is on a slightly different branch of the family tree from the recently dominant XBB subvariants. EG.5 has a mutation on the spike protein that seems to reduce the effectiveness of existing antibodies, or frontline immunity. But for now, there is no indication that EG.5 is causing more severe disease, but this is something that may change as scientists and healthcare professionals monitor indicators such as hospitalizations, ICU admissions, and deaths.
Fortunately, EG.5 is still closely related to the XBB variant, which is the target of the updated vaccines that have recently been approved. This means these booster vaccinations should still give strong protection against any infection in the short term and an excellent boost in protection against severe disease in the medium to longer term.
For more on our work supporting infectious disease diagnostics to detect these variants, read about our involvement in the National Institutes of Health’s (NIH) Rapid Acceleration of Diagnostics (RADx®) initiative. You can also read about our work helping in vitro diagnostic manufacturers avoid developmental traps.
Are there other variants causing concern?
Unfortunately, there is another variant called BA.2.86, nicknamed Pirola, that is popping up. As of Aug. 31, there have been 27 cases reported in eight countries—Denmark (10), Sweden (four), Portugal (two), UK (three), Israel (one), South Africa (two), Canada (one), and the U.S. (four). The variant has been detected in wastewater in several additional countries, including Switzerland and Thailand, as well as five U.S. states. Usually, this isn’t enough to warrant concern, but some details are noteworthy and concerning. It is thought to have evolved from Omicron BA.2, which circulated globally in early 2022, or the original Omicron variant, B.1.1.529, which circulated widely in late 2021 and early 2022. However, this newer variant appears to be much different than its predecessors and the currently circulating XBB-derived variants, due to more than 35 spike protein mutations. This is a significant amount of change; it’s as big of an evolutionary jump as the initial Wuhan strain to Omicron, but in a much shorter period of time, which means it may be more able to skirt existing immunity and cause infection in people who have previously had COVID-19 or been vaccinated against it.
Of the first seven known cases, six are without travel history (and one U.S. case was a traveler from Japan). There is vast geographical distribution of the cases identified (Israel, the U.S., Denmark, and the U.K.) and we are seeing BA.2.86 in country-level wastewater samples without corresponding reported cases. These factors point to undetected community transmission, which means it is spreading, and we are playing catch up to identify infected individuals.
One U.S. lab found that BA.2.86 has 16 known mutations that significantly escape current antibodies. In other words, this will likely infect many people, regardless of prior immunity. We don’t yet know if this is more severe than Omicron or Delta, but scientists hypothesize it will probably be about the same level of severity. This is because SARS-CoV-2 has historically evolved to escape antibodies (the body’s first line of defense) rather than T-cells (the body’s second line of defense) that primarily protect us from severe disease.
The WHO and CDC announced recently that they have classified this a “variant under monitoring.” If the WHO determines this is a new variant of concern—the highest risk classification—it will be assigned a Greek name; next in line is “Pi.” In the coming weeks, we should get further details from scientists and pharmaceutical companies regarding how our immune systems are reacting to BA.2.86, if this will impact transmission rates going into the fall, and whether the tools developed such as the vaccines, Paxlovid, and antigen tests, will work against BA.2.86.
Should we expect a new COVID-19 vaccine this fall?
There will not be a “new” vaccine, but there will be an updated booster targeting variant XBB.1.5, which should also be a good match to the EG.5 variant that currently comprises the majority (21 percent) of new cases worldwide. Moderna, Pfizer, and Novavax all plan to have boosters on the market this fall, likely in mid-late September. Each of the pharmaceutical companies submitted the required safety and efficacy data. Following a U.S. Food and Drug Administration meeting on Sept. 11 to approve the shots and authorize who they should be given to, the Advisory Committee on Immunization Practices (ACIP) met on Sept. 12. The ACIP, which is part of the CDC, develops recommendations for U.S. immunizations, including ages when vaccines should be given, number of doses, time between doses, and precautions and contraindications. They recommended the new Pfizer and Moderna COVID-19 booster vaccines for anyone six months and older. After these meetings, the CDC granted final approval and the boosters are available as of mid-September.
This is a very simplified breakdown of the process:
Pharmaceutical companies develop and test new booster formulas 🡪 gather data 🡪 submit data and request for approval to FDA 🡪 FDA reviews data 🡪 (if safe) approves booster 🡪 CDC reviews data and makes recommendations for who should get a booster 🡪 boosters released to public
In 2022, eligibility was dependent on the manufacturer and is the same this year:
Moderna: 6 months and older
Pfizer: 6 months and older
Novavax: 18 years and older
Why do boosters need to be updated? If the vaccine worked last year, shouldn’t it work this year?
Pharmaceutical companies continuously develop new boosters because, as with any virus, SARS-COV-2 continuously mutates. Scientists and health care professionals are in an ongoing battle, trying to stay one step ahead of a virus that continuously mutates to evade natural and pharmacological defenses. Vaccine boosters are one line of defense that scientists change in response to how the virus is changing. Though they do not have to redesign a whole new vaccine, they are able to adjust the vaccines to target the more prevalent strain to be more effective in stopping infections and severe disease. The original vaccine was monovalent, as it was developed to target the Wuhan variant, which was most prevalent at that time. In 2022, the vaccine formula was updated to bivalent, targeting two variants—Wuhan and Omicron BA.4/5. Now we have boosters available this fall that will be effective against multiple different strains, adding to the protection offered by previous vaccines and boosters.
The CDC released a report this month showing that a dose of last year’s bivalent (two-strain) mRNA COVID-19 vaccine booster pushed effectiveness against emergency or urgent care to 80 percent among preschool children, 70 percent after three monovalent Pfizer/BioNTech doses, and 46 percent after two Moderna monovalent (single-strain) doses. This means that for preschoolers who were boosted with a bivalent mRNA vaccine and contracted the virus, 80 percent did not have to seek care at the emergency department or urgent care.
For more on mRNA vaccines – their history, why they’ve been so critically important to the COVID response, and what’s next for their use in supporting global health – listen to this episode of the new “Science Diction” podcast from MRIGlobal.
What should people expect from the COVID-19 vaccine booster this fall?
This fall’s COVID-19 vaccine is based on the XBB subvariants. The FDA’s Vaccines and Related Biological Products Advisory Committee (VRBPAC) met on June 15, 2023, to discuss and make recommendations for SARS-CoV-2 strain(s) for updated COVID-19 vaccines for use in the United States beginning in the fall of 2023. At the time scientists were first formulating the new boosters, the XBB subvariants were the most popular circulating strains. However, since that time the EG.5 has overtaken the XBB subvariants as the most predominant circulating strain. The good news is that the EG.5 is similar enough to the XBB subvariants that the boosters will be effective against both. Many scientists agree that unlike other respiratory diseases such as influenza and RSV, COVID has yet to fall into a seasonal pattern, so what to expect from the virus this fall and winter is uncertain.
Based on historical health and trend data the best time to get boosted is right before a wave, providing fresh protection against a surge of infections, though this can also be hard to time and slightly subjective. However, in looking at the increase of cases currently and historical trends, it appears we are heading into another wave this fall. The best time to get boosted is as soon as possible once the vaccines are released.
Is the goal of the COVID-19 vaccine to keep people from catching the virus or just from getting as sick as they would without it?
There is a distinction between protection against infection and protection against severe disease. Everyone should be vaccinated to protect against severe disease. While people who have been vaccinated can still be infected by the virus, a vaccine is designed to help your immune system fight infections faster and more effectively, so they are statistically less likely to go on to get severely ill. This helps keep people out of the hospital and in need of more invasive medical interventions. However, because protection against infection begins to fade over time, booster shots help bolster that protection, especially when they are targeted to the predominant strain that is circulating at the time.
However, the effective impact on reducing the burden of severe disease on the hospital system will be predicated on the number of people who get the vaccine. As of this spring (May 2023) only 17 percent of the U.S. population has received an updated booster and 69.5 percent have completed an initial series. Of the 17 percent who received a booster, less than half (45 percent) of adults 65 and older have received a bivalent shot, while rates for all other age groups sit at around 20 percent.
Why do you think vaccination rates are so low?
Vaccine fatigue over the pandemic and the general belief that COVID-19 is “over” are some of the reasons people are not going to get boosted. A poll conducted by Gallup in June found that 64 percent of Americans think the pandemic is over in the U.S. and only 18 percent are worried about contracting the virus. Ipsos and Axios released a survey with similar findings in May, two months after the U.S. ended the national COVID-19 public health emergency amid a downward trend in cases, hospitalizations, and deaths. It found that many Americans are becoming weary of recommendations for protection, including masking, testing for the virus, and getting vaccinated. Additionally, the sometimes confusing and often changing guidelines for who and when people should get vaccinated is contributing to many opting not to bother. All three manufacturers (Pfizer, Moderna, and Novavax) have noted that they are preparing for the federal government to shift vaccine distribution to the private market, meaning manufacturers will sell their updated shots directly to health-care providers at higher prices. Previously, the government purchased vaccines directly from manufacturers at a discount to distribute to the public for free.
Generally, how do vaccines work and are there different types?
Vaccines train your immune system to create antibodies, just as it does when it’s exposed to a disease-causing pathogen, but it does this prior to an exposure so that when/if you encounter the pathogen your body knows how to fight and protect against it. It does this by producing pathogen-specific antibodies, which are proteins produced naturally by the immune system to fight disease. Most vaccines contain only killed or weakened forms of the germ (viruses or bacteria) which means they do not cause the disease or put you at risk of its complications.
Many people think that a vaccine must be an injection, but not all vaccines are shots. Vaccines can be given via an injection (COVID, flu, measles, etc.), nasal spray (flu mist), liquid (polio, rotavirus), or pill (typhoid), but scientists are working to formulate other means such as dermal patches that can also be used as a vaccine.
While vaccines do a great job at preventing people from contracting a disease and developing symptoms, nothing is 100 percent perfect, so it’s important to manage expectations. Since everyone is different, every experience will also be different. Some people will experience side effects from a vaccine and some won’t. Some will be completely protected, while some will not. For individuals who aren’t completely protected, having been vaccinated gives them a head start in fighting the pathogen that they would not otherwise have. They are better equipped to recognize and defend against the virus, which leads to better outcomes – less severe symptoms, less shedding of the virus (less contagious), and less time feeling sick. This reduces the amount of people they could potentially spread the disease to and the amount of time they will have symptoms.
The overall goal of a vaccine and vaccination is to keep individuals healthy by preparing their immune system to defend against a disease-causing pathogen so if they are ever exposed, they are better equipped avoid infection. However, if they do get infected, it will keep them from developing severe symptoms and lessen the overall duration of the illness. By reducing the number of infected people or people who can’t spread it to as many people, the overall population is healthier, which is better for everyone.
Is there a difference between the terms vaccination and immunization?
There are a lot of terms used when talking about vaccines that can sometimes confuse people or are used interchangeably when they are actually different. Before we talk about the purpose of a vaccine, we should first get a baseline of what some of the words and phrases mean. Many people use the terms “vaccination” and “immunization” interchangeably, and although they are very similar, there is a difference.
Vaccination is the act of introducing a vaccine into the body to produce protection from a specific disease. It is a safe and effective way of protecting you against harmful diseases before you come into contact with them. A vaccine uses your body’s natural defenses to build resistance to specific infections and makes your immune system stronger.
Immunization is a process by which a person becomes protected against a disease through vaccination. A “vaccine” is what is given during a vaccination, it is the formula or preparation that is administered through an injection, liquid, nasal spray, or pill; it’s the “magic sauce” of immunity. So, vaccination (the act) stimulates the immune system (the process) using a vaccine (the substance) to become protected against a specific disease.
People get vaccinated to protect against diseases and illnesses but there is a difference between these two as well. Outside medical literature or professional medical publications, the easiest way to think about these two is that patients suffer “illnesses” (symptoms); doctors diagnose and treat “diseases”(what is causing the symptoms). The purpose of a vaccine is to prevent or control the spread of a disease-causing pathogen (usually a virus or bacteria). If enough people are vaccinated, then the disease either cannot spread at all and “burns out” or cannot spread to enough people to continue to propagate and eventually “burns out.” This is how the world conquered smallpox – enough people around the world became immune either through vaccination or exposure that there were not enough available hosts and it was eradicated.
What do you think this round of COVID-19 might look like?
For an indication of what our winter might look like in the northern hemisphere, scientists are looking at what is going on in the southern hemisphere, where they are just coming out of their winter. What they are seeing is that winter in the southern hemisphere is looking a lot like what it did last year. RSV rates in South America were about as high as they were last year and flu hospitalizations in Australia came early and were as high as they were last year. If this holds true for the northern hemisphere, we should expect a repeat of last year: an early RSV wave, followed by an early flu wave, and COVID rates holding steady. Pandemic fatigue, varying immunity rates in the community, and an increase in tools such as vaccines, boosters, medical interventions, and readily accessible tests will all contribute to what fall and winter in 2023 will look like. However, the wave for all three heavily depends on how, and if, the public utilizes those tools.
GETTING STARTED AT MRIGLOBAL
Contact MRIGlobal for further information about our work with infectious diseases. Through an interdisciplinary approach, we provide scientific and subject matter expertise for development of medical countermeasures research against specific threats, while expanding and accelerating the delivery of high quality clinical diagnostic products.
To discuss how we can help your project be successful, contact us today.
SIGN UP FOR OUR NEWSLETTER
Sign up for the MRIGlobal newsletter! It’s the best way to get the latest updates in the world of applied scientific engineering research delivered directly to your inbox.